import { FC, ReactElement, useState, useEffect, useCallback } from 'react';
import { Button } from '@imphnen-frontend-service/ui/atoms';
import { createFileRoute, Link, useNavigate } from '@tanstack/react-router';
import {
  useTeams,
  useJoinTeam,
  useMyTeams,
  ETeamVisibility,
  joinTeamSchema,
  TJoinTeamForm } from '@imphnen-frontend-service/service';
import { useForm } from 'react-hook-form';
import { zodResolver } from '@hookform/resolvers/zod';
import { CitySelect } from '../../../components/city-select';
import { Icon } from '@iconify/react';

export const Route = createFileRoute('/_authenticated/teams/browse')({
  component: BrowseTeamsPage,
})

const DEFAULT_PER_PAGE = 12;
const PER_PAGE_OPTIONS = [6, 12, 24, 48];

const TEAM_FEATURES_DEADLINE = new Date('2025-11-30T16:59:00Z');

const MEMBER_FILTER_OPTIONS = [
  { label: 'All Teams', value: '', minMembers: undefined, maxMembers: undefined },
  { label: 'Looking for Members (1-4)', value: 'looking', minMembers: 1, maxMembers: 4 },
  { label: '1 Member', value: '1', minMembers: 1, maxMembers: 1 },
  { label: '2 Members', value: '2', minMembers: 2, maxMembers: 2 },
  { label: '3 Members', value: '3', minMembers: 3, maxMembers: 3 },
  { label: '4 Members', value: '4', minMembers: 4, maxMembers: 4 },
  { label: '5 Members (Full)', value: '5', minMembers: 5, maxMembers: 5 },
];

const SUBMISSION_FILTER_OPTIONS = [
  { label: 'All Teams', value: '' },
  { label: 'Submitted', value: 'true' },
  { label: 'Not Submitted', value: 'false' },
];

const TeamCardSkeleton: FC = () => (
  <div className="bg-white dark:bg-gray-900 rounded-lg shadow-md overflow-hidden flex flex-col border dark:border-gray-800 animate-pulse">
    <div className="w-full aspect-3/1 bg-gray-200 dark:bg-gray-700" />
    <div className="p-6 flex flex-col flex-1">
      <div className="flex items-center space-x-3 mb-3">
        <div className="w-12 h-12 rounded-full bg-gray-200 dark:bg-gray-700" />
        <div className="flex-1">
          <div className="h-5 w-32 bg-gray-200 dark:bg-gray-700 rounded mb-2" />
          <div className="h-4 w-48 bg-gray-200 dark:bg-gray-700 rounded" />
        </div>
      </div>
      <div className="space-y-2 mb-4 flex-1">
        <div className="h-4 w-full bg-gray-200 dark:bg-gray-700 rounded" />
        <div className="h-4 w-5/6 bg-gray-200 dark:bg-gray-700 rounded" />
        <div className="h-4 w-4/6 bg-gray-200 dark:bg-gray-700 rounded" />
      </div>
      <div className="space-y-3 mt-auto">
        <div className="h-10 w-full bg-gray-200 dark:bg-gray-700 rounded" />
        <div className="h-10 w-full bg-gray-200 dark:bg-gray-700 rounded" />
      </div>
    </div>
  </div>
);

const BrowseTeamsPage: FC = (): ReactElement => {
  const navigate = useNavigate();
  const searchParams = new URLSearchParams(globalThis.location.search);
  const setSearchParams = (newParams: URLSearchParams, opts?: { replace?: boolean }) => {
    const url = new URL(globalThis.location.href);
    url.search = newParams.toString();
    if (opts?.replace) {
      globalThis.history.replaceState(null, '', url.toString());
    } else {
      globalThis.history.pushState(null, '', url.toString());
    }
  };

  const isTeamFeaturesClosed = new Date() >= TEAM_FEATURES_DEADLINE;

  const initialPage = parseInt(searchParams.get('page') || '1', 10);
  const initialPerPage = parseInt(
    searchParams.get('per_page') || String(DEFAULT_PER_PAGE),
    10
  );
  const initialSearch = searchParams.get('search') || '';
  const initialCity = searchParams.get('city') || '';
  const initialMembers = searchParams.get('members') || '';
  const initialSubmission = searchParams.get('submission') || '';

