// src/app/[locale]/admin/import/effects/import-effects-client.tsx
'use client'

import {
  AlertCircle,
  Check,
  Download,
  Loader2,
  Music,
  Package,
  Search,
  Sparkles,
  Trash2,
  X,
} from 'lucide-react'
import { useCallback, useEffect, useMemo, useState } from 'react'
import { toast } from 'sonner'
import { Badge } from '@/components/ui/badge'
import { Button } from '@/components/ui/button'
import { Input } from '@/components/ui/input'
import { cn } from '@/lib/utils'

interface EffectItem {
  id: string
  lib: string
  type: string
  revision: number
  present: boolean
  nitroExists: boolean
}

type Filter = 'all' | 'fx' | 'dance'

export function ImportEffectsClient() {
  const [searchTerm, setSearchTerm] = useState('')
  const [effects, setEffects] = useState<EffectItem[]>([])
  const [loading, setLoading] = useState(false)
  const [error, setError] = useState('')
  const [filter, setFilter] = useState<Filter>('all')
  const [selected, setSelected] = useState<Set<string>>(new Set())
  const [batchProgress, setBatchProgress] = useState<{ done: number; total: number } | null>(null)
  const [busyLib, setBusyLib] = useState<string | null>(null)

  const fetchEffects = useCallback(async (search: string) => {
    setLoading(true)
    setError('')
    try {
      const params = new URLSearchParams()
      if (search) params.set('search', search)
      const res = await fetch(`/api/admin/import/effects?${params}`)
      const data = await res.json()
      if (!res.ok) {
        setError(data.error || 'Failed to load')
        return
      }
      setEffects(data.effects || [])
      setSelected(new Set())
    } catch {
      setError('Network error')
    } finally {
      setLoading(false)
    }
  }, [])

  useEffect(() => {
    fetchEffects('')
  }, [fetchEffects])

  const visible = useMemo(
    () => effects.filter((e) => filter === 'all' || e.type === filter),
    [effects, filter],
  )
  const importable = useMemo(() => visible.filter((e) => !e.present || !e.nitroExists), [visible])
  const importedCount = useMemo(
    () => visible.filter((e) => e.present && e.nitroExists).length,
    [visible],
  )

  function toggle(lib: string) {
    setSelected((prev) => {
      const n = new Set(prev)
      if (n.has(lib)) n.delete(lib)
      else n.add(lib)
      return n
    })
  }

  function markDone(lib: string) {
    setEffects((prev) =>
      prev.map((e) => (e.lib === lib ? { ...e, present: true, nitroExists: true } : e)),
    )
  }

  async function importViaSse(items: EffectItem[]) {
    setBatchProgress({ done: 0, total: items.length })
    const res = await fetch('/api/admin/import/effects/batch', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ items, concurrency: 3 }),
    })
    if (!res.body) {
      toast.error('No response stream')
      setBatchProgress(null)
      return
    }
    const reader = res.body.getReader()
    const decoder = new TextDecoder()
    let buf = ''
    let done = 0
    let succeeded = 0
    let failed = 0
    while (true) {
      const { value, done: streamDone } = await reader.read()
      if (streamDone) break
      buf += decoder.decode(value, { stream: true })
      const parts = buf.split('\n\n')
      buf = parts.pop() ?? ''
      for (const part of parts) {
        if (!part.startsWith('data: ')) continue
        const evt = JSON.parse(part.slice(6))
        if (evt.type === 'item_progress' && evt.status === 'done') {
          done++
          succeeded++
          markDone(evt.classname)
          setBatchProgress({ done, total: items.length })
        } else if (evt.type === 'item_progress' && evt.status === 'failed') {
          done++
          failed++
          setBatchProgress({ done, total: items.length })
        } else if (evt.type === 'batch_complete') {
          succeeded = evt.succeeded
          failed = evt.failed
        }
      }
    }
    setBatchProgress(null)
    setSelected(new Set())
    if (succeeded > 0) toast.success(`${succeeded} effect(s) imported`)
    if (failed > 0) toast.error(`${failed} failed`)
  }

