name: PR Policy

on:
  pull_request:
    types: [opened, reopened, synchronize, edited, labeled, unlabeled, ready_for_review]

# Temporary outage smoke test (PLAT-87): inlined on repo self-hosted runner.
# Job name preserves required check "policy / pr".

concurrency:
  group: "policy-${{ github.event.pull_request.number }}"
  cancel-in-progress: true

permissions:
  contents: read
  issues: read
  pull-requests: read

jobs:
  pr:
    name: policy / pr
    runs-on: self-hosted
    timeout-minutes: 10
    steps:
      - name: Validate PR
        uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3  # v9.0.0
        env:
          JIRA_CLOUD_ID: ${{ secrets.JIRA_CLOUD_ID }}
          JIRA_SERVICE_ACCOUNT_EMAIL: ${{ secrets.JIRA_SERVICE_ACCOUNT_EMAIL }}
          JIRA_API_TOKEN: ${{ secrets.JIRA_API_TOKEN }}
        with:
          script: |
            // ── Pure validation functions ────────────────────────────────────────────
            // Extracted and exercised by test/pr-policy.test.mjs via PR_POLICY_TEST.
            // These functions have no side effects and make no API calls.

            const CONV_TYPES = ['feat','fix','docs','style','refactor','perf','test','build','ci','chore','revert','release'];
            const REQUIRED_H2 = ['Summary','Validation','Tests','Notes'];

            // AI-attribution footer patterns — case-insensitive, multiline.
            // Matches Co-authored-by: trailers naming known AI tools and "Generated by/with"
            // phrases. Does NOT flag generic prose like "uses AI" or "AI-powered".
            // GPT variants: gpt-3, gpt-4, gpt-4o, gpt-5, gpt-o, etc. covered by gpt-[a-z0-9]+.
            const AI_FOOTER_RE = /^(?:co-authored-by:\s+(?:claude|chatgpt|gpt-[a-z0-9]+|copilot|github\s+copilot|gemini|cursor(?:\s*ai)?|codeium|anthropic|openai|codex)\b|generated\s+(?:with|by)\s+(?:claude(?:\s+code)?|github\s+copilot|chatgpt|codex|gpt-[a-z0-9]+|gemini|codeium|cursor(?:\s*ai)?|anthropic|openai)|🤖\s+generated\b)/im;

            function validateTitle(title, isDependabot, jiraMaybeExempt) {
              const errs = [];
              if (title.length > 120) errs.push('Title is ' + title.length + ' chars — max 120');
              const m = title.match(/^(feat|fix|docs|style|refactor|perf|test|build|ci|chore|revert|release)(\([^)]+\))?(!)?: (.+?)(\s+\((DEV|PLAT|SEC)-\d+\))?$/);
              if (!m) {
                errs.push('Title must match: type(scope): description (KEY-NNN). Allowed types: ' + CONV_TYPES.join(' '));
                return errs;
              }
              const desc = m[4];
              const jiraSuffix = m[5];
              if (desc.endsWith('.')) errs.push('Description must not end with a period');
              if (!/^[a-z]/.test(desc)) errs.push('Description must start with a lowercase letter');
              if (!isDependabot && !jiraSuffix && !jiraMaybeExempt) {
                errs.push('Missing Jira key — expected (DEV-NNN), (PLAT-NNN), or (SEC-NNN) at end of title');
              }
              return errs;
            }

            function getJiraKey(title) {
              const m = title.match(/\((DEV|PLAT|SEC)-(\d+)\)$/);
              return m ? m[1] + '-' + m[2] : null;
            }

            function validateBranch(branch, isDependabot) {
              if (isDependabot) return [];
              const errs = [];
              // Segment must be proper kebab-case: no consecutive hyphens, no trailing hyphen.
              const m = branch.match(/^(feature|fix|hotfix|chore|docs|refactor|release)\/([a-z0-9]+(?:-[a-z0-9]+)*)$/);
              if (!m) {
                errs.push('Branch "' + branch + '" must match prefix/kebab-case (no consecutive/trailing hyphens, no uppercase, one segment). Prefixes: feature fix hotfix chore docs refactor release');
                return errs;
              }
              if (/(?:DEV|PLAT|SEC|INFRA)-\d+/i.test(m[2])) errs.push('Branch segment must not contain a Jira key');
              return errs;
            }

