import path from 'node:path';
import { createLearnAssistantFamilyRegistry } from './learn-assistant-family.mjs';
import { createLearnAssistantService } from './learn-assistant-service.mjs';

function handleError(res, error) {
  const status = error?.statusCode ?? 500;
  const message = error instanceof Error ? error.message : '请求失败';
  if (status >= 500) console.error('[LearnAssistant]', message);
  return res.status(status).json({ error: message });
}

async function runHandler(res, work) {
  try {
    const body = await work;
    return res.json(body);
  } catch (error) {
    return handleError(res, error);
  }
}

function readLegacyPassword(req) {
  return req.get('x-parent-pw') || req.get('x-admin-pw') || '';
}

function currentUser(req) {
  return req.currentUser ?? null;
}

export function createLearnAssistantRuntime(options = {}) {
  const dataRoot = options.dataRoot ?? path.join(options.rootDir ?? process.cwd(), 'data', 'learn-assistant');
  const service = options.service ?? createLearnAssistantService({ dataRoot });
  const familyRegistry = options.familyRegistry
    ?? createLearnAssistantFamilyRegistry({ dataRoot, seedFamilyDefaults: service.seedFamilyDefaults });
  return { dataRoot, familyRegistry, service };
}

export function attachLearnAssistantPublicRoutes(api, options = {}) {
  const { familyRegistry, service } = createLearnAssistantRuntime(options);
  const prefix = options.routePrefix ?? '/learn';

  async function withSlug(req, res, handler) {
    try {
      const family = await familyRegistry.getFamilyBySlug(req.params.slug);
      return runHandler(res, handler(family));
    } catch (error) {
      return handleError(res, error);
    }
  }

  api.get(`${prefix}/public/:slug/children`, (req, res) =>
    withSlug(req, res, (family) => service.listChildren(family.id)));

  api.get(`${prefix}/public/:slug/today`, (req, res) =>
    withSlug(req, res, (family) =>
      service.getToday(family.id, req.query.child, req.query.date)));

  api.get(`${prefix}/public/:slug/day`, (req, res) =>
    withSlug(req, res, (family) =>
      service.getDay(family.id, req.query.child, req.query.date)));

  api.post(`${prefix}/public/:slug/checkin`, (req, res) =>
    withSlug(req, res, (family) =>
      service.checkin(family.id, req.body?.id, req.body)));

  api.get(`${prefix}/public/:slug/calendar`, (req, res) =>
    withSlug(req, res, (family) =>
      service.getCalendar(family.id, req.query.child, req.query.month)));

  api.get(`${prefix}/public/:slug/growth`, (req, res) =>
    withSlug(req, res, (family) =>
      service.getGrowth(family.id, req.query.child)));

  api.get(`${prefix}/public/:slug/history`, (req, res) =>
    withSlug(req, res, (family) =>
      service.getHistory(family.id, req.query.child)));

  // legacy slug routes (tang 等旧链接)
  api.get(`${prefix}/:slug/children`, (req, res) =>
    withSlug(req, res, (family) => service.listChildren(family.id)));

  api.get(`${prefix}/:slug/today`, (req, res) =>
    withSlug(req, res, (family) =>
      service.getToday(family.id, req.query.child, req.query.date)));

  api.get(`${prefix}/:slug/day`, (req, res) =>
    withSlug(req, res, (family) =>
      service.getDay(family.id, req.query.child, req.query.date)));

  api.post(`${prefix}/:slug/checkin`, (req, res) =>
    withSlug(req, res, (family) =>
      service.checkin(family.id, req.body?.id, req.body)));

  api.get(`${prefix}/:slug/calendar`, (req, res) =>
    withSlug(req, res, (family) =>
      service.getCalendar(family.id, req.query.child, req.query.month)));

  api.get(`${prefix}/:slug/growth`, (req, res) =>
    withSlug(req, res, (family) =>
      service.getGrowth(family.id, req.query.child)));

  api.get(`${prefix}/:slug/history`, (req, res) =>
    withSlug(req, res, (family) =>
      service.getHistory(family.id, req.query.child)));

  // legacy password parent API (tang 旧家长端)
  async function withLegacyParent(req, res, handler) {
    try {
      const family = await familyRegistry.getFamilyBySlug(req.params.slug);
      await service.assertLegacyPassword(family.id, readLegacyPassword(req));
      return runHandler(res, handler(family));
    } catch (error) {
      return handleError(res, error);
    }
  }

  api.get(`${prefix}/:slug/parent/stats`, (req, res) =>
    withLegacyParent(req, res, (family) => service.parentStats(family.id)));

  api.get(`${prefix}/:slug/parent/templates`, (req, res) =>
    withLegacyParent(req, res, (family) => service.parentListTemplates(family.id)));

  api.post(`${prefix}/:slug/parent/templates`, (req, res) =>
    withLegacyParent(req, res, (family) =>
      service.parentSaveTemplate(family.id, req.body)));

  api.put(`${prefix}/:slug/parent/templates/:id`, (req, res) =>
    withLegacyParent(req, res, (family) =>
      service.parentSaveTemplate(family.id, req.body, +req.params.id)));

  api.delete(`${prefix}/:slug/parent/templates/:id`, (req, res) =>
    withLegacyParent(req, res, (family) =>
      service.parentDeleteTemplate(family.id, +req.params.id)));

  api.get(`${prefix}/:slug/parent/categories`, (req, res) =>
    withLegacyParent(req, res, (family) => service.parentListCategories(family.id)));

