import { Link, createFileRoute } from "@tanstack/react-router";
import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
import { CaretRightIcon } from "@phosphor-icons/react";
import { useEffect, useMemo, useState } from "react";
import { IoLogoGithub } from "react-icons/io5";

import type { ReposPayload, TeamSettings } from "@/lib/api";
import { AppShell, SettingsRow, SettingsSection } from "@/components/AppShell";
import { Button } from "@/components/ui/button";
import { Skeleton } from "@/components/ui/skeleton";
import { Switch } from "@/components/ui/switch";
import { Textarea } from "@/components/ui/textarea";
import { ApiError, api } from "@/lib/api";
import { RequireLogin } from "@/lib/auth-redirect";
import { useSession } from "@/lib/session";

export const Route = createFileRoute("/review")({ component: ReviewPage });

const DEFAULT_SETTINGS: TeamSettings = {
  review_draft_prs: false,
  pr_summaries: true,
  review_trace_links: true,
  review_tracing_project: null,
  org_guidelines: null,
  default_agent_model: null,
  default_agent_reasoning_effort: null,
  default_agent_subagent_model: null,
  default_agent_subagent_reasoning_effort: null,
  default_reviewer_model: null,
  default_reviewer_reasoning_effort: null,
  default_reviewer_subagent_model: null,
  default_reviewer_subagent_reasoning_effort: null,
};

function ReviewPage() {
  const session = useSession();
  const qc = useQueryClient();
  const settings = useQuery({
    queryKey: ["teamSettings"],
    queryFn: api.getTeamSettings,
    enabled: !!session.data,
  });
  const [local, setLocal] = useState<TeamSettings>(DEFAULT_SETTINGS);
  const [guidelinesDraft, setGuidelinesDraft] = useState("");
  const [error, setError] = useState<string | null>(null);

  useEffect(() => {
    if (settings.data) {
      setLocal(settings.data);
      setGuidelinesDraft(settings.data.org_guidelines ?? "");
    }
  }, [settings.data]);

  const save = useMutation({
    mutationFn: (body: TeamSettings) => api.saveTeamSettings(body),
    onSuccess: (saved) => {
      qc.setQueryData(["teamSettings"], saved);
      setError(null);
    },
    onError: (e: Error) => setError(e.message),
  });

  if (session.isLoading) {
    return (
      <main className="p-6">
        <Skeleton className="h-64 w-full" />
      </main>
    );
  }
  if (!session.data) return <RequireLogin />;

  const current: TeamSettings = local;
  const canEdit = session.data.is_admin;

  const persist = (patch: Partial<TeamSettings>) => {
    const next: TeamSettings = { ...current, ...patch };
    setLocal(next);
    if (canEdit) save.mutate(next);
  };

  const trimmedGuidelines = guidelinesDraft.trim();
  const savedGuidelines = current.org_guidelines ?? "";
  const guidelinesDirty = trimmedGuidelines !== savedGuidelines.trim();

  const saveGuidelines = () => {
    if (!canEdit) return;
    persist({ org_guidelines: trimmedGuidelines || null });
  };

  return (
    <AppShell
      user={session.data}
      title="Open SWE Review"
      description="Automatically review pull requests for bugs and issues. Runs are billed based on underlying agent usage."
    >
      <RepositoriesSection canEdit={canEdit} />

      <SettingsSection title="Rules">
        <Link
          to="/review/styles"
          className="flex items-center justify-between gap-6 px-4 py-3 hover:bg-muted/40"
        >
          <div className="flex flex-col gap-0.5">
            <span className="text-xs font-medium text-foreground">Review Style Prompts</span>
            <span className="text-xs text-muted-foreground">
              Per-repo style guides learned from past PR review feedback.
            </span>
          </div>
          <CaretRightIcon className="size-3.5 shrink-0 text-muted-foreground" />
        </Link>
      </SettingsSection>

      <SettingsSection
        title="Organization Guidelines"
        description="Org-wide instructions injected into every review, across all repositories. Repository-specific style prompts take precedence when they conflict."
      >
        <div className="flex flex-col gap-2 p-4">
          <Textarea
            className="min-h-[200px] w-full font-mono text-xs"
            value={guidelinesDraft}
            onChange={(e) => setGuidelinesDraft(e.target.value)}
            placeholder="e.g. Always flag missing input validation on new API endpoints. Prefer structured logging over print statements."
            disabled={!canEdit}
          />
          {canEdit && (
            <div className="flex items-center gap-2">
              <Button
                size="sm"
                disabled={!guidelinesDirty || save.isPending}
                onClick={saveGuidelines}
              >
                Save guidelines
              </Button>
              {guidelinesDirty && (
                <span className="text-xs text-muted-foreground">Unsaved changes</span>
              )}
            </div>
          )}
        </div>
      </SettingsSection>

