import { useState } from 'react';
import {
  Title, Text, Card, Table, Group, Stack, Badge, Loader, Center,
  Select, TextInput, Textarea, Button, Modal, SimpleGrid, ActionIcon,
  Tooltip, Paper,
} from '@mantine/core';
import { useDisclosure } from '@mantine/hooks';
import { notifications } from '@mantine/notifications';
import {
  IconBulb, IconSearch, IconNote, IconFilter,
} from '@tabler/icons-react';
import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
import api from '../../services/api';

interface AdminIdea {
  id: string;
  title: string;
  description: string | null;
  status: string;
  createdAt: string;
  adminNote: string | null;
  orgId: string;
  orgName: string;
  userId: string;
  userEmail: string;
  userFirstName: string;
  userLastName: string;
}

const statusColor: Record<string, string> = {
  new: 'blue',
  reviewed: 'yellow',
  accepted: 'green',
  rejected: 'red',
};

const statusOptions = [
  { value: 'new', label: 'New' },
  { value: 'reviewed', label: 'Reviewed' },
  { value: 'accepted', label: 'Accepted' },
  { value: 'rejected', label: 'Rejected' },
];

function formatDate(dateStr: string | null | undefined): string {
  if (!dateStr) return '—';
  return new Date(dateStr).toLocaleDateString();
}

function formatDateTime(dateStr: string | null | undefined): string {
  if (!dateStr) return '—';
  return new Date(dateStr).toLocaleString();
}

export function AdminIdeasPage() {
  const [search, setSearch] = useState('');
  const [statusFilter, setStatusFilter] = useState<string | null>(null);
  const [selectedIdea, setSelectedIdea] = useState<AdminIdea | null>(null);
  const [detailOpened, { open: openDetail, close: closeDetail }] = useDisclosure(false);
  const [noteText, setNoteText] = useState('');
  const queryClient = useQueryClient();

  const { data: ideas, isLoading } = useQuery<AdminIdea[]>({
    queryKey: ['admin-ideas'],
    queryFn: async () => { const { data } = await api.get('/admin/ideas'); return data; },
  });

  const updateStatus = useMutation({
    mutationFn: async ({ id, status }: { id: string; status: string }) => {
      await api.put(`/admin/ideas/${id}/status`, { status });
    },
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['admin-ideas'] });
      notifications.show({ message: 'Status updated', color: 'green' });
    },
  });

  const updateNote = useMutation({
    mutationFn: async ({ id, adminNote }: { id: string; adminNote: string }) => {
      await api.put(`/admin/ideas/${id}/note`, { adminNote });
    },
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['admin-ideas'] });
      notifications.show({ message: 'Note saved', color: 'green' });
    },
  });

  const openIdeaDetail = (idea: AdminIdea) => {
    setSelectedIdea(idea);
    setNoteText(idea.adminNote || '');
    openDetail();
  };

  const handleSaveNote = () => {
    if (selectedIdea) {
      updateNote.mutate({ id: selectedIdea.id, adminNote: noteText });
    }
  };

  const filtered = (ideas || []).filter((idea) => {
    const matchesSearch = !search ||
      idea.title.toLowerCase().includes(search.toLowerCase()) ||
      idea.description?.toLowerCase().includes(search.toLowerCase()) ||
      idea.orgName.toLowerCase().includes(search.toLowerCase()) ||
      idea.userEmail.toLowerCase().includes(search.toLowerCase());
    const matchesStatus = !statusFilter || idea.status === statusFilter;
    return matchesSearch && matchesStatus;
  });

  const counts = {
    total: ideas?.length || 0,
    new: ideas?.filter(i => i.status === 'new').length || 0,
    reviewed: ideas?.filter(i => i.status === 'reviewed').length || 0,
    accepted: ideas?.filter(i => i.status === 'accepted').length || 0,
    rejected: ideas?.filter(i => i.status === 'rejected').length || 0,
  };

  if (isLoading) {
    return <Center h={400}><Loader /></Center>;
  }

  return (
    <Stack>
      <Group justify="space-between">
        <Group>
          <IconBulb size={28} />
          <Title order={2}>Idea Submissions</Title>
        </Group>
        <Badge size="lg" variant="light">{counts.total} total</Badge>
      </Group>

      {/* Summary cards */}
      <SimpleGrid cols={{ base: 2, sm: 4 }}>
        <Paper withBorder p="md" radius="md">
          <Text size="xs" c="dimmed" tt="uppercase" fw={700}>New</Text>
          <Text size="xl" fw={700} c="blue">{counts.new}</Text>
        </Paper>
        <Paper withBorder p="md" radius="md">
          <Text size="xs" c="dimmed" tt="uppercase" fw={700}>Reviewed</Text>
          <Text size="xl" fw={700} c="yellow">{counts.reviewed}</Text>
        </Paper>
        <Paper withBorder p="md" radius="md">
          <Text size="xs" c="dimmed" tt="uppercase" fw={700}>Accepted</Text>
          <Text size="xl" fw={700} c="green">{counts.accepted}</Text>
        </Paper>
        <Paper withBorder p="md" radius="md">
          <Text size="xs" c="dimmed" tt="uppercase" fw={700}>Rejected</Text>
          <Text size="xl" fw={700} c="red">{counts.rejected}</Text>
        </Paper>
      </SimpleGrid>

