const database = require('../config/database');
const { ROLES, SIDEBAR_PAGES, SIDEBAR_PAGE_MAP } = require('../constants/sidebarPages');
const SETTINGS_PAGE_KEY = 'settings';
const PLANNING_UPLOAD_PAGE_KEY = 'planning_upload';

function getDefaultRoleAllowed(pageKey, role) {
  return Boolean(SIDEBAR_PAGE_MAP[pageKey]?.defaultRoles?.[role]);
}

function getDefaultDepartmentAllowed(pageKey) {
  return Boolean(SIDEBAR_PAGE_MAP[pageKey]?.departmentDefaultAllowed);
}

function shouldRepairExistingPermission(pageKey, role, allowed) {
  if (pageKey === SETTINGS_PAGE_KEY && role === 'admin') {
    return !(allowed === 1 || allowed === true);
  }

  return false;
}

async function ensureSidebarRolePermissions() {
  for (const page of SIDEBAR_PAGES) {
    for (const role of ROLES) {
      const existing = await database.local.query(
        'SELECT id, page_name, allowed FROM permissions WHERE page_key = ? AND role = ? LIMIT 1',
        [page.pageKey, role]
      );

      if (existing.length > 0) {
        const shouldRepairAllowed = shouldRepairExistingPermission(page.pageKey, role, existing[0].allowed);
        const shouldRepairPageName = existing[0].page_name !== page.pageName;

        if (shouldRepairAllowed || shouldRepairPageName) {
          await database.local.query(
            'UPDATE permissions SET page_name = ?, allowed = ? WHERE id = ?',
            [
              page.pageName,
              shouldRepairAllowed ? (getDefaultRoleAllowed(page.pageKey, role) ? 1 : 0) : existing[0].allowed,
              existing[0].id,
            ]
          );
        }
        continue;
      }

      await database.local.insert('permissions', {
        page_key: page.pageKey,
        page_name: page.pageName,
        role,
        allowed: getDefaultRoleAllowed(page.pageKey, role) ? 1 : 0,
      });
    }
  }
}

async function getSidebarRolePermissions() {
  const rows = await database.local.query(
    `SELECT page_key as pageKey, page_name as pageName, role, allowed
     FROM permissions
     WHERE page_key IN (${SIDEBAR_PAGES.map(() => '?').join(', ')})`,
    SIDEBAR_PAGES.map((item) => item.pageKey)
  );

  return rows;
}

async function ensureDepartmentPagePermissions() {
  const departments = await database.local.query('SELECT id FROM departments');

  for (const department of departments) {
    const rows = await database.local.query(
      `SELECT id, page_key as pageKey, page_name as pageName
       FROM department_page_permissions
       WHERE department_id = ?`,
      [department.id]
    );

    const rowMap = rows.reduce((acc, row) => {
      acc[row.pageKey] = row;
      return acc;
    }, {});

    for (const page of SIDEBAR_PAGES) {
      const existing = rowMap[page.pageKey];
      if (existing) {
        if (existing.pageName !== page.pageName) {
          await database.local.query(
            `UPDATE department_page_permissions
             SET page_name = ?
             WHERE id = ?`,
            [page.pageName, existing.id]
          );
        }
        continue;
      }

      await database.local.insert('department_page_permissions', {
        department_id: department.id,
        page_key: page.pageKey,
        page_name: page.pageName,
        allowed: getDefaultDepartmentAllowed(page.pageKey) ? 1 : 0,
      });
    }
  }
}

async function getDepartmentPagePermissions(departmentId) {
  const rows = await database.local.query(
    `SELECT page_key as pageKey, allowed
     FROM department_page_permissions
     WHERE department_id = ?`,
    [departmentId]
  );

  const rowMap = rows.reduce((acc, row) => {
    acc[row.pageKey] = row.allowed === 1 || row.allowed === true;
    return acc;
  }, {});

  return SIDEBAR_PAGES.map((page) => ({
    pageKey: page.pageKey,
    pageName: page.pageName,
    path: page.path,
    category: page.category,
    allowed: rowMap[page.pageKey] === undefined ? getDefaultDepartmentAllowed(page.pageKey) : rowMap[page.pageKey],
  }));
}

async function saveDepartmentPagePermissions(departmentId, pagePermissions = []) {
  const normalized = SIDEBAR_PAGES.map((page) => {
    const incoming = pagePermissions.find((item) => item.pageKey === page.pageKey);
    return {
      pageKey: page.pageKey,
      pageName: page.pageName,
      allowed: incoming?.allowed !== undefined ? Boolean(incoming.allowed) : getDefaultDepartmentAllowed(page.pageKey),
    };
  });

  await database.local.query('DELETE FROM department_page_permissions WHERE department_id = ?', [departmentId]);

  for (const permission of normalized) {
    await database.local.insert('department_page_permissions', {
      department_id: departmentId,
      page_key: permission.pageKey,
      page_name: permission.pageName,
      allowed: permission.allowed ? 1 : 0,
    });
  }

  return getDepartmentPagePermissions(departmentId);
}

async function getUserPageOverrideRows(userId) {
  return database.local.query(
    `SELECT page_key as pageKey, allowed
     FROM user_page_permissions
     WHERE user_id = ?`,
    [userId]
  );
}

async function getBaseAllowedPageKeysForUser(user) {
  if (!user) {
    return [];
  }

  if (user.role === 'admin') {
    return SIDEBAR_PAGES.map((page) => page.pageKey);
  }

