import { useState } from 'react'
import { Box, Button, Card, Typography } from '@mui/material'
import { useNavigate, useLocation } from 'react-router'
import { useQuery, useQueryClient } from '@tanstack/react-query'
import { useUnifiedResults } from '../../hooks/useUnifiedResults'
import { needService } from '../../services/needService'
import {
  FeedEmptyState,
  FeedSkeleton,
  ResultFeedHeader,
  ResultFilterBar,
  UnifiedResultFeed,
} from '../../components/results'
import { AddToShortlistDialog } from '../../components/shortlist'
import type { ResultType } from '../../domain/enums'
import type { UnifiedMatchResult } from '../../domain/unifiedResult'

type FilterSource = ResultType | 'ALL'
type SortBy = 'score' | 'rent' | 'area'

function sortResults(results: UnifiedMatchResult[], sortBy: SortBy): UnifiedMatchResult[] {
  return [...results].sort((a, b) => {
    if (sortBy === 'score') return b.matchScore - a.matchScore
    const propA = a.resultType !== 'FUTURE_AVAILABILITY' ? (a as { property: { rentPricePerSqm: number; areaSqm: number } }).property : null
    const propB = b.resultType !== 'FUTURE_AVAILABILITY' ? (b as { property: { rentPricePerSqm: number; areaSqm: number } }).property : null
    if (sortBy === 'rent') return (propA?.rentPricePerSqm ?? 0) - (propB?.rentPricePerSqm ?? 0)
    if (sortBy === 'area') return (propB?.areaSqm ?? 0) - (propA?.areaSqm ?? 0)
    return 0
  })
}

export default function Results() {
  const navigate = useNavigate()
  const location = useLocation()
  const queryClient = useQueryClient()
  const [filterSource, setFilterSource] = useState<FilterSource>('ALL')
  const [sortBy, setSortBy] = useState<SortBy>('score')

  // When coming from NeedBuilder, invalidate so the freshly created need is included
  const activeNeedIdFromNav = (location.state as { activeNeedId?: string } | null)?.activeNeedId

  const { data: needResp } = useQuery({
    queryKey: ['needs'],
    queryFn: () => needService.getAll(),
    // Refetch on mount when navigating from NeedBuilder to pick up the new need
    refetchOnMount: activeNeedIdFromNav ? 'always' : true,
    gcTime: 0,
  })

  // Prefer the ID passed from NeedBuilder; fall back to most-recently-created
  const activeNeed = needResp?.data
    ? activeNeedIdFromNav
      ? (needResp.data.find(n => n.id === activeNeedIdFromNav) ?? needResp.data[0])
      : [...needResp.data].sort((a, b) =>
          new Date(b.createdAt).getTime() - new Date(a.createdAt).getTime()
        )[0]
    : undefined

  // Ensure query cache is invalidated when a new need was just created
  if (activeNeedIdFromNav) {
    queryClient.invalidateQueries({ queryKey: ['needs'] })
  }

  const { data: results = [], isLoading } = useUnifiedResults(activeNeed?.id)

  const filtered =
    filterSource === 'ALL' ? results : results.filter(r => r.resultType === filterSource)

  const sorted = sortResults(filtered, sortBy)

  const verifiedCount = results.filter(r => r.resultType === 'VERIFIED_PORTFOLIO').length
  const externalCount = results.filter(r => r.resultType === 'EXTERNAL_MARKET').length
  const futureCount   = results.filter(r => r.resultType === 'FUTURE_AVAILABILITY').length

  return (
    <Box>
      <AddToShortlistDialog />
      <ResultFeedHeader
        total={sorted.length}
        verifiedCount={verifiedCount}
        externalCount={externalCount}
        futureCount={futureCount}
      />

      <Box sx={{ px: 3, py: 3 }}>
        {activeNeed && (
          <Card sx={{ bgcolor: '#eff6ff', p: 2, mb: 2, border: '1px solid #bfdbfe' }}>
            <Box sx={{ display: 'flex', alignItems: 'flex-start', justifyContent: 'space-between', gap: 2 }}>
              <Box>
                <Typography variant="subtitle2" sx={{ fontWeight: 700, mb: 0.5 }} color="#1e3a5f">
                  Aktive Suche: {activeNeed.companyName}
                </Typography>
                <Box sx={{ display: 'flex', flexWrap: 'wrap', gap: '4px 16px' }}>
                  <Typography variant="caption" color="text.secondary">
                    <strong>Typ:</strong> {activeNeed.assetType}
                  </Typography>
                  <Typography variant="caption" color="text.secondary">
                    <strong>Fläche:</strong> {activeNeed.requiredArea.min}–{activeNeed.requiredArea.max} m²
                  </Typography>
                  <Typography variant="caption" color="text.secondary">
                    <strong>Standort:</strong> {activeNeed.preferredLocations.join(', ')}
                  </Typography>
                  {activeNeed.budgetRange && (
                    <Typography variant="caption" color="text.secondary">
                      <strong>Budget:</strong> max. CHF {activeNeed.budgetRange.maxPerSqm}/m²
                    </Typography>
                  )}
                  {activeNeed.timing && (
                    <Typography variant="caption" color="text.secondary">
                      <strong>Bezug ab:</strong> {new Date(activeNeed.timing.earliestMoveIn).toLocaleDateString('de-CH', { month: 'long', year: 'numeric' })}
                    </Typography>
                  )}
                  {activeNeed.mustCriteriaText && activeNeed.mustCriteriaText.length > 0 && (
                    <Typography variant="caption" color="text.secondary">
                      <strong>Must-haves:</strong> {activeNeed.mustCriteriaText.slice(0, 3).join(' · ')}
                    </Typography>
                  )}
                </Box>
              </Box>
              <Button
                size="small"
                variant="text"
                onClick={() => navigate('/demand/ai-search')}
                sx={{ color: '#1e3a5f', flexShrink: 0 }}
              >
                Suche ändern
              </Button>
            </Box>
          </Card>
        )}

        <ResultFilterBar
          filterSource={filterSource}
          onFilterChange={setFilterSource}
          sortBy={sortBy}
          onSortChange={setSortBy}
        />

        {isLoading ? (
          <FeedSkeleton />
        ) : sorted.length === 0 ? (
          <FeedEmptyState filtered={filterSource !== 'ALL'} />
        ) : (
          <UnifiedResultFeed results={sorted} />
        )}
      </Box>
    </Box>
  )
}