      <SettingsSection title="Configuration">
        <div className="divide-y divide-border">
          <SettingsRow
            label="Review Draft PRs"
            description="Org-wide default for whether Open SWE Review runs on draft PRs. Each user can override this in Profile Settings."
            control={
              <Switch
                checked={current.review_draft_prs}
                onCheckedChange={(v) => persist({ review_draft_prs: v })}
                disabled={!canEdit}
              />
            }
          />
          <SettingsRow
            label="PR Summaries"
            description="Generate descriptions on pull requests"
            control={
              <Switch
                checked={current.pr_summaries}
                onCheckedChange={(v) => persist({ pr_summaries: v })}
                disabled={!canEdit}
              />
            }
          />
          <SettingsRow
            label="Trace Links"
            description="Include a LangSmith trace link in each review comment. Only members of your LangSmith workspace can open it."
            control={
              <Switch
                checked={current.review_trace_links}
                onCheckedChange={(v) => persist({ review_trace_links: v })}
                disabled={!canEdit}
              />
            }
          />
        </div>
      </SettingsSection>

      {!canEdit && (
        <p className="text-xs text-muted-foreground">
          These settings are read-only. Ask a workspace admin to change them.
        </p>
      )}

      {error && <p className="text-xs text-destructive">{error}</p>}
    </AppShell>
  );
}

function RepositoriesSection({ canEdit: _canEdit }: { canEdit: boolean }) {
  const repos = useQuery<ReposPayload>({
    queryKey: ["repos"],
    queryFn: async () => {
      try {
        return await api.repos();
      } catch (e) {
        if (e instanceof ApiError && e.status === 401)
          return { installations: [], repositories: [] };
        throw e;
      }
    },
  });

  const enabled = useQuery({
    queryKey: ["enabledReviewRepos"],
    queryFn: api.listEnabledReviewRepos,
  });

  const enabledSet = useMemo(
    () => new Set(enabled.data?.repos ?? []),
    [enabled.data?.repos],
  );

  const grouped = useMemo(() => {
    const byOwner = new Map<string, Array<{ full_name: string; private: boolean }>>();
    for (const r of repos.data?.repositories ?? []) {
      const [owner] = r.full_name.split("/");
      if (!owner) continue;
      const arr = byOwner.get(owner) ?? [];
      arr.push(r);
      byOwner.set(owner, arr);
    }
    return Array.from(byOwner.entries()).sort(([a], [b]) => a.localeCompare(b));
  }, [repos.data?.repositories]);

  const loading = repos.isLoading || enabled.isLoading;

  return (
    <SettingsSection
      title="Repositories"
      description="Source-control installations. Click into one to enable repos for automatic review."
    >
      <div className="divide-y divide-border">
        {loading && (
          <div className="p-4">
            <Skeleton className="h-16 w-full" />
          </div>
        )}
        {!loading && grouped.length === 0 && (
          <p className="px-4 py-3 text-xs text-muted-foreground">
            No GitHub App installations found. Install the open-swe GitHub App on an
            account or org to manage repos here.
          </p>
        )}
        {grouped.map(([owner, list]) => {
          const enabledCount = list.filter((r) => enabledSet.has(r.full_name)).length;
          return (
            <Link
              key={owner}
              to="/review/repositories/$owner"
              params={{ owner }}
              className="flex items-center justify-between gap-4 px-4 py-3 hover:bg-muted/40"
            >
              <div className="flex items-center gap-3">
                <IoLogoGithub className="size-5 shrink-0 text-muted-foreground" />
                <div className="flex flex-col gap-0.5">
                  <div className="flex items-center gap-2 text-xs">
                    <span className="font-medium text-foreground">{owner}</span>
                  </div>
                  <span className="text-xs text-muted-foreground">GitHub</span>
                </div>
              </div>
              <div className="flex items-center gap-2 text-xs text-muted-foreground">
                <span>
                  {enabledCount}/{list.length} Repositories Enabled
                </span>
                <CaretRightIcon className="size-3.5" />
              </div>
            </Link>
          );
        })}
      </div>
    </SettingsSection>
  );
}