import { defineCommand } from "citty";
import consola from "consola";
import { readFileSync } from "fs";
import { fileURLToPath } from "url";
import { dirname, join } from "path";
import { ForumAgent } from "@atbb/atproto";
import { loadCliConfig } from "../lib/config.js";
import { logger } from "../lib/logger.js";

const __dirname = dirname(fileURLToPath(import.meta.url));
const PRESET_DIR = join(__dirname, "../../../../apps/web/src/styles/presets");

const PRESETS = [
  { rkey: "neobrutal-light", name: "Neobrutal Light", colorScheme: "light" as const },
  { rkey: "neobrutal-dark",  name: "Neobrutal Dark",  colorScheme: "dark"  as const },
  { rkey: "clean-light",     name: "Clean Light",     colorScheme: "light" as const },
  { rkey: "clean-dark",      name: "Clean Dark",      colorScheme: "dark"  as const },
  { rkey: "classic-bb",      name: "Classic BB",      colorScheme: "light" as const },
] as const;

/** Stable JSON string for comparison — sorted token keys, ignores ordering differences. */
function stableTokensJson(tokens: Record<string, string>): string {
  return JSON.stringify(Object.fromEntries(Object.entries(tokens).sort()));
}

/** True if the existing PDS record has the same content as the local preset. */
function isRecordCurrent(
  existing: Record<string, unknown>,
  preset: { name: string; colorScheme: string },
  tokens: Record<string, string>
): boolean {
  return (
    existing.name === preset.name &&
    existing.colorScheme === preset.colorScheme &&
    stableTokensJson(existing.tokens as Record<string, string>) === stableTokensJson(tokens)
  );
}

/**
 * Authenticate using ForumAgent and return the raw agent + DID.
 * Theme commands only need PDS_URL, FORUM_HANDLE, FORUM_PASSWORD —
 * DATABASE_URL and FORUM_DID are not required.
 */
async function authenticate(config: ReturnType<typeof loadCliConfig>) {
  const themeEnvMissing = config.missing.filter(
    (v) => v !== "DATABASE_URL" && v !== "FORUM_DID"
  );
  if (themeEnvMissing.length > 0) {
    consola.error("Missing required environment variables:");
    for (const name of themeEnvMissing) consola.error(`  - ${name}`);
    process.exit(1);
  }

  consola.start("Authenticating...");
  const forumAgent = new ForumAgent(
    config.pdsUrl, config.forumHandle, config.forumPassword, logger
  );

  try {
    await forumAgent.initialize();
  } catch (error) {
    consola.error(
      `Failed to reach PDS (${config.pdsUrl}):`,
      error instanceof Error ? error.message : String(error)
    );
    try { await forumAgent.shutdown(); } catch {}
    process.exit(1);
  }

  if (!forumAgent.isAuthenticated()) {
    const status = forumAgent.getStatus();
    consola.error(`Authentication failed: ${status.error}`);
    await forumAgent.shutdown();
    process.exit(1);
  }

  const agent = forumAgent.getAgent()!;
  const did = agent.session?.did;
  if (!did) {
    consola.error("Login succeeded but session has no DID");
    await forumAgent.shutdown();
    process.exit(1);
  }

  consola.success(`Authenticated as ${config.forumHandle} (${did})`);
  return { agent, did, forumAgent };
}

// ── bootstrap-local ──────────────────────────────────────────────────────────

const bootstrapLocalCommand = defineCommand({
  meta: {
    name: "bootstrap-local",
    description:
      "Mirror built-in preset themes to your own PDS — zero external dependencies",
  },
  args: {
    "dry-run": {
      type: "boolean",
      description: "Show what would be written without making any changes",
      default: false,
    },
  },
  async run({ args }) {
    const isDryRun = args["dry-run"];
    consola.box("atBB — Bootstrap Local Presets" + (isDryRun ? " [dry-run]" : ""));

    const config = loadCliConfig();
    const { agent, did, forumAgent } = await authenticate(config);

    consola.info(`Writing ${PRESETS.length} preset records to ${config.pdsUrl}`);
    if (isDryRun) consola.warn("Dry-run: no changes will be made.");
    consola.log("");

    const now = new Date().toISOString();
    const localUris: Array<{ rkey: string; uri: string }> = [];

    for (const preset of PRESETS) {
      const tokens = JSON.parse(
        readFileSync(join(PRESET_DIR, `${preset.rkey}.json`), "utf-8")
      ) as Record<string, string>;

      const uri = `at://${did}/space.atbb.forum.theme/${preset.rkey}`;
      localUris.push({ rkey: preset.rkey, uri });

      if (isDryRun) {
        consola.info(`  ~  ${preset.name} — would write ${uri}`);
        continue;
      }

      await agent.com.atproto.repo.putRecord({
        repo: did,
        collection: "space.atbb.forum.theme",
        rkey: preset.rkey,
        record: {
          $type: "space.atbb.forum.theme",
          name: preset.name,
          colorScheme: preset.colorScheme,
          tokens,
          createdAt: now,
          updatedAt: now,
        },
      });
      consola.success(`  ${preset.name}`);
    }

    const lightUri = localUris.find((t) => t.rkey === "neobrutal-light")!.uri;
    const darkUri  = localUris.find((t) => t.rkey === "neobrutal-dark")!.uri;
    const available = localUris.map((t) => ({ uri: t.uri }));

    consola.log("");