            function validateBody(rawBody, isDependabot) {
              if (isDependabot) return [];
              if (!rawBody || !rawBody.trim()) return ['PR body is empty'];
              const errs = [];
              // Strip fenced code blocks line-by-line before scanning headings.
              // Fence markers: backtick (0x60) or tilde. Up to 3 leading spaces allowed
              // (CommonMark spec). Use charCode to avoid literal backtick in source
              // (which confuses actionlint's expression scanner).
              const TICK = String.fromCharCode(0x60);
              const bodyLines = rawBody.split('\n');
              const stripped = [];
              let inFence = false;
              let fenceChar = '';
              let fenceLen = 0;
              const fenceRe = new RegExp('^ {0,3}(' + TICK + '{3,}|~{3,})');
              for (const line of bodyLines) {
                if (!inFence) {
                  const fm = fenceRe.exec(line);
                  if (fm) {
                    inFence = true;
                    fenceChar = fm[1][0];
                    fenceLen = fm[1].length;
                    stripped.push('');
                  } else {
                    stripped.push(line);
                  }
                } else {
                  const fm = fenceRe.exec(line);
                  if (fm && fm[1][0] === fenceChar && fm[1].length >= fenceLen && line.trim() === fm[1]) {
                    inFence = false;
                    stripped.push('');
                  } else {
                    stripped.push('');
                  }
                }
              }
              const cleaned = stripped.join('\n').replace(/<!--[\s\S]*?-->/g, '');
              const h2s = Array.from(cleaned.matchAll(/^## (.+)$/gm)).map(function(x) { return x[1].trim(); });
              if (h2s.length !== 4) {
                errs.push('Body must have exactly 4 ## headings (Summary/Validation/Tests/Notes), found ' + h2s.length + (h2s.length ? ': ' + h2s.join(', ') : ''));
                return errs;
              }
              for (let i = 0; i < 4; i++) {
                if (h2s[i] !== REQUIRED_H2[i]) errs.push('Heading ' + (i + 1) + ': expected "## ' + REQUIRED_H2[i] + '", got "## ' + h2s[i] + '"');
              }
              const sectionParts = cleaned.split(/^(?=## )/m).filter(function(p) { return p.startsWith('## '); });
              for (let i = 0; i < Math.min(sectionParts.length, 4); i++) {
                const content = sectionParts[i].replace(/^## [^\n]*\n?/, '').trim();
                if (!content) errs.push('## ' + REQUIRED_H2[i] + ' section is empty');
              }
              return errs;
            }

            function validateCommitSubject(subject) {
              const errs = [];
              if (subject.length > 72) errs.push('Commit subject is ' + subject.length + ' chars — max 72');
              const m = subject.match(/^(feat|fix|docs|style|refactor|perf|test|build|ci|chore|revert|release)(\([^)]+\))?(!)?: (.+)$/);
              if (!m) {
                errs.push('Not conventional: "' + subject.slice(0, 60) + (subject.length > 60 ? '\u2026' : '') + '"');
                return errs;
              }
              const desc = m[4];
              if (!/^[a-z]/.test(desc)) errs.push('Commit description must start with a lowercase letter');
              if (desc.endsWith('.')) errs.push('Commit description must not end with a period');
              if (/\s+\((DEV|PLAT|SEC)-\d+\)$/i.test(subject)) errs.push('Commit subject must not carry a Jira key suffix — only the PR title does');
              return errs;
            }

            function isSyncMergeCommit(commit) {
              if (!Array.isArray(commit.parents) || commit.parents.length < 2) return false;
              const subject = (commit.commit && commit.commit.message ? commit.commit.message : '').split('\n')[0];
              return /^Merge (?:branch|remote-tracking branch) '[^']+' into \S.+$/.test(subject);
            }

            function detectAiFooter(text) {
              return AI_FOOTER_RE.test(text);
            }

            function isWorkflowFilename(filename) {
              return /^\.github\/workflows\/[^/]+\.ya?ml$/.test(filename) ||
                /^workflow-templates\/[^/]+\.ya?ml$/.test(filename);
            }

            // Matches action manifests at any depth (e.g. .github/actions/**/action.yml).
            function isActionManifestFilename(filename) {
              return /(?:^|\/)action\.ya?ml$/.test(filename);
            }

            // Combined predicate — any file that the supply-chain scanner must process.
            function isPolicyFilename(filename) {
              return isWorkflowFilename(filename) || isActionManifestFilename(filename);
            }

            // Returns 'workflow', 'action', or null for non-policy files.
            // Used by classifyFileStatus to prevent cross-kind rename diffing.
            function policyFileKind(filename) {
              if (isWorkflowFilename(filename)) return 'workflow';
              if (isActionManifestFilename(filename)) return 'action';
              return null;
            }

            // FNV-1a 32-bit hash of a string — used to produce content fingerprints
            // for line-specific violations so changing the payload changes the
            // fingerprint even when the violation remains on the same line.
            function fnv1a32(str) {
              let h = 2166136261;
              for (let i = 0; i < str.length; i++) {
                h = Math.imul(h ^ str.charCodeAt(i), 16777619) >>> 0;
              }
              return h.toString(16).padStart(8, '0');
            }

            // Strip the trailing [fnv:XXXXXXXX] content-hash token from a violation
            // string before emitting it to users. The hash is purely internal.
            function stripHash(msg) {
              return msg.replace(/ \[fnv:[0-9a-f]{8}\]$/, '');
            }

            // Deterministic line scanner for workflow YAML content.
            //
            // Block-scalar tracking: any YAML key whose value begins with | or >
            // (including explicit indent/chomp forms |2, |2-, |-2, >+2, etc.)
            // starts a block scalar. Lines inside ANY block scalar are not parsed
            // as structural YAML keys — they are content. For run: block scalars,
            // the content is still scanned for expression injection (expressions
            // must flow through env:). uses: block scalars are rejected because an
            // action ref must be an inline scalar to validate its immutable pin.
            // For other non-run block scalars (e.g. script:, name:), the content
            // is skipped entirely — no uses: or run: detection.
            //
            // Quoted keys: "uses", 'uses', "run", 'run', "permissions" are all
            // recognized in addition to their unquoted forms.
            //
            // Quoted action refs: `uses: "owner/repo@sha" # vX.Y.Z` correctly
            // parses the comment outside the closing quote as the version annotation.
            //
            // Fails closed on YAML forms the line scanner cannot safely resolve:
            //   - Escaped/encoded keys in double-quoted strings ("u\u0073es")
            //   - Flow-style sequence steps (- { uses: ... }, - { run: ... })
            //   - YAML aliases/anchors on run:, uses:, or permissions: values
            //
            // All-zero SHAs and v0.0.0 placeholder pins are rejected.
            // opts.requirePermissions (default true) — workflow files require a top-level
            // permissions: key; action manifests do not support it and must pass false.
            function validateWorkflowContent(content, filename, opts) {
              const requirePermissions = !opts || opts.requirePermissions !== false;
              const errs = [];
              const EXPR_OPEN = '$' + '{{';