      {/* Filters */}
      <Group>
        <TextInput
          placeholder="Search ideas, tenants, users..."
          leftSection={<IconSearch size={16} />}
          value={search}
          onChange={(e) => setSearch(e.currentTarget.value)}
          style={{ flex: 1 }}
        />
        <Select
          placeholder="All statuses"
          leftSection={<IconFilter size={16} />}
          data={statusOptions}
          value={statusFilter}
          onChange={setStatusFilter}
          clearable
          w={160}
        />
      </Group>

      {/* Ideas table */}
      <Card withBorder p={0}>
        <Table striped highlightOnHover>
          <Table.Thead>
            <Table.Tr>
              <Table.Th>Date</Table.Th>
              <Table.Th>Tenant</Table.Th>
              <Table.Th>Submitted By</Table.Th>
              <Table.Th>Title</Table.Th>
              <Table.Th>Status</Table.Th>
              <Table.Th w={40}></Table.Th>
            </Table.Tr>
          </Table.Thead>
          <Table.Tbody>
            {filtered.length === 0 ? (
              <Table.Tr>
                <Table.Td colSpan={6}>
                  <Text ta="center" c="dimmed" py="lg">
                    {ideas?.length === 0 ? 'No ideas submitted yet' : 'No ideas match your filters'}
                  </Text>
                </Table.Td>
              </Table.Tr>
            ) : (
              filtered.map((idea) => (
                <Table.Tr
                  key={idea.id}
                  style={{ cursor: 'pointer' }}
                  onClick={() => openIdeaDetail(idea)}
                >
                  <Table.Td>
                    <Text size="xs">{formatDate(idea.createdAt)}</Text>
                  </Table.Td>
                  <Table.Td>
                    <Text size="sm" fw={500}>{idea.orgName}</Text>
                  </Table.Td>
                  <Table.Td>
                    <Text size="sm">{idea.userFirstName} {idea.userLastName}</Text>
                    <Text size="xs" c="dimmed">{idea.userEmail}</Text>
                  </Table.Td>
                  <Table.Td>
                    <Text size="sm" fw={500} lineClamp={1}>{idea.title}</Text>
                  </Table.Td>
                  <Table.Td>
                    <Badge size="sm" variant="light" color={statusColor[idea.status]}>
                      {idea.status}
                    </Badge>
                  </Table.Td>
                  <Table.Td>
                    {idea.adminNote && (
                      <Tooltip label="Has admin note">
                        <IconNote size={16} color="gray" />
                      </Tooltip>
                    )}
                  </Table.Td>
                </Table.Tr>
              ))
            )}
          </Table.Tbody>
        </Table>
      </Card>

      {/* Detail Modal */}
      <Modal
        opened={detailOpened}
        onClose={closeDetail}
        title={<Text fw={600}>Idea Detail</Text>}
        size="lg"
      >
        {selectedIdea && (
          <Stack>
            <Card withBorder>
              <SimpleGrid cols={2} spacing="xs">
                <Text size="xs" c="dimmed">Tenant</Text>
                <Text size="sm" fw={500}>{selectedIdea.orgName}</Text>
                <Text size="xs" c="dimmed">Submitted By</Text>
                <Text size="sm">{selectedIdea.userFirstName} {selectedIdea.userLastName} ({selectedIdea.userEmail})</Text>
                <Text size="xs" c="dimmed">Date</Text>
                <Text size="sm">{formatDateTime(selectedIdea.createdAt)}</Text>
              </SimpleGrid>
            </Card>

            <Card withBorder>
              <Text fw={600} mb="xs">Title</Text>
              <Text size="sm">{selectedIdea.title}</Text>
              {selectedIdea.description && (
                <>
                  <Text fw={600} mt="md" mb="xs">Description</Text>
                  <Text size="sm" style={{ whiteSpace: 'pre-wrap' }}>{selectedIdea.description}</Text>
                </>
              )}
            </Card>

            <Card withBorder>
              <Text fw={600} mb="xs">Status</Text>
              <Select
                data={statusOptions}
                value={selectedIdea.status}
                onChange={(val) => {
                  if (val && val !== selectedIdea.status) {
                    updateStatus.mutate({ id: selectedIdea.id, status: val }, {
                      onSuccess: () => {
                        setSelectedIdea({ ...selectedIdea, status: val });
                      },
                    });
                  }
                }}
                w={200}
              />
            </Card>

            <Card withBorder>
              <Group justify="space-between" mb="xs">
                <Text fw={600}>Private Admin Note</Text>
                <Text size="xs" c="dimmed">Only visible to super admins</Text>
              </Group>
              <Textarea
                placeholder="Add internal notes — sprint reference, thoughts, follow-up actions..."
                minRows={3}
                value={noteText}
                onChange={(e) => setNoteText(e.currentTarget.value)}
              />
              <Button
                size="xs"
                variant="light"
                mt="xs"
                onClick={handleSaveNote}
                loading={updateNote.isPending}
                disabled={noteText === (selectedIdea.adminNote || '')}
              >
                Save Note
              </Button>
            </Card>
          </Stack>
        )}
      </Modal>
    </Stack>
  );
}