import { Hono } from "hono";
import { nanoid } from "nanoid";
import {
  DEFAULT_TITLE,
  clampFlipMs,
  fileTooLargeMessage,
  isEffectId,
  LIMITS,
  tooManyPagesMessage,
  type CreateCatalogResponse,
  type CatalogPublic,
} from "../../shared/types";
import type { CatalogRepo } from "../catalog-repo";
import type { Env } from "../env";
import { HttpError, messages } from "../errors";
import { isJpeg } from "../magic";
import { makeQrPng } from "../qr";
import type { RateLimiter } from "../rate-limit";
import {
  deleteCatalogFiles,
  readPage,
  readQr,
  saveCatalogPages,
  saveQr,
  StorageError,
} from "../storage";

function clientIp(c: { req: { header: (name: string) => string | undefined } }): string {
  return (
    c.req.header("x-forwarded-for")?.split(",")[0]?.trim() ||
    c.req.header("x-real-ip") ||
    "127.0.0.1"
  );
}

function toPublic(row: {
  id: string;
  title: string;
  effect: CatalogPublic["effect"];
  pageCount: number;
  flipMs: number;
  createdAt: string;
}): CatalogPublic {
  return {
    id: row.id,
    title: row.title,
    effect: row.effect,
    pageCount: row.pageCount,
    flipMs: row.flipMs,
    createdAt: row.createdAt,
  };
}

async function readPageBuffers(pages: Blob[]): Promise<Buffer[]> {
  const buffers: Buffer[] = [];
  for (const file of pages) {
    if (file.size > LIMITS.maxFileBytes) {
      throw new HttpError(400, fileTooLargeMessage(file.size));
    }
    const buf = Buffer.from(await file.arrayBuffer());
    if (!isJpeg(buf)) {
      throw new HttpError(400, messages.badType);
    }
    buffers.push(buf);
  }
  return buffers;
}

function isBlobLike(value: unknown): value is Blob {
  return (
    typeof value === "object" &&
    value !== null &&
    typeof (value as Blob).arrayBuffer === "function" &&
    typeof (value as Blob).size === "number"
  );
}

function asFileArray(value: unknown): Blob[] {
  if (!value) return [];
  const list = Array.isArray(value) ? value : [value];
  return list.filter(isBlobLike);
}

export function catalogRoutes(opts: {
  env: Env;
  repo: CatalogRepo;
  limiter: RateLimiter;
}) {
  const app = new Hono();

  app.post("/catalogs", async (c) => {
    const ip = clientIp(c);
    if (!opts.limiter.check(ip)) {
      throw new HttpError(429, messages.rateLimited);
    }

    const body = await c.req.parseBody({ all: true });
    const titleRaw = typeof body.title === "string" ? body.title.trim() : "";
    const title = titleRaw || DEFAULT_TITLE;
    const effectRaw = typeof body.effect === "string" ? body.effect : "";
    if (!isEffectId(effectRaw)) {
      throw new HttpError(400, messages.badEffect);
    }
    const flipMs = clampFlipMs(body.flipMs);

    const pages = asFileArray(body.pages);
    if (pages.length < 1) {
      throw new HttpError(400, "هیچ صفحه‌ای دریافت نشد.");
    }
    if (pages.length > LIMITS.maxPages) {
      throw new HttpError(400, tooManyPagesMessage(pages.length));
    }

    const buffers = await readPageBuffers(pages);
    const id = nanoid(10);
    const deleteToken = nanoid(24);

    await saveCatalogPages(opts.env.storageDir, id, buffers);
    const viewUrl = `${opts.env.publicBaseUrl}/c/${id}`;
    const qrPng = await makeQrPng(viewUrl);
    await saveQr(opts.env.storageDir, id, qrPng);

    opts.repo.create({
      id,
      deleteToken,
      title,
      effect: effectRaw,
      pageCount: buffers.length,
      flipMs,
    });

    const payload: CreateCatalogResponse = {
      id,
      viewUrl,
      deleteUrl: `${opts.env.publicBaseUrl}/c/${id}/delete?token=${deleteToken}`,
      qrUrl: `/api/catalogs/${id}/qr`,
      doneUrl: `${opts.env.publicBaseUrl}/c/${id}/done?token=${deleteToken}`,
    };

    return c.json(payload, 201);
  });

  app.get("/catalogs/:id", (c) => {
    const row = opts.repo.getById(c.req.param("id"));
    if (!row) throw new HttpError(404, messages.notFound);
    return c.json(toPublic(row));
  });

  app.get("/catalogs/:id/pages/:n", async (c) => {
    const row = opts.repo.getById(c.req.param("id"));
    if (!row) throw new HttpError(404, messages.notFound);
    const n = Number(c.req.param("n"));
    if (!Number.isInteger(n) || n < 1 || n > row.pageCount) {
      throw new HttpError(404, messages.notFound);
    }
    try {
      const buf = await readPage(opts.env.storageDir, row.id, n);
      return new Response(buf, {
        headers: {
          "Content-Type": "image/jpeg",
          "Cache-Control": "public, max-age=31536000, immutable",
        },
      });
    } catch (err) {
      if (err instanceof StorageError) throw new HttpError(404, messages.notFound);
      throw err;
    }
  });

  app.get("/catalogs/:id/qr", async (c) => {
    const row = opts.repo.getById(c.req.param("id"));
    if (!row) throw new HttpError(404, messages.notFound);
    try {
      const buf = await readQr(opts.env.storageDir, row.id);
      return new Response(buf, {
        headers: { "Content-Type": "image/png" },
      });
    } catch (err) {
      if (err instanceof StorageError) throw new HttpError(404, messages.notFound);
      throw err;
    }
  });

  app.delete("/catalogs/:id", async (c) => {
    const token = c.req.query("token") ?? "";
    if (!token) throw new HttpError(403, messages.forbiddenDelete);
    const row = opts.repo.getById(c.req.param("id"));
    if (!row) throw new HttpError(404, messages.notFound);
    if (row.deleteToken !== token) {
      throw new HttpError(403, messages.forbiddenDelete);
    }
    opts.repo.deleteById(row.id);
    await deleteCatalogFiles(opts.env.storageDir, row.id);
    return c.body(null, 204);
  });

  return app;
}