              // 1. Top-level permissions key required (workflows only; not action manifests).
              if (requirePermissions) {
                if (!/^(?:"permissions"|'permissions'|permissions):/m.test(content)) {
                  errs.push(filename + ': missing top-level "permissions:" key');
                }

                // 1b. Top-level permissions alias check.
                if (/^(?:"permissions"|'permissions'|permissions):[ \t]+\*/m.test(content)) {
                  errs.push(filename + ': YAML alias for top-level "permissions:" value is not supported — inline the permissions map');
                }
              }

              // 2. Line-by-line scan.
              // inBlock: currently inside a block scalar
              // blockIndent: indent of the key that opened the block scalar
              // blockIsRun: the block belongs to a run: key (check expressions)
              const lines = content.split('\n');
              let inBlock = false;
              let blockIndent = -1;
              let blockIsRun = false;

              for (let i = 0; i < lines.length; i++) {
                const line = lines[i];
                const rawIndent = (line.match(/^([ \t]*)/) || ['', ''])[1].length;

                // ── Inside a block scalar ────────────────────────────────────────
                if (inBlock) {
                  if (line.trim() === '') continue;
                  if (rawIndent > blockIndent) {
                    // Content of block scalar.
                    // Only flag expression injection for run: block scalars.
                    if (blockIsRun && line.includes(EXPR_OPEN)) {
                      errs.push(filename + ':' + (i + 1) + ': run: block contains ' + EXPR_OPEN + ' }} — expressions must go through env: [fnv:' + fnv1a32(line.trim()) + ']');
                    }
                    continue;
                  }
                  // Indent at or below the block key — exit block scalar.
                  inBlock = false;
                  blockIndent = -1;
                  blockIsRun = false;
                  // Fall through to process this line as structural YAML.
                }

                // ── Escaped/encoded double-quoted key — fail closed ───────────────
                // A double-quoted key containing \ cannot be reliably resolved by
                // the line scanner (e.g. "u\u0073es" parses as "uses" in YAML).
                // Reject any such key at the structural position.
                if (/^[ \t]*(?:-[ \t]+)?"[^"]*\\[^"]*":/.test(line)) {
                  errs.push(filename + ':' + (i + 1) + ': escaped key in double-quoted string is not supported — use literal key names (run:, uses:, permissions:) [fnv:' + fnv1a32(line.trim()) + ']');
                  continue;
                }

                // ── Structural key with whitespace before colon — fail closed ────
                // YAML permits `key : value` but the scanner matches `key:` forms
                // only; a space before the colon silently bypasses all checks.
                // Reject any structural key (uses, run, steps — quoted or plain,
                // sequence-item or mapping) that has whitespace before the colon.
                if (/^[ \t]*(?:-[ \t]+)?(?:"(?:uses|run|steps)"|'(?:uses|run|steps)'|uses|run|steps)[ \t]+:/.test(line)) {
                  errs.push(filename + ':' + (i + 1) + ': structural key with whitespace before ":" is not supported — remove the space before the colon [fnv:' + fnv1a32(line.trim()) + ']');
                  continue;
                }

                // ── Sequence-item anchor declaration — fail closed ───────────────
                // Any line of the form `- &anchor` (with or without a mapping on
                // the same line) is rejected. A standalone `- &name` can be
                // followed on the next line by a flow-style mapping that the
                // scanner would then misread as structural YAML. The multiline
                // alias form `- *name` on subsequent steps is also unreachable
                // without first declaring such an anchor. Reject unconditionally.
                if (/^[ \t]*-[ \t]+&\S+/.test(line)) {
                  errs.push(filename + ':' + (i + 1) + ': sequence-item anchor declaration (&name) is not supported — anchors on steps may introduce flow mappings the scanner cannot safely resolve [fnv:' + fnv1a32(line.trim()) + ']');
                  continue;
                }

                // ── Flow-style sequence step — fail closed only for structural keys ─
                // `- { ... }` form cannot be safely resolved when it contains a
                // structural run: or uses: key (including quoted or escaped forms).
                // Non-step data objects like `- { os: ubuntu, node: 24 }` are
                // allowed — they cannot contain action refs or run scripts.
                // `permissions: {}` is a mapping value (not a sequence item),
                // so it is unaffected by this check entirely.
                if (/^[ \t]*-[ \t]+\{[^}]/.test(line)) {
                  const braceIdx = line.indexOf('{');
                  const flowContent = line.slice(braceIdx);
                  if (/[{,]\s*(?:"uses"|'uses'|uses|"run"|'run'|run|"[^"]*\\[^"]*")\s*:/.test(flowContent)) {
                    errs.push(filename + ':' + (i + 1) + ': flow-style step mapping with structural "run:" or "uses:" key is not supported — use block mapping style [fnv:' + fnv1a32(line.trim()) + ']');
                  }
                  continue;
                }

