import { readdir, mkdir, rm } from 'node:fs/promises';
import { join, dirname } from 'node:path';
import { createRouter } from '../../create-router';
import { getNativeResourcesDir, getGlobalResourcesDir } from '../../data-path';
import { parseFrontmatter } from '../skills/skills';

async function readResourceDirs(dir: string): Promise<Map<string, string>> {
  const result = new Map<string, string>();
  try {
    const entries = await readdir(dir, { withFileTypes: true });
    for (const entry of entries) {
      if (!entry.isDirectory()) continue;
      const resourceFile = join(dir, entry.name, 'RESOURCE.md');
      if (await Bun.file(resourceFile).exists()) {
        result.set(entry.name, resourceFile);
      }
    }
  } catch {
    // directory doesn't exist yet
  }
  return result;
}

async function readConfigFile(dir: string): Promise<Record<string, string>> {
  try {
    return await Bun.file(join(dir, 'config.json')).json();
  } catch {
    return {};
  }
}

function mergeConfig(native: Record<string, string>, global: Record<string, string>): Record<string, string> {
  const merged: Record<string, string> = {};
  for (const key of Object.keys(native)) {
    merged[key] = global[key] ?? native[key]!;
  }
  for (const key of Object.keys(global)) {
    if (!(key in merged)) merged[key] = global[key]!;
  }
  return merged;
}

function isPrivileged(role: string) {
  return role === 'Super Admin';
}

export async function readResourceConfig(name: string): Promise<Record<string, string>> {
  const nativeConfig = await readConfigFile(join(getNativeResourcesDir(), name));
  const globalConfig = await readConfigFile(join(getGlobalResourcesDir(), name));
  return mergeConfig(nativeConfig, globalConfig);
}

const CHECK_TIMEOUT_MS = 3_000;

export const resourcesRouter = createRouter();

resourcesRouter.get('/', async (ctx) => {
  const nativeResources = await readResourceDirs(getNativeResourcesDir());
  const globalResources = await readResourceDirs(getGlobalResourcesDir());

  const merged = new Map(nativeResources);
  for (const [name, path] of globalResources) merged.set(name, path);

  const resources = await Promise.all(
    Array.from(merged.entries()).map(async ([dirName, filePath]) => {
      const raw = await Bun.file(filePath).text();
      const { frontmatter } = parseFrontmatter(raw);
      const scope = globalResources.has(dirName) && !nativeResources.has(dirName) ? 'global' as const : nativeResources.has(dirName) ? 'native' as const : 'global' as const;
      const config = await readResourceConfig(dirName);
      return { dirName, name: frontmatter.name || dirName, description: frontmatter.description, scope, config };
    }),
  );

  return ctx.json(resources);
});

resourcesRouter.get('/:name', async (ctx) => {
  const name = ctx.req.param('name');

  const nativeResources = await readResourceDirs(getNativeResourcesDir());
  const globalResources = await readResourceDirs(getGlobalResourcesDir());

  const filePath = globalResources.get(name) ?? nativeResources.get(name);
  if (!filePath) return ctx.text('Not found', 404);

  const scope = globalResources.has(name) && !nativeResources.has(name) ? 'global' as const : 'native' as const;
  const raw = await Bun.file(filePath).text();
  const { frontmatter, body, rawYaml } = parseFrontmatter(raw);
  const config = await readResourceConfig(name);

  const globalConfigPath = join(getGlobalResourcesDir(), name, 'config.json');
  const chatMeta = join(dirname(filePath), 'chat', 'meta.json');
  const chatSessionId = await Bun.file(chatMeta).json().then((m: { id: string }) => m.id).catch(() => null);
  const guidePath = join(getNativeResourcesDir(), 'GUIDE.md');

  return ctx.json({
    dirName: name,
    name: frontmatter.name || name,
    description: frontmatter.description,
    scope,
    body,
    rawFrontmatter: rawYaml,
    filePath,
    config,
    configPath: globalConfigPath,
    chatSessionId,
    guidePath,
  });
});

resourcesRouter.patch('/:name/config', async (ctx) => {
  const user = ctx.get('user');
  if (!isPrivileged(user.role)) return ctx.text('Forbidden', 403);

  const name = ctx.req.param('name');
  const body = await ctx.req.json<Record<string, string | null>>();

  const globalDir = join(getGlobalResourcesDir(), name);
  await mkdir(globalDir, { recursive: true });

  const existing = await readConfigFile(globalDir);
  for (const [key, value] of Object.entries(body)) {
    if (value === null) delete existing[key];
    else existing[key] = value;
  }