    // Show existing themePolicy before overwriting so operators can see what will change
    try {
      const existing = await agent.com.atproto.repo.getRecord({
        repo: did,
        collection: "space.atbb.forum.themePolicy",
        rkey: "self",
      });
      const rec = existing.data.value as Record<string, unknown>;
      const existingLight = (rec.defaultLightTheme as Record<string, string> | undefined)?.uri;
      const existingDark  = (rec.defaultDarkTheme  as Record<string, string> | undefined)?.uri;
      consola.info("Existing themePolicy:");
      consola.info(`  defaultLightTheme: ${existingLight ?? "(none)"}`);
      consola.info(`  defaultDarkTheme:  ${existingDark  ?? "(none)"}`);
    } catch {
      consola.info("No existing themePolicy — will create.");
    }

    if (isDryRun) {
      consola.info(`  ~  themePolicy — would write ${available.length} local refs`);
      consola.info(`     defaultLightTheme: ${lightUri}`);
      consola.info(`     defaultDarkTheme:  ${darkUri}`);
    } else {
      await agent.com.atproto.repo.putRecord({
        repo: did,
        collection: "space.atbb.forum.themePolicy",
        rkey: "self",
        record: {
          $type: "space.atbb.forum.themePolicy",
          availableThemes: available,
          defaultLightTheme: { uri: lightUri },
          defaultDarkTheme:  { uri: darkUri },
          allowUserChoice: true,
          updatedAt: now,
        },
      });
      consola.success("themePolicy written");
      consola.info(`  defaultLightTheme: ${lightUri}`);
      consola.info(`  defaultDarkTheme:  ${darkUri}`);
    }

    await forumAgent.shutdown();
    consola.log("");
    consola.box(
      "Done — this forum now uses only local preset refs (no atbb.space dependency).\n" +
      "You can still customize presets in the admin theme editor."
    );
  },
});

// ── publish-canonical ────────────────────────────────────────────────────────

const publishCanonicalCommand = defineCommand({
  meta: {
    name: "publish-canonical",
    description:
      "[atbb.space only] Publish built-in preset themes to the canonical PDS. " +
      "Safe to re-run — uses upsert semantics, skips unchanged presets.",
  },
  args: {
    "dry-run": {
      type: "boolean",
      description: "Show what would be written without making any changes",
      default: false,
    },
  },
  async run({ args }) {
    const isDryRun = args["dry-run"];
    consola.box("atBB — Publish Canonical Presets" + (isDryRun ? " [dry-run]" : ""));

    const config = loadCliConfig();
    const { agent, did, forumAgent } = await authenticate(config);

    consola.info(`Publishing ${PRESETS.length} presets to ${config.pdsUrl}`);
    if (isDryRun) consola.warn("Dry-run: no changes will be made.");
    consola.log("");

    const now = new Date().toISOString();
    let written = 0;
    let skipped = 0;

    for (const preset of PRESETS) {
      const tokens = JSON.parse(
        readFileSync(join(PRESET_DIR, `${preset.rkey}.json`), "utf-8")
      ) as Record<string, string>;

      // Fetch existing record to check for changes and preserve createdAt
      let existingCreatedAt: string | null = null;
      let alreadyCurrent = false;

      try {
        const res = await agent.com.atproto.repo.getRecord({
          repo: did,
          collection: "space.atbb.forum.theme",
          rkey: preset.rkey,
        });
        const existing = res.data.value as Record<string, unknown>;
        existingCreatedAt = (existing.createdAt as string) ?? null;
        if (isRecordCurrent(existing, preset, tokens)) alreadyCurrent = true;
      } catch (err: unknown) {
        // Only swallow 404 — record doesn't exist yet and will be created.
        // Re-throw anything else (network errors, auth failures, etc.).
        const status = (err as Record<string, unknown>).status;
        if (status !== 404) throw err;
      }

      if (alreadyCurrent) {
        consola.success(`${preset.name} — unchanged`);
        skipped++;
        continue;
      }

      const action = existingCreatedAt ? "updated" : "created";

      if (isDryRun) {
        consola.info(`  ~  ${preset.name} — would ${action}`);
        written++;
        continue;
      }

      const record: Record<string, unknown> = {
        $type: "space.atbb.forum.theme",
        name: preset.name,
        colorScheme: preset.colorScheme,
        tokens,
        createdAt: existingCreatedAt ?? now,
      };
      // Only set updatedAt on updates, not initial creates
      if (existingCreatedAt) record.updatedAt = now;

      await agent.com.atproto.repo.putRecord({
        repo: did,
        collection: "space.atbb.forum.theme",
        rkey: preset.rkey,
        record,
      });
      consola.success(`${preset.name} — ${action}`);
      written++;
    }

    await forumAgent.shutdown();
    consola.log("");
    consola.info(`Done. ${written} written, ${skipped} unchanged.`);
  },
});

// ── theme command group ──────────────────────────────────────────────────────

export const themeCommand = defineCommand({
  meta: {
    name: "theme",
    description: "Manage forum themes and preset publishing",
  },
  subCommands: {
    "bootstrap-local": bootstrapLocalCommand,
    "publish-canonical": publishCanonicalCommand,
  },
});