                // ── Flow-style steps array — fail closed ─────────────────────────
                // `steps: [...]` and `steps: [` (multiline opener) cannot be
                // safely resolved. Exception: `steps: []` is an empty array
                // with no execution and is explicitly allowed.
                // Quoted ("steps") and unquoted forms are both detected.
                const stepsFlowM = line.match(/^[ \t]*(?:"steps"|'steps'|steps):[ \t]*\[(.*)$/);
                if (stepsFlowM) {
                  const inner = stepsFlowM[1].trimStart();
                  if (!/^\]\s*(#.*)?$/.test(inner)) {
                    errs.push(filename + ':' + (i + 1) + ': flow-style "steps" array is not supported — use block-style steps list [fnv:' + fnv1a32(line.trim()) + ']');
                  }
                  continue;
                }

                // ── Any block scalar key detection (| or >) ──────────────────────
                // Matches quoted ("key", 'key') and unquoted (key) key names,
                // with optional sequence-item prefix (- ), followed by a block
                // indicator (| or > with optional explicit-indent/chomp modifiers).
                // YAML block scalar header forms: |  |2  |-  |+  |2-  |2+  |-2  |+2
                // and equivalents with > (folded). Both digit-first and chomp-first
                // orderings are recognized per the YAML 1.2 spec.
                // Groups: [1]=indent [2]=full-key [3]=dq-content [4]=sq-content [5]=unquoted [6]=indicator
                const blockM = line.match(/^([ \t]*)(?:-[ \t]+)?("([^"]*)"|'([^']*)'|([\w-]+)):[ \t]*([|>](?:[1-9][-+]?|[-+][1-9]?)?)[ \t]*(?:#.*)?$/);
                if (blockM) {
                  const keyName = blockM[3] !== undefined ? blockM[3] : (blockM[4] !== undefined ? blockM[4] : (blockM[5] || ''));
                  if (keyName === 'uses') {
                    errs.push(filename + ':' + (i + 1) + ': uses: block scalar is not supported — action refs must be inline and pinned to an immutable SHA [fnv:' + fnv1a32(line.trim()) + ']');
                    continue;
                  }
                  inBlock = true;
                  blockIndent = blockM[1].length;
                  blockIsRun = (keyName === 'run');
                  continue;
                }

                // ── Inline run: value (no block indicator) ───────────────────────
                // Handles mapping form and sequence-item form; quoted and unquoted key.
                // A run: &anchor | line (anchor before block indicator) falls here
                // because blockM cannot match it; the & causes the alias check below.
                const inlineRunM = line.match(/^[ \t]*(?:-[ \t]+)?(?:"run"|'run'|run):[ \t]+(.*)$/);
                if (inlineRunM) {
                  const runVal = inlineRunM[1].trimStart();
                  // A YAML alias is *name; an anchor is &name (non-whitespace after &).
                  // Ordinary shell & like 'echo "R&D build"' does not start with * or &word.
                  if (runVal[0] === '*' || /^&\S/.test(runVal)) {
                    errs.push(filename + ':' + (i + 1) + ': YAML alias/anchor in "run:" value is not supported — inline the run script [fnv:' + fnv1a32(line.trim()) + ']');
                    continue;
                  }
                  if (inlineRunM[1].includes(EXPR_OPEN)) {
                    errs.push(filename + ':' + (i + 1) + ': run: value contains ' + EXPR_OPEN + ' }} — expressions must go through env: [fnv:' + fnv1a32(line.trim()) + ']');
                  }
                  continue;
                }

                // ── uses: key detection ──────────────────────────────────────────
                // Handles mapping form and sequence-item form; quoted and unquoted key.
                const usesM = line.match(/^[ \t]+(?:-[ \t]+)?(?:"uses"|'uses'|uses):[ \t]+(.+)$/);
                if (!usesM) continue;

                // Parse the action ref — handle quoted scalar with comment outside quotes.
                const rawVal = usesM[1].trim();

                // Reject YAML alias/anchor in uses: value.
                // An alias is *name; an anchor is &name (non-whitespace after &).
                if (rawVal[0] === '*' || /^&\S/.test(rawVal)) {
                  errs.push(filename + ':' + (i + 1) + ': YAML alias/anchor in "uses:" value is not supported — inline the action ref [fnv:' + fnv1a32(line.trim()) + ']');
                  continue;
                }

                let ref;
                let extComment = '';

                if (rawVal[0] === '"' || rawVal[0] === "'") {
                  const q = rawVal[0];
                  const closeIdx = rawVal.indexOf(q, 1);
                  if (closeIdx !== -1) {
                    ref = rawVal.slice(1, closeIdx);
                    const rest = rawVal.slice(closeIdx + 1).trimStart();
                    if (rest[0] === '#') extComment = rest;
                  } else {
                    ref = rawVal; // malformed quote — treat as unquoted
                  }
                } else {
                  ref = rawVal;
                }

                // Local action references cannot be validated — the scanner
                // does not recursively resolve action manifests. Inline the
                // action logic or replace with an immutable remote SHA pin.
                if (ref.startsWith('./')) {
                  const short = ref.length > 80 ? ref.slice(0, 77) + '\u2026' : ref;
                  errs.push(filename + ': "uses: ' + short + '" local action reference is not supported — inline the action or use an immutable remote SHA pin');
                  continue;
                }