  await Bun.write(join(globalDir, 'config.json'), JSON.stringify(existing, null, 2));

  const merged = await readResourceConfig(name);
  return ctx.json(merged);
});

resourcesRouter.post('/', async (ctx) => {
  const user = ctx.get('user');
  if (!isPrivileged(user.role)) return ctx.text('Forbidden', 403);

  const { name } = await ctx.req.json<{ name: string }>();
  if (!name?.trim()) return ctx.text('Name is required', 400);

  const dirName = name.trim().toLowerCase().replace(/\s+/g, '-').replace(/[^a-z0-9-]/g, '');
  if (!dirName) return ctx.text('Invalid name', 400);

  const dir = join(getGlobalResourcesDir(), dirName);
  const filePath = join(dir, 'RESOURCE.md');

  if (await Bun.file(filePath).exists()) {
    return ctx.text('Resource already exists', 409);
  }

  await mkdir(dir, { recursive: true });
  await Bun.write(filePath, `---\nname: ${name.trim()}\ndescription: \n---\n`);
  await Bun.write(join(dir, 'config.json'), JSON.stringify({ url: '', api_key: '', username: '', password: '' }, null, 2));

  return ctx.json({ name: name.trim(), dirName, filePath, scope: 'global' });
});

resourcesRouter.delete('/:name', async (ctx) => {
  const user = ctx.get('user');
  if (!isPrivileged(user.role)) return ctx.text('Forbidden', 403);

  const name = ctx.req.param('name');
  const nativeResources = await readResourceDirs(getNativeResourcesDir());

  if (nativeResources.has(name)) return ctx.text('Cannot delete native resource', 400);

  const dir = join(getGlobalResourcesDir(), name);
  const filePath = join(dir, 'RESOURCE.md');
  if (!(await Bun.file(filePath).exists())) return ctx.text('Not found', 404);

  await rm(dir, { recursive: true });
  return ctx.json({ ok: true });
});

resourcesRouter.get('/:name/chat', async (ctx) => {
  const name = ctx.req.param('name');

  const nativeResources = await readResourceDirs(getNativeResourcesDir());
  const globalResources = await readResourceDirs(getGlobalResourcesDir());

  const filePath = globalResources.get(name) ?? nativeResources.get(name);
  if (!filePath) return ctx.text('Not found', 404);

  const chatDir = join(getGlobalResourcesDir(), name, 'chat');
  const sessionId = await Bun.file(join(chatDir, 'meta.json')).json().then((m: { id: string }) => m.id).catch(() => null);
  const messages = await Bun.file(join(chatDir, 'messages.json')).json().catch(() => []);

  return ctx.json({ sessionId, messages });
});

resourcesRouter.put('/:name/chat', async (ctx) => {
  const user = ctx.get('user');
  if (!isPrivileged(user.role)) return ctx.text('Forbidden', 403);

  const name = ctx.req.param('name');
  const { sessionId, messages } = await ctx.req.json<{ sessionId: string; messages: unknown[] }>();

  const chatDir = join(getGlobalResourcesDir(), name, 'chat');
  await mkdir(chatDir, { recursive: true });
  await Bun.write(join(chatDir, 'messages.json'), JSON.stringify(messages));
  if (sessionId) await Bun.write(join(chatDir, 'meta.json'), JSON.stringify({ id: sessionId }));

  return ctx.json({ ok: true });
});

resourcesRouter.delete('/:name/chat', async (ctx) => {
  const user = ctx.get('user');
  if (!isPrivileged(user.role)) return ctx.text('Forbidden', 403);

  const name = ctx.req.param('name');
  const chatDir = join(getGlobalResourcesDir(), name, 'chat');
  await rm(chatDir, { recursive: true, force: true });

  return ctx.json({ ok: true });
});

resourcesRouter.post('/:name/ping', async (ctx) => {
  const name = ctx.req.param('name');
  const body = await ctx.req.json<{ url?: string }>().catch((): { url?: string } => ({}));
  const config = await readResourceConfig(name);

  const url = body.url ?? config.url;
  if (!url) return ctx.json({ error: 'No URL configured' }, 400);

  try {
    const start = performance.now();
    const controller = new AbortController();
    const timeout = setTimeout(() => controller.abort(), CHECK_TIMEOUT_MS);
    await fetch(url, { signal: controller.signal });
    clearTimeout(timeout);
    const latencyMs = Math.round(performance.now() - start);
    return ctx.json({ reachable: true, latencyMs });
  } catch {
    return ctx.json({ reachable: false, latencyMs: null });
  }
});