  const [searchTerm, setSearchTerm] = useState(initialSearch);
  const [debouncedSearch, setDebouncedSearch] = useState(initialSearch);
  const [selectedCity, setSelectedCity] = useState(initialCity);
  const [selectedMembers, setSelectedMembers] = useState(initialMembers);
  const [selectedSubmission, setSelectedSubmission] = useState(initialSubmission);
  const [selectedTeamId, setSelectedTeamId] = useState<string | null>(null);
  const [showJoinModal, setShowJoinModal] = useState(false);
  const [currentPage, setCurrentPage] = useState(
    PER_PAGE_OPTIONS.includes(initialPerPage) ? initialPage : 1
  );
  const [perPage, setPerPage] = useState(
    PER_PAGE_OPTIONS.includes(initialPerPage) ? initialPerPage : DEFAULT_PER_PAGE
  );

  const updateUrlParams = useCallback(
    (params: {
      page?: number;
      per_page?: number;
      search?: string;
      city?: string;
      members?: string;
      submission?: string;
    }) => {
      const newParams = new URLSearchParams(searchParams);

      if (params.page !== undefined) {
        if (params.page === 1) {
          newParams.delete('page');
        } else {
          newParams.set('page', String(params.page));
        }
      }

      if (params.per_page !== undefined) {
        if (params.per_page === DEFAULT_PER_PAGE) {
          newParams.delete('per_page');
        } else {
          newParams.set('per_page', String(params.per_page));
        }
      }

      if (params.search !== undefined) {
        if (params.search === '') {
          newParams.delete('search');
        } else {
          newParams.set('search', params.search);
        }
      }

      if (params.city !== undefined) {
        if (params.city === '') {
          newParams.delete('city');
        } else {
          newParams.set('city', params.city);
        }
      }

      if (params.members !== undefined) {
        if (params.members === '') {
          newParams.delete('members');
        } else {
          newParams.set('members', params.members);
        }
      }

      if (params.submission !== undefined) {
        if (params.submission === '') {
          newParams.delete('submission');
        } else {
          newParams.set('submission', params.submission);
        }
      }

      setSearchParams(newParams, { replace: true });
    },
    [searchParams, setSearchParams]
  );

  useEffect(() => {
    const timer = setTimeout(() => {
      setDebouncedSearch(searchTerm);
      if (searchTerm !== debouncedSearch) {
        setCurrentPage(1);
        updateUrlParams({ search: searchTerm, page: 1 });
      }
    }, 300);
    return () => clearTimeout(timer);
  }, [searchTerm]);

  useEffect(() => {
    if (selectedCity !== initialCity) {
      setCurrentPage(1);
      updateUrlParams({ city: selectedCity, page: 1 });
    }
  }, [selectedCity]);

  const memberFilter = MEMBER_FILTER_OPTIONS.find(
    (opt) => opt.value === selectedMembers
  );

  const hasSubmissionFilter = selectedSubmission === 'true' ? true : selectedSubmission === 'false' ? false : undefined;

  const {
    data: teamsData,
    isLoading,
    isFetching,
  } = useTeams({
    page: currentPage,
    limit: perPage,
    search: debouncedSearch,
    city: selectedCity || undefined,
    visibility: ETeamVisibility.PUBLIC,
    minMembers: memberFilter?.minMembers,
    maxMembers: memberFilter?.maxMembers,
    hasSubmission: hasSubmissionFilter,
  });

  const { data: myTeamsData } = useMyTeams();
  const { mutateAsync: joinTeam, isPending: isJoining } = useJoinTeam();

  const form = useForm<TJoinTeamForm>({
    resolver: zodResolver(joinTeamSchema),
    mode: 'all',
  });

  const teams = teamsData?.teams || [];
  const totalPages = teamsData?.totalPages || 1;
  const total = teamsData?.total || 0;
  const myTeams = myTeamsData?.data || [];

  const isMyTeam = (teamId: string) => {
    return myTeams.some((team: any) => team.id === teamId);
  };

  const handleJoinRequest = (teamId: string) => {
    setSelectedTeamId(teamId);
    setShowJoinModal(true);
  };

  const onSubmit = form.handleSubmit(async (data) => {
    if (!selectedTeamId) return;

    try {
      await joinTeam({ teamId: selectedTeamId, data });
      setShowJoinModal(false);
      form.reset();
      setSelectedTeamId(null);
    } catch (error) {
      console.error('Failed to send join request:', error);
    }
  });

  const getPageNumbers = () => {
    const pages: (number | string)[] = [];
    const maxVisible = 5;

    if (totalPages <= maxVisible + 2) {
      for (let i = 1; i <= totalPages; i++) {
        pages.push(i);
      }
    } else {
      pages.push(1);