                // Docker refs require an immutable sha256 digest pin.
                // Mutable tags, :latest, and bare image names are rejected.
                // No # vX.Y.Z comment is required because the digest is the
                // immutable identity.
                if (ref.startsWith('docker://')) {
                  if (!/^docker:\/\/.+@sha256:[0-9a-f]{64}$/.test(ref)) {
                    const short = ref.length > 80 ? ref.slice(0, 77) + '\u2026' : ref;
                    errs.push(filename + ': "uses: ' + short + '" docker:// ref must be pinned by immutable digest (docker://<image>@sha256:<64 lowercase hex>)');
                  }
                  continue;
                }

                // Validate SHA + version comment.
                // For quoted refs, combine the unquoted value with any external comment.
                const forShaCheck = extComment ? ref + '  ' + extComment : ref;
                const shaMatch = forShaCheck.match(/@([0-9a-f]{40})[ \t]+#[ \t]+v(\d+)\.(\d+)\.(\d+)$/i);
                if (!shaMatch) {
                  const short = ref.length > 80 ? ref.slice(0, 77) + '\u2026' : ref;
                  errs.push(filename + ': "uses: ' + short + '" must be pinned to a 40-char SHA with "# vX.Y.Z" comment');
                  continue;
                }

                // Reject all-zero placeholder SHA.
                if (/^0{40}$/.test(shaMatch[1])) {
                  const short = ref.length > 60 ? ref.slice(0, 57) + '\u2026' : ref;
                  errs.push(filename + ': "uses: ' + short + '" uses a placeholder all-zero SHA — replace with the actual release SHA');
                }

                // Reject v0.0.0 placeholder version.
                if (shaMatch[2] === '0' && shaMatch[3] === '0' && shaMatch[4] === '0') {
                  const short = ref.length > 60 ? ref.slice(0, 57) + '\u2026' : ref;
                  errs.push(filename + ': "uses: ' + short + '" uses placeholder version v0.0.0 — update to the actual release version');
                }
              }

              return errs;
            }

            // Retry-After header parser — supports integer seconds and HTTP-date.
            // Returns milliseconds to wait, capped at 60000. Returns 0 for invalid
            // or non-positive values so the caller uses exponential fallback instead.
            // nowMs is injectable for testing; defaults to Date.now().
            function parseRetryAfterMs(header, nowMs) {
              if (!header) return 0;
              const secs = parseInt(header, 10);
              if (!isNaN(secs) && secs > 0) return Math.min(secs * 1000, 60000);
              const date = new Date(header);
              if (!isNaN(date.getTime())) {
                const ms = date.getTime() - (nowMs !== undefined ? nowMs : Date.now());
                return ms > 0 ? Math.min(ms, 60000) : 0;
              }
              return 0;
            }

            // Pure helpers for commit and file count limit checks.
            function checkCommitLimit(prCommits) {
              if (prCommits > 250) {
                return 'POLICY-INFRA: PR has ' + prCommits + ' commits — GitHub REST API caps listCommits at 250; not all commit subjects can be validated';
              }
              return null;
            }

            function checkFilesLimit(prChangedFiles) {
              if (prChangedFiles > 3000) {
                return 'POLICY-INFRA: PR has ' + prChangedFiles + ' changed files — GitHub REST API caps listFiles at 3000; not all workflow files can be validated';
              }
              return null;
            }

            // Normalize a validateWorkflowContent error string to a diff fingerprint.
            // Per-line locations are intentionally preserved so moving a grandfathered
            // violation to a different execution path is treated as a new violation.
            // Content-identifying tokens (action ref, expression text) are preserved.
            function normalizeViolationFingerprint(err) {
              return err;
            }

            // Diff head vs base violations using location-preserving fingerprints
            // with multiplicity. For each fingerprint, up to base-count head
            // violations of that fingerprint are considered pre-existing; the
            // remainder are new. Violations are returned in head-file order.
            function filterNewViolations(headErrs, baseErrs) {
              const baseCounts = new Map();
              for (const e of baseErrs) {
                const fp = normalizeViolationFingerprint(e);
                baseCounts.set(fp, (baseCounts.get(fp) || 0) + 1);
              }
              const remaining = new Map(baseCounts);
              const result = [];
              for (const e of headErrs) {
                const fp = normalizeViolationFingerprint(e);
                const rem = remaining.get(fp) || 0;
                if (rem > 0) {
                  remaining.set(fp, rem - 1);
                } else {
                  result.push(e);
                }
              }
              return result;
            }

            // Classify the status of a pull-request file for workflow scanning.
            // Returns one of four action objects:
            //   { action: 'skip' }                     — removed or unchanged; no validation
            //   { action: 'full' }                     — added or copied; full validation, no baseline
            //   { action: 'diff', basePath: string }   — modified/changed or renamed-from-workflow;
            //                                            validate head, diff against base at basePath
            //   { action: 'infra', reason: string }    — unknown status; report POLICY-INFRA
            // isWfFn must be the isWorkflowFilename predicate (injectable for testing).
            function classifyFileStatus(file, isWfFn) {
              const s = file.status;
              if (s === 'removed' || s === 'unchanged') return { action: 'skip' };
              if (s === 'added' || s === 'copied') return { action: 'full' };
              if (s === 'modified' || s === 'changed') return { action: 'diff', basePath: file.filename };
              if (s === 'renamed') {
                if (file.previous_filename &&
                    isWfFn(file.previous_filename) &&
                    policyFileKind(file.previous_filename) === policyFileKind(file.filename)) {
                  return { action: 'diff', basePath: file.previous_filename };
                }
                return { action: 'full' };
              }
              return { action: 'infra', reason: 'unknown file status "' + s + '" for ' + file.filename };
            }