  const roleRows = await database.local.query(
    `SELECT page_key as pageKey, allowed
     FROM permissions
     WHERE role = ?
       AND page_key IN (${SIDEBAR_PAGES.map(() => '?').join(', ')})`,
    [user.role, ...SIDEBAR_PAGES.map((item) => item.pageKey)]
  );

  const roleAllowed = new Set(
    SIDEBAR_PAGES.filter((page) => {
      const row = roleRows.find((item) => item.pageKey === page.pageKey);
      if (!row) {
        return getDefaultRoleAllowed(page.pageKey, user.role);
      }
      return row.allowed === 1 || row.allowed === true;
    }).map((page) => page.pageKey)
  );

  if (!user.department_id) {
    if (user.role === 'admin') {
      return Array.from(roleAllowed);
    }

    return Array.from(roleAllowed).filter((pageKey) => pageKey !== PLANNING_UPLOAD_PAGE_KEY);
  }

  const departmentRows = await database.local.query(
    `SELECT page_key as pageKey, allowed
     FROM department_page_permissions
     WHERE department_id = ?`,
    [user.department_id]
  );

  if (departmentRows.length === 0) {
    return Array.from(roleAllowed).filter((pageKey) => getDefaultDepartmentAllowed(pageKey));
  }

  const departmentRowMap = departmentRows.reduce((acc, row) => {
    acc[row.pageKey] = row.allowed === 1 || row.allowed === true;
    return acc;
  }, {});

  const departmentAllowed = new Set(
    SIDEBAR_PAGES
      .filter((page) => departmentRowMap[page.pageKey] === undefined ? getDefaultDepartmentAllowed(page.pageKey) : departmentRowMap[page.pageKey])
      .map((page) => page.pageKey)
  );

  let pageKeys = Array.from(roleAllowed).filter((pageKey) => departmentAllowed.has(pageKey));

  return pageKeys;
}

async function getAllowedPageKeysForUser(user) {
  const basePageKeys = await getBaseAllowedPageKeysForUser(user);
  if (!user || user.role === 'admin') {
    return basePageKeys;
  }

  const overrideRows = await getUserPageOverrideRows(user.id);
  const userAllowed = overrideRows
    .filter((row) => row.allowed === 1 || row.allowed === true)
    .map((row) => row.pageKey);

  return Array.from(new Set([...basePageKeys, ...userAllowed]));
}

async function getUserPagePermissions(userId) {
  const users = await database.local.query(
    `SELECT id, username, name, role, department_id
     FROM users
     WHERE id = ?
     LIMIT 1`,
    [userId]
  );
  const user = users[0];
  if (!user) {
    return null;
  }

  const [basePageKeys, overrideRows] = await Promise.all([
    getBaseAllowedPageKeysForUser(user),
    getUserPageOverrideRows(userId),
  ]);
  const baseAllowed = new Set(basePageKeys);
  const overrideMap = overrideRows.reduce((acc, row) => {
    acc[row.pageKey] = row.allowed === 1 || row.allowed === true;
    return acc;
  }, {});

  return {
    user,
    permissions: SIDEBAR_PAGES.map((page) => {
      const userAllowed = overrideMap[page.pageKey] === true;
      return {
        pageKey: page.pageKey,
        pageName: page.pageName,
        path: page.path,
        category: page.category,
        baseAllowed: baseAllowed.has(page.pageKey),
        userAllowed,
        effectiveAllowed: baseAllowed.has(page.pageKey) || userAllowed,
      };
    }),
  };
}

async function saveUserPagePermissions(userId, pagePermissions = []) {
  const pageMap = new Map(SIDEBAR_PAGES.map((page) => [page.pageKey, page]));
  const normalized = pagePermissions
    .filter((item) => item?.allowed === true && pageMap.has(item.pageKey))
    .map((item) => {
      const page = pageMap.get(item.pageKey);
      return {
        pageKey: page.pageKey,
        pageName: page.pageName,
      };
    });

  const deduped = Array.from(
    normalized.reduce((acc, item) => acc.set(item.pageKey, item), new Map()).values()
  );

  await database.local.query('DELETE FROM user_page_permissions WHERE user_id = ?', [userId]);

  for (const permission of deduped) {
    await database.local.insert('user_page_permissions', {
      user_id: userId,
      page_key: permission.pageKey,
      page_name: permission.pageName,
      allowed: 1,
    });
  }

  return getUserPagePermissions(userId);
}

async function getResolvedUserWithPageAccess(userId) {
  const rows = await database.local.query(
    `SELECT
      u.id,
      u.username,
      u.name,
      u.email,
      u.role,
      u.status,
      u.department_id,
      u.avatar_url,
      u.auth_source,
      d.name as departmentName
     FROM users u
     LEFT JOIN departments d ON u.department_id = d.id
     WHERE u.id = ?
     LIMIT 1`,
    [userId]
  );

  const user = rows[0];
  if (!user) {
    return null;
  }

  const allowedPageKeys = await getAllowedPageKeysForUser(user);

  return {
    ...user,
    picture: user.avatar_url || '',
    departmentId: user.department_id || null,
    allowedPageKeys,
  };
}

module.exports = {
  SIDEBAR_PAGES,
  ensureSidebarRolePermissions,
  ensureDepartmentPagePermissions,
  getAllowedPageKeysForUser,
  getDepartmentPagePermissions,
  getResolvedUserWithPageAccess,
  getSidebarRolePermissions,
  getUserPagePermissions,
  saveDepartmentPagePermissions,
  saveUserPagePermissions,
};