      if (currentPage > 3) {
        pages.push('...');
      }

      const start = Math.max(2, currentPage - 1);
      const end = Math.min(totalPages - 1, currentPage + 1);

      for (let i = start; i <= end; i++) {
        pages.push(i);
      }

      if (currentPage < totalPages - 2) {
        pages.push('...');
      }

      pages.push(totalPages);
    }

    return pages;
  };

  return (
    <div className="min-h-screen bg-gray-50 dark:bg-gray-950">
      <div className="bg-white dark:bg-gray-900 border-b dark:border-gray-800">
        <div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8 py-6">
          <div className="flex items-center justify-between">
            <div>
              <h1 className="text-3xl font-bold text-gray-900 dark:text-white">
                Browse Teams
              </h1>
              <p className="text-gray-600 dark:text-gray-400 mt-1">
                Find and join teams looking for members
              </p>
            </div>
            <Link to="/dashboard" className="hidden md:block">
              <Button variant="secondary">Back to Dashboard</Button>
            </Link>
          </div>
        </div>
      </div>

      <div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8 py-6">
        <div className="bg-white dark:bg-gray-900 p-6 rounded-lg shadow-sm mb-6 border dark:border-gray-800">
          <div className="grid gap-4 md:grid-cols-2 lg:grid-cols-4">
            <div>
              <label className="block text-sm font-medium text-gray-700 dark:text-gray-300 mb-2">
                Search Teams
              </label>
              <input
                type="text"
                placeholder="Search by team name..."
                value={searchTerm}
                onChange={(e) => setSearchTerm(e.target.value)}
                className="w-full h-[42px] px-3 border border-gray-300 dark:border-gray-700 rounded-md focus:ring-2 focus:ring-blue-500 focus:border-transparent bg-white dark:bg-gray-800 text-gray-900 dark:text-white placeholder:text-gray-400 dark:placeholder:text-gray-500"
              />
            </div>
            <div>
              <label className="block text-sm font-medium text-gray-700 dark:text-gray-300 mb-2">
                Filter by City
              </label>
              <CitySelect
                value={selectedCity}
                onChange={setSelectedCity}
                placeholder="All Cities (search to filter...)"
              />
            </div>
            <div>
              <label className="block text-sm font-medium text-gray-700 dark:text-gray-300 mb-2">
                Filter by Members
              </label>
              <select
                value={selectedMembers}
                onChange={(e) => {
                  setSelectedMembers(e.target.value);
                  setCurrentPage(1);
                  updateUrlParams({ members: e.target.value, page: 1 });
                }}
                className="w-full h-[42px] px-3 border border-gray-300 dark:border-gray-700 rounded-md focus:ring-2 focus:ring-blue-500 focus:border-transparent bg-white dark:bg-gray-800 text-gray-900 dark:text-white"
              >
                {MEMBER_FILTER_OPTIONS.map((option) => (
                  <option key={option.value} value={option.value}>
                    {option.label}
                  </option>
                ))}
              </select>
            </div>
            <div>
              <label className="block text-sm font-medium text-gray-700 dark:text-gray-300 mb-2">
                Submission Status
              </label>
              <select
                value={selectedSubmission}
                onChange={(e) => {
                  setSelectedSubmission(e.target.value);
                  setCurrentPage(1);
                  updateUrlParams({ submission: e.target.value, page: 1 });
                }}
                className="w-full h-[42px] px-3 border border-gray-300 dark:border-gray-700 rounded-md focus:ring-2 focus:ring-blue-500 focus:border-transparent bg-white dark:bg-gray-800 text-gray-900 dark:text-white"
              >
                {SUBMISSION_FILTER_OPTIONS.map((option) => (
                  <option key={option.value} value={option.value}>
                    {option.label}
                  </option>
                ))}
              </select>
            </div>
          </div>
        </div>

        {!isLoading && total > 0 && (
          <div className="mb-4 text-sm text-gray-600 dark:text-gray-400">
            Showing {(currentPage - 1) * perPage + 1}-
            {Math.min(currentPage * perPage, total)} of {total} teams
          </div>
        )}

