#!/usr/bin/env bash
# Validate the workflow_dispatch inputs (spec §8.2) and normalize PR references.
#
# Reads:  REVIEW_TYPE, FRONTEND_PR, BACKEND_PR, FRONTEND_REPO, BACKEND_REPO
# Writes: frontend_pr / backend_pr (numbers, empty when not in scope) to
#         $GITHUB_OUTPUT when present, else stdout.

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
# shellcheck source=lib.sh
source "$SCRIPT_DIR/lib.sh"

require_env REVIEW_TYPE FRONTEND_REPO BACKEND_REPO

# normalize_pr <raw> <expected-repo> -> prints the PR number
# Accepts a bare number or a full PR URL. Rejects URLs pointing anywhere other
# than the expected repository.
normalize_pr() {
  local raw="$1" repo="$2"
  raw="$(printf '%s' "$raw" | tr -d '[:space:]')"
  if [[ "$raw" =~ ^[0-9]+$ ]]; then
    printf '%s' "$raw"
    return 0
  fi
  if [[ "$raw" =~ ^https://github\.com/([^/]+/[^/]+)/pull/([0-9]+)(/.*)?$ ]]; then
    local url_repo="${BASH_REMATCH[1]}" num="${BASH_REMATCH[2]}"
    [ "$url_repo" = "$repo" ] || die "PR URL points at '$url_repo', expected '$repo'"
    printf '%s' "$num"
    return 0
  fi
  die "invalid PR reference '$raw' (expected a number or a $repo PR URL)"
}

frontend_pr=""
backend_pr=""

case "$REVIEW_TYPE" in
  frontend)
    [ -n "${FRONTEND_PR:-}" ] || die "review_type=frontend requires frontend_pr"
    frontend_pr="$(normalize_pr "$FRONTEND_PR" "$FRONTEND_REPO")"
    ;;
  backend)
    [ -n "${BACKEND_PR:-}" ] || die "review_type=backend requires backend_pr"
    backend_pr="$(normalize_pr "$BACKEND_PR" "$BACKEND_REPO")"
    ;;
  paired)
    [ -n "${FRONTEND_PR:-}" ] || die "review_type=paired requires frontend_pr"
    [ -n "${BACKEND_PR:-}" ] || die "review_type=paired requires backend_pr"
    frontend_pr="$(normalize_pr "$FRONTEND_PR" "$FRONTEND_REPO")"
    backend_pr="$(normalize_pr "$BACKEND_PR" "$BACKEND_REPO")"
    ;;
  *)
    die "invalid review_type '$REVIEW_TYPE' (frontend|backend|paired)"
    ;;
esac

out="${GITHUB_OUTPUT:-/dev/stdout}"
{
  printf 'frontend_pr=%s\n' "$frontend_pr"
  printf 'backend_pr=%s\n' "$backend_pr"
} >>"$out"

log "inputs valid: review_type=$REVIEW_TYPE frontend_pr=${frontend_pr:-none} backend_pr=${backend_pr:-none}"