            // ── Test escape ──────────────────────────────────────────────────────────
            // Set PR_POLICY_TEST=1 to extract pure functions without hitting any API.
            if (process.env.PR_POLICY_TEST === '1') {
              return {
                validateTitle,
                getJiraKey,
                validateBranch,
                validateBody,
                validateCommitSubject,
                isSyncMergeCommit,
                detectAiFooter,
                isWorkflowFilename,
                isActionManifestFilename,
                isPolicyFilename,
                policyFileKind,
                validateWorkflowContent,
                parseRetryAfterMs,
                checkCommitLimit,
                checkFilesLimit,
                normalizeViolationFingerprint,
                filterNewViolations,
                fnv1a32,
                stripHash,
                classifyFileStatus,
              };
            }

            // ── Jira API helper ──────────────────────────────────────────────────────
            // Retries on 429/5xx up to 3 times with Retry-After header support.
            // On the final attempt (attempt === 3), 429/5xx falls through to the
            // status-specific throw. Never logs secrets or response bodies.
            async function jiraGetIssue(cloudId, issueKey, email, token) {
              const https = require('https');
              const apiPath = '/ex/jira/' + cloudId + '/rest/api/3/issue/' + issueKey + '?fields=key';
              const authHeader = 'Basic ' + Buffer.from(email + ':' + token).toString('base64');
              for (let attempt = 0; attempt <= 3; attempt++) {
                const result = await new Promise(function(resolve, reject) {
                  const req = https.request({
                    hostname: 'api.atlassian.com',
                    path: apiPath,
                    method: 'GET',
                    headers: { 'Authorization': authHeader, 'Accept': 'application/json' },
                  }, function(res) {
                    const chunks = [];
                    res.on('data', function(c) { chunks.push(c); });
                    res.on('end', function() {
                      resolve({ status: res.statusCode, retryAfter: res.headers['retry-after'], body: Buffer.concat(chunks).toString('utf8') });
                    });
                  });
                  req.on('error', reject);
                  req.end();
                });
                if (result.status === 200) {
                  let parsed;
                  try { parsed = JSON.parse(result.body); } catch (_) {
                    const e = new Error('Jira API returned non-JSON'); e.isInfra = true; throw e;
                  }
                  if (parsed.key !== issueKey) throw new Error('Jira returned key "' + parsed.key + '" but expected "' + issueKey + '"');
                  return parsed;
                }
                if (result.status === 404) throw new Error('Jira issue ' + issueKey + ' not found');
                if (result.status === 401 || result.status === 403) {
                  const e = new Error('Jira auth rejected (HTTP ' + result.status + ')'); e.isInfra = true; throw e;
                }
                if ((result.status === 429 || result.status >= 500) && attempt < 3) {
                  const headerMs = parseRetryAfterMs(result.retryAfter);
                  const delayMs = headerMs > 0 ? headerMs : Math.min(2000 * (attempt + 1), 30000);
                  await new Promise(function(r) { setTimeout(r, delayMs); });
                  continue;
                }
                const e = new Error('Jira API returned HTTP ' + result.status); e.isInfra = true; throw e;
              }
            }

            // ── Main ─────────────────────────────────────────────────────────────────
            const violations = [];
            const infraCodes = [];
            let infraFailed = false;
            const MAX_ANNOTATIONS = 50;

            function addViolation(msg) { violations.push(msg); }
            function addInfra(msg) { infraCodes.push(msg); infraFailed = true; }

            const repoOwner = context.repo.owner;
            const repoName = context.repo.repo;
            const pr = context.payload.pull_request;
            const prNum = pr.number;
            const isDep = pr.user.login === 'dependabot[bot]';
            const titleTypeMatch = pr.title.match(/^([a-z]+)/);
            const titleType = titleTypeMatch ? titleTypeMatch[1] : '';

            // Pre-compute emergency-revert candidate before title validation.
            // Only a revert title that LACKS a Jira suffix triggers emergency
            // authorization; a revert title that already carries a Jira key does not.
            const hasEmergencyLabel = pr.labels.some(function(l) { return l.name === 'emergency-revert'; });
            const titleHasJira = !!getJiraKey(pr.title);
            const isEmergencyCandidate = !isDep && titleType === 'revert' && hasEmergencyLabel && !titleHasJira;

            // 1 — title convention
            for (const e of validateTitle(pr.title, isDep, isEmergencyCandidate)) addViolation('Title: ' + e);

            // 2 — branch naming (Dependabot exempt)
            for (const e of validateBranch(pr.head.ref, isDep)) addViolation('Branch: ' + e);

            // 3 — body structure (Dependabot exempt)
            for (const e of validateBody(pr.body, isDep)) addViolation('Body: ' + e);

            // 4 — AI attribution footer in title/body
            if (detectAiFooter((pr.title || '') + '\n' + (pr.body || ''))) {
              addViolation('AI attribution footer detected in PR title or body');
            }