        {isLoading || isFetching ? (
          <div className="grid gap-6 md:grid-cols-2 xl:grid-cols-3">
            {Array.from({ length: perPage }).map((_, index) => (
              <TeamCardSkeleton key={index} />
            ))}
          </div>
        ) : teams.length === 0 ? (
          <div className="bg-white dark:bg-gray-900 rounded-lg shadow-sm p-12 text-center">
            <p className="text-gray-600 dark:text-gray-400 text-lg">
              No teams found
            </p>
            <p className="text-gray-500 dark:text-gray-500 mt-2">
              Try adjusting your filters
            </p>
          </div>
        ) : (
          <>
            <div className="grid gap-6 md:grid-cols-2 xl:grid-cols-3">
              {teams.map((team: any) => (
                <div
                  key={team.id}
                  className="bg-white dark:bg-gray-900 rounded-lg shadow-md overflow-hidden hover:shadow-lg transition-shadow flex flex-col border dark:border-gray-800"
                >
                  <img
                    src={team.banner || '/images/banner-imphnen.webp'}
                    alt={team.name}
                    className="w-full aspect-3/1 object-cover"
                  />
                  <div className="p-6 flex flex-col flex-1">
                    <div className="flex items-center space-x-3 mb-3">
                      {team.logo ? (
                        <img
                          src={team.logo}
                          alt={team.name}
                          className="w-12 h-12 rounded-full object-cover"
                        />
                      ) : (
                        <div className="w-12 h-12 rounded-full bg-gray-200 dark:bg-gray-700 flex items-center justify-center">
                          <span className="text-gray-500 dark:text-gray-300 text-xl">
                            <Icon icon="mdi:account-group" />
                          </span>
                        </div>
                      )}
                      <div className="flex-1 min-w-0">
                        <h3 className="text-lg font-bold text-gray-900 dark:text-white line-clamp-1 leading-tight">
                          {team.name}
                        </h3>
                        <div className="text-sm font-sans text-gray-600 dark:text-gray-400 flex items-center gap-2 mt-1">
                          {team.has_submission && (
                            <span className="inline-flex items-center gap-1 px-2 py-0.5 rounded text-xs font-medium bg-green-100 dark:bg-green-900/30 text-green-700 dark:text-green-400 shrink-0">
                              <Icon icon="mdi:check-circle" className="text-sm" />
                              Submitted
                            </span>
                          )}
                          <p className="truncate flex-1 min-w-0 flex items-center gap-x-1">
                            <Icon icon="mdi:map-marker" />{' '}
                            <span>{team.city}</span>
                          </p>
                          <p className="whitespace-nowrap shrink-0 flex items-center gap-x-1">
                            <Icon icon="mdi:account-group" />{' '}
                            {team.member_count || 0} members
                          </p>
                        </div>
                      </div>
                    </div>
                    <p className="text-gray-600 dark:text-gray-300 text-sm mb-4 line-clamp-3 font-sans flex-1">
                      {team.description}
                    </p>
                    <div className="space-y-3 mt-auto">
                      {(team.member_count || 0) === 1 && !team.has_submission && (
                        <div className="p-2 bg-amber-50 dark:bg-amber-900/20 border border-amber-200 dark:border-amber-800 rounded-lg">
                          <p className="text-xs text-amber-700 dark:text-amber-400 flex items-center gap-1">
                            <Icon icon="mdi:alert" className="text-sm shrink-0" />
                            <span>This team needs at least 2 members to submit</span>
                          </p>
                        </div>
                      )}
                      {isMyTeam(team.id) ? (
                        <Button
                          className="w-full"
                          variant="secondary"
                          onClick={() => navigate({ to: `/teams/${team.id}` })}
                        >
                          Your Team
                        </Button>
                      ) : (
                        <>
                          {myTeams.length === 0 &&
                            (team.member_count || 0) < 5 &&
                            !team.has_submission &&
                            !isTeamFeaturesClosed && (
                              <Button
                                className="w-full"
                                onClick={() => handleJoinRequest(team.id)}
                              >
                                Request to Join
                              </Button>
                            )}
                          <Button
                            className="w-full"
                            variant="secondary"
                            onClick={() => navigate({ to: `/teams/${team.id}` })}
                          >
                            View Team
                          </Button>
                        </>
                      )}
                    </div>
                  </div>
                </div>
              ))}
            </div>

            {(totalPages > 1 || total > 6) && (
              <div className="mt-8 flex flex-col sm:flex-row items-center justify-center gap-4">
                {totalPages > 1 && (
                  <div className="flex items-center gap-2">
                    <Button
                      variant="secondary"
                      onClick={() => {
                        const newPage = Math.max(1, currentPage - 1);
                        setCurrentPage(newPage);
                        updateUrlParams({ page: newPage });
                      }}
                      disabled={currentPage === 1 || isFetching}
                      className="px-3"
                    >
                      <Icon icon="mdi:chevron-left" className="text-xl" />
                    </Button>