  api.post(`${prefix}/:slug/parent/categories`, (req, res) =>
    withLegacyParent(req, res, (family) =>
      service.parentAddCategory(family.id, req.body)));

  api.delete(`${prefix}/:slug/parent/categories/:id`, (req, res) =>
    withLegacyParent(req, res, (family) =>
      service.parentDeleteCategory(family.id, +req.params.id)));

  api.get(`${prefix}/:slug/parent/children`, (req, res) =>
    withLegacyParent(req, res, (family) => service.parentListChildren(family.id)));

  api.post(`${prefix}/:slug/parent/children`, (req, res) =>
    withLegacyParent(req, res, (family) =>
      service.parentAddChild(family.id, req.body)));

  api.delete(`${prefix}/:slug/parent/children/:id`, (req, res) =>
    withLegacyParent(req, res, (family) =>
      service.parentDeleteChild(family.id, +req.params.id)));

  api.post(`${prefix}/:slug/parent/password`, (req, res) =>
    withLegacyParent(req, res, (family) =>
      service.parentChangePassword(family.id, req.body)));

  return { familyRegistry, service };
}

export function attachLearnAssistantParentRoutes(api, options = {}) {
  const { familyRegistry, service } = createLearnAssistantRuntime(options);
  const prefix = options.routePrefix ?? '/learn';

  function requireUser(req, res) {
    const user = currentUser(req);
    if (!user?.id) {
      res.status(401).json({ error: '请先登录 Memind' });
      return null;
    }
    return user;
  }

  async function withFamily(req, res, handler) {
    const user = requireUser(req, res);
    if (!user) return null;
    try {
      const family = await familyRegistry.requireFamilyForUser(user.id, {
        displayName: user.displayName ?? user.display_name ?? user.username,
      });
      return runHandler(res, handler(family, user));
    } catch (error) {
      return handleError(res, error);
    }
  }

  api.get(`${prefix}/me/family`, async (req, res) => {
    const user = requireUser(req, res);
    if (!user) return;
    try {
      const { family, created } = await familyRegistry.getFamilyForUser(user.id, {
        displayName: user.displayName ?? user.display_name ?? user.username,
      });
      const urls = familyRegistry.familyUrls(family);
      return res.json({
        family: {
          id: family.id,
          slug: family.slug,
          name: family.name,
          members: family.members,
        },
        role: family.members.find((m) => m.userId === user.id)?.role ?? 'parent',
        urls,
        created,
      });
    } catch (error) {
      return handleError(res, error);
    }
  });

  api.post(`${prefix}/me/invite`, (req, res) =>
    withFamily(req, res, async (family, user) => {
      const invite = await familyRegistry.createInvite(user.id, {
        displayName: user.displayName ?? user.display_name ?? user.username,
      });
      const urls = familyRegistry.familyUrls(family);
      return {
        ...invite,
        joinUrl: `${urls.joinPath}${invite.token}`,
      };
    }));

  api.post(`${prefix}/me/join`, async (req, res) => {
    const user = requireUser(req, res);
    if (!user) return;
    try {
      const result = await familyRegistry.acceptInvite(user.id, req.body?.token, {
        displayName: user.displayName ?? user.display_name ?? user.username,
      });
      return res.json({
        ok: true,
        family: {
          id: result.family.id,
          slug: result.family.slug,
          name: result.family.name,
          members: result.family.members,
        },
      });
    } catch (error) {
      return handleError(res, error);
    }
  });

  api.get(`${prefix}/me/parent/stats`, (req, res) =>
    withFamily(req, res, (family) => service.parentStats(family.id)));

  api.get(`${prefix}/me/parent/templates`, (req, res) =>
    withFamily(req, res, (family) => service.parentListTemplates(family.id)));

  api.post(`${prefix}/me/parent/templates`, (req, res) =>
    withFamily(req, res, (family) =>
      service.parentSaveTemplate(family.id, req.body)));

  api.put(`${prefix}/me/parent/templates/:id`, (req, res) =>
    withFamily(req, res, (family) =>
      service.parentSaveTemplate(family.id, req.body, +req.params.id)));

  api.delete(`${prefix}/me/parent/templates/:id`, (req, res) =>
    withFamily(req, res, (family) =>
      service.parentDeleteTemplate(family.id, +req.params.id)));

  api.get(`${prefix}/me/parent/categories`, (req, res) =>
    withFamily(req, res, (family) => service.parentListCategories(family.id)));

  api.post(`${prefix}/me/parent/categories`, (req, res) =>
    withFamily(req, res, (family) =>
      service.parentAddCategory(family.id, req.body)));

  api.delete(`${prefix}/me/parent/categories/:id`, (req, res) =>
    withFamily(req, res, (family) =>
      service.parentDeleteCategory(family.id, +req.params.id)));

  api.get(`${prefix}/me/parent/children`, (req, res) =>
    withFamily(req, res, (family) => service.parentListChildren(family.id)));

  api.post(`${prefix}/me/parent/children`, (req, res) =>
    withFamily(req, res, (family) =>
      service.parentAddChild(family.id, req.body)));

  api.delete(`${prefix}/me/parent/children/:id`, (req, res) =>
    withFamily(req, res, (family) =>
      service.parentDeleteChild(family.id, +req.params.id)));

  return { familyRegistry, service };
}

/** @deprecated use attachLearnAssistantPublicRoutes + attachLearnAssistantParentRoutes */
export function attachLearnAssistantRoutes(api, options = {}) {
  const runtime = attachLearnAssistantPublicRoutes(api, options);
  attachLearnAssistantParentRoutes(api, options);
  return runtime;
}