            // 5 — commits: subject convention + AI footer
            // GitHub REST API caps listCommits at 250 total. Fail infra immediately
            // when pr.commits exceeds that limit; compare fetched count to detect
            // API truncation.
            {
              const commitLimitErr = checkCommitLimit(pr.commits);
              if (commitLimitErr) addInfra(commitLimitErr);

              let commitPage = 1;
              let commitMore = true;
              let totalFetched = 0;
              while (commitMore) {
                let resp;
                try {
                  resp = await github.rest.pulls.listCommits({ owner: repoOwner, repo: repoName, pull_number: prNum, per_page: 100, page: commitPage });
                } catch (err) {
                  addInfra('POLICY-INFRA: Failed to fetch commits (page ' + commitPage + '): ' + err.message);
                  break;
                }
                const commits = resp.data;
                const link = (resp.headers && resp.headers.link) ? resp.headers.link : '';
                totalFetched += commits.length;
                if (!link.includes('rel="next"') || commits.length === 0) commitMore = false;
                for (const c of commits) {
                  const subject = c.commit.message.split('\n')[0];
                  if (!isSyncMergeCommit(c)) {
                    for (const e of validateCommitSubject(subject)) addViolation('Commit ' + c.sha.slice(0, 8) + ': ' + e);
                  }
                  if (detectAiFooter(c.commit.message)) addViolation('Commit ' + c.sha.slice(0, 8) + ': AI attribution footer detected');
                }
                commitPage++;
              }
              if (pr.commits <= 250 && totalFetched > 0 && totalFetched !== pr.commits) {
                addInfra('POLICY-INFRA: Fetched ' + totalFetched + ' commits but PR reports ' + pr.commits + ' — API truncation suspected');
              }
            }

            // 6 — emergency-revert authorisation
            // Event timeline truncation is always POLICY-INFRA regardless of whether
            // an earlier label event was found — partial history is never trusted.
            let jiraExempt = isDep;
            let emergencyAuthFailed = false;
            if (isEmergencyCandidate) {
              try {
                let evPage = 1;
                let evMore = true;
                let latestLabelEvent = null;
                let evTruncated = false;
                while (evMore) {
                  const evResp = await github.rest.issues.listEvents({ owner: repoOwner, repo: repoName, issue_number: prNum, per_page: 100, page: evPage });
                  const evLink = (evResp.headers && evResp.headers.link) ? evResp.headers.link : '';
                  for (const ev of evResp.data) {
                    if (ev.event === 'labeled' && ev.label && ev.label.name === 'emergency-revert') latestLabelEvent = ev;
                  }
                  if (!evLink.includes('rel="next"') || evResp.data.length === 0) {
                    evMore = false;
                  } else if (evPage >= 20) {
                    evMore = false;
                    evTruncated = true;
                  }
                  evPage++;
                }
                if (evTruncated) {
                  // Partial history cannot verify the most-recent label event.
                  // An earlier maintainer event might have been superseded.
                  addInfra('POLICY-INFRA: Event timeline truncated at pagination limit — cannot verify the most-recent emergency-revert label actor; Jira key required');
                  emergencyAuthFailed = true;
                } else if (!latestLabelEvent) {
                  addViolation('emergency-revert: label present but no label event found in timeline — Jira key required');
                } else if (!latestLabelEvent.actor) {
                  addViolation('emergency-revert: label event actor is null — Jira key required');
                } else if (latestLabelEvent.actor.type === 'Bot') {
                  addViolation('emergency-revert: label applied by a bot — Jira key required');
                } else {
                  const permResp = await github.rest.repos.getCollaboratorPermissionLevel({ owner: repoOwner, repo: repoName, username: latestLabelEvent.actor.login });
                  if (permResp.data.permission === 'maintain' || permResp.data.permission === 'admin') {
                    jiraExempt = true;
                  } else {
                    addViolation('emergency-revert: label applied by user without maintain/admin permission — Jira key required');
                  }
                }
              } catch (err) {
                addInfra('POLICY-INFRA: Emergency-revert authorisation check failed: ' + err.message);
                emergencyAuthFailed = true;
              }
            }

            // 7 — Jira existence (Dependabot exempt; emergency-revert may be exempt)
            // Skip entirely when emergency auth already produced an infra error to
            // avoid a redundant credential error on a PR that has no Jira key.
            const jiraKey = isDep ? null : getJiraKey(pr.title);
            if (!jiraExempt && jiraKey && !emergencyAuthFailed) {
              const cloudId = process.env.JIRA_CLOUD_ID || '';
              const jiraEmail = process.env.JIRA_SERVICE_ACCOUNT_EMAIL || '';
              const jiraToken = process.env.JIRA_API_TOKEN || '';
              if (!cloudId || !jiraEmail || !jiraToken) {
                addInfra('POLICY-INFRA: Jira credentials missing — JIRA_CLOUD_ID, JIRA_SERVICE_ACCOUNT_EMAIL, and JIRA_API_TOKEN must all be set for human PRs');
              } else if (!/^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i.test(cloudId)) {
                addInfra('POLICY-INFRA: JIRA_CLOUD_ID is not a valid UUID');
              } else {
                try {
                  await jiraGetIssue(cloudId, jiraKey, jiraEmail, jiraToken);
                } catch (err) {
                  if (err.isInfra) addInfra('POLICY-INFRA: ' + err.message);
                  else addViolation('Jira: ' + err.message);
                }
              }
            }