                    <div className="flex items-center gap-1">
                      {getPageNumbers().map((page, index) =>
                        typeof page === 'string' ? (
                          <span
                            key={`ellipsis-${index}`}
                            className="px-2 text-gray-400 dark:text-gray-500"
                          >
                            ...
                          </span>
                        ) : (
                          <button
                            key={page}
                            onClick={() => {
                              setCurrentPage(page);
                              updateUrlParams({ page });
                            }}
                            disabled={isFetching}
                            className={`min-w-10 h-10 px-3 rounded-md text-sm font-medium transition-colors ${
                              currentPage === page
                                ? 'bg-blue-600 text-white'
                                : 'bg-white dark:bg-gray-800 text-gray-700 dark:text-gray-300 hover:bg-gray-100 dark:hover:bg-gray-700 border border-gray-300 dark:border-gray-600'
                            }`}
                          >
                            {page}
                          </button>
                        )
                      )}
                    </div>

                    <Button
                      variant="secondary"
                      onClick={() => {
                        const newPage = Math.min(totalPages, currentPage + 1);
                        setCurrentPage(newPage);
                        updateUrlParams({ page: newPage });
                      }}
                      disabled={currentPage === totalPages || isFetching}
                      className="px-3"
                    >
                      <Icon icon="mdi:chevron-right" className="text-xl" />
                    </Button>
                  </div>
                )}

                <div className="flex items-center gap-3">
                  {totalPages > 1 && (
                    <span className="text-sm text-gray-500 dark:text-gray-400">
                      Page {currentPage} of {totalPages}
                    </span>
                  )}

                  <div className="flex items-center gap-2">
                    <span className="text-sm text-gray-500 dark:text-gray-400">Show:</span>
                    <select
                      value={perPage}
                      onChange={(e) => {
                        const newPerPage = Number(e.target.value);
                        setPerPage(newPerPage);
                        setCurrentPage(1);
                        updateUrlParams({ per_page: newPerPage, page: 1 });
                      }}
                      className="h-10 px-3 pr-8 border border-gray-300 dark:border-gray-600 rounded-md bg-white dark:bg-gray-800 text-gray-700 dark:text-gray-300 text-sm focus:ring-2 focus:ring-blue-500 focus:border-transparent"
                    >
                      {PER_PAGE_OPTIONS.map((option) => (
                        <option key={option} value={option}>
                          {option}
                        </option>
                      ))}
                    </select>
                  </div>
                </div>
              </div>
            )}
          </>
        )}
      </div>

      {showJoinModal && (
        <div className="fixed inset-0 bg-black/30 dark:bg-black/50 backdrop-blur-sm flex items-center justify-center z-50 p-4">
          <div className="bg-white dark:bg-gray-900 rounded-lg shadow-xl max-w-md w-full p-6">
            <h2 className="text-2xl font-bold text-gray-900 dark:text-white mb-4">
              Request to Join Team
            </h2>
            <p className="text-gray-600 dark:text-gray-400 mb-6 font-sans">
              Send a message to the team leader explaining why you want to join
            </p>
            <form onSubmit={onSubmit} className="space-y-4">
              <div>
                <label className="block text-sm font-medium text-gray-700 dark:text-gray-300 mb-2">
                  Your Message
                </label>
                <textarea
                  {...form.register('message')}
                  rows={4}
                  className="w-full px-3 py-2 border border-gray-300 dark:border-gray-600 rounded-md focus:ring-2 focus:ring-blue-500 focus:border-transparent bg-white dark:bg-gray-800 text-gray-900 dark:text-white placeholder:text-gray-400 dark:placeholder:text-gray-500"
                  placeholder="Tell the team leader why you want to join their team..."
                />
                {form.formState.errors.message && (
                  <p className="text-sm text-red-500 mt-1 font-sans">
                    {form.formState.errors.message.message}
                  </p>
                )}
              </div>
              <div className="flex space-x-3">
                <Button
                  type="button"
                  variant="secondary"
                  className="flex-1"
                  onClick={() => {
                    setShowJoinModal(false);
                    form.reset();
                    setSelectedTeamId(null);
                  }}
                >
                  Cancel
                </Button>
                <Button
                  type="submit"
                  className="flex-1"
                  disabled={!form.formState.isValid || isJoining}
                >
                  {isJoining ? 'Sending...' : 'Send Request'}
                </Button>
              </div>
            </form>
          </div>
        </div>
      )}
    </div>
  );
};