            // 8 — workflow file supply-chain checks (diff-mode)
            // Only NEW violations relative to the base branch are reported.
            // Added files have no baseline and must be fully compliant.
            // Modified/renamed files are diffed: base content is fetched at
            // pr.base.sha (using previous_filename for renames). Base fetch
            // failures are POLICY-INFRA — partial history is never silently
            // grandfathered. Deleted files are skipped.
            // GitHub REST API caps listFiles at 3000.
            try {
              const filesLimitErr = checkFilesLimit(pr.changed_files);
              if (filesLimitErr) addInfra(filesLimitErr);

              let filesPage = 1;
              let filesMore = true;
              let totalFilesFetched = 0;
              while (filesMore) {
                const filesResp = await github.rest.pulls.listFiles({ owner: repoOwner, repo: repoName, pull_number: prNum, per_page: 100, page: filesPage });
                const filesLink = (filesResp.headers && filesResp.headers.link) ? filesResp.headers.link : '';
                totalFilesFetched += filesResp.data.length;
                if (!filesLink.includes('rel="next"') || filesResp.data.length === 0) filesMore = false;
                for (const file of filesResp.data) {
                  if (!isPolicyFilename(file.filename)) continue;

                  const cls = classifyFileStatus(file, isPolicyFilename);
                  if (cls.action === 'skip') continue;
                  if (cls.action === 'infra') {
                    addInfra('POLICY-INFRA: ' + cls.reason + '; skipping workflow validation');
                    continue;
                  }

                  // Fetch HEAD content via blob SHA.
                  let headContent;
                  try {
                    const blobResp = await github.rest.git.getBlob({ owner: repoOwner, repo: repoName, file_sha: file.sha });
                    const raw = blobResp.data;
                    const enc = raw.encoding === 'base64' ? 'base64' : 'utf8';
                    headContent = Buffer.from(raw.content, enc).toString('utf8');
                  } catch (blobErr) {
                    addInfra('POLICY-INFRA: Cannot fetch blob for ' + file.filename + ': ' + blobErr.message);
                    continue;
                  }

                  // Action manifests do not support top-level permissions:.
                  const wfOpts = policyFileKind(file.filename) === 'action' ? { requirePermissions: false } : {};
                  const headErrs = validateWorkflowContent(headContent, file.filename, wfOpts);

                  if (cls.action === 'full') {
                    // No baseline — added, copied, or renamed-from-non-policy path.
                    for (const e of headErrs) addViolation(e);
                  } else {
                    // diff — modified, changed, or renamed-from-policy path.
                    // Both head and base violations use file.filename so fingerprints match.
                    let baseErrs = [];
                    try {
                      const baseResp = await github.rest.repos.getContent({ owner: repoOwner, repo: repoName, path: cls.basePath, ref: pr.base.sha });
                      const baseRaw = baseResp.data;
                      const baseEnc = baseRaw.encoding === 'base64' ? 'base64' : 'utf8';
                      const baseContent = Buffer.from(baseRaw.content, baseEnc).toString('utf8');
                      baseErrs = validateWorkflowContent(baseContent, file.filename, wfOpts);
                    } catch (baseErr) {
                      addInfra('POLICY-INFRA: Cannot fetch base content for ' + file.filename + ' at ' + pr.base.sha + ': ' + baseErr.message);
                      continue;
                    }
                    for (const e of filterNewViolations(headErrs, baseErrs)) addViolation(e);
                  }
                }
                filesPage++;
              }
              if (pr.changed_files <= 3000 && totalFilesFetched > 0 && totalFilesFetched !== pr.changed_files) {
                addInfra('POLICY-INFRA: Fetched ' + totalFilesFetched + ' changed files but PR reports ' + pr.changed_files + ' — API truncation suspected');
              }
            } catch (err) {
              addInfra('POLICY-INFRA: Failed to list PR files: ' + err.message);
            }

            // 9 — emit annotations + step summary, then fail once
            // Both annotations and summary entries are capped at MAX_ANNOTATIONS
            // to prevent oversized outputs on PRs with many violations.
            const annotated = violations.slice(0, MAX_ANNOTATIONS);
            for (const msg of annotated) core.error(stripHash(msg));
            for (const msg of infraCodes.slice(0, MAX_ANNOTATIONS)) core.error(msg);
            if (violations.length > MAX_ANNOTATIONS) {
              core.warning((violations.length - MAX_ANNOTATIONS) + ' additional violation(s) suppressed (max ' + MAX_ANNOTATIONS + ' annotations)');
            }

            const totalCount = violations.length + infraCodes.length;
            const summaryParts = [totalCount === 0 ? '## PR Policy: All checks passed \u2713' : '## PR Policy: ' + totalCount + ' issue(s) found'];
            if (violations.length > 0) {
              summaryParts.push('', '### Policy violations');
              const shownV = violations.slice(0, MAX_ANNOTATIONS);
              for (const msg of shownV) summaryParts.push('- ' + stripHash(msg));
              if (violations.length > MAX_ANNOTATIONS) {
                summaryParts.push('- _...and ' + (violations.length - MAX_ANNOTATIONS) + ' more violation(s) not shown_');
              }
            }
            if (infraCodes.length > 0) {
              summaryParts.push('', '### Infrastructure failures');
              const shownI = infraCodes.slice(0, MAX_ANNOTATIONS);
              for (const msg of shownI) summaryParts.push('- ' + msg);
              if (infraCodes.length > MAX_ANNOTATIONS) {
                summaryParts.push('- _...and ' + (infraCodes.length - MAX_ANNOTATIONS) + ' more infra error(s) not shown_');
              }
            }
            await core.summary.addRaw(summaryParts.join('\n')).write();

            if (violations.length > 0 || infraFailed) {
              core.setFailed('PR policy: ' + violations.length + ' violation(s), ' + infraCodes.length + ' infrastructure error(s)');
            }