  async function importOne(e: EffectItem) {
    setBusyLib(e.lib)
    try {
      await importViaSse([e])
    } finally {
      setBusyLib(null)
    }
  }

  async function importSelected() {
    const items = visible.filter((e) => selected.has(e.lib) && (!e.present || !e.nitroExists))
    if (items.length === 0) return
    await importViaSse(items)
  }

  async function remove(e: EffectItem) {
    setBusyLib(e.lib)
    try {
      const res = await fetch(`/api/admin/import/effects?lib=${encodeURIComponent(e.lib)}`, {
        method: 'DELETE',
      })
      const data = await res.json()
      if (res.ok) {
        toast.success(`${e.lib} removed`)
        setEffects((prev) =>
          prev.map((x) => (x.lib === e.lib ? { ...x, present: false, nitroExists: false } : x)),
        )
      } else {
        toast.error(data.error || 'Delete failed')
      }
    } finally {
      setBusyLib(null)
    }
  }

  return (
    <div className="space-y-4">
      {/* Stats */}
      {effects.length > 0 && (
        <div className="flex items-center gap-3 flex-wrap">
          <div className="flex items-center gap-1.5 text-sm">
            <Package className="h-4 w-4 text-muted-foreground" />
            <span className="font-medium">{visible.length}</span>
            <span className="text-muted-foreground">effects</span>
          </div>
          <div className="flex items-center gap-1.5 text-sm">
            <Check className="h-4 w-4 text-[var(--admin-success)]" />
            <span className="font-medium text-[var(--admin-success)]">{importedCount}</span>
            <span className="text-muted-foreground">imported</span>
          </div>
          <div className="flex items-center gap-1.5 text-sm">
            <Download className="h-4 w-4 text-muted-foreground" />
            <span className="font-medium">{importable.length}</span>
            <span className="text-muted-foreground">available</span>
          </div>
        </div>
      )}

      {/* Search + filter */}
      <div className="flex gap-2 flex-wrap">
        <div className="relative flex-1 max-w-md">
          <Search className="absolute left-3 top-1/2 -translate-y-1/2 h-4 w-4 text-muted-foreground" />
          <Input
            placeholder="Search effects by lib / id..."
            value={searchTerm}
            onChange={(e) => setSearchTerm(e.target.value)}
            onKeyDown={(e) => {
              if (e.key === 'Enter') fetchEffects(searchTerm)
              if (e.key === 'Escape') {
                setSearchTerm('')
                fetchEffects('')
              }
            }}
            className="pl-9 pr-8"
          />
          {searchTerm && (
            <button
              type="button"
              onClick={() => {
                setSearchTerm('')
                fetchEffects('')
              }}
              className="absolute right-3 top-1/2 -translate-y-1/2 text-muted-foreground hover:text-foreground"
            >
              <X className="h-3.5 w-3.5" />
            </button>
          )}
        </div>
        <Button onClick={() => fetchEffects(searchTerm)} size="sm" disabled={loading}>
          {loading ? <Loader2 className="w-4 h-4 animate-spin" /> : <Search className="w-4 h-4" />}
        </Button>
        {(['all', 'fx', 'dance'] as Filter[]).map((f) => (
          <Button
            key={f}
            size="sm"
            variant={filter === f ? 'default' : 'outline'}
            onClick={() => setFilter(f)}
          >
            {f.toUpperCase()}
          </Button>
        ))}
      </div>

      {/* Bulk actions */}
      {importable.length > 0 && (
        <div className="flex items-center gap-2 flex-wrap">
          <Button
            variant="outline"
            size="sm"
            className="text-xs h-8"
            disabled={!!batchProgress}
            onClick={() =>
              setSelected((prev) =>
                prev.size === importable.length ? new Set() : new Set(importable.map((e) => e.lib)),
              )
            }
          >
            {selected.size === importable.length
              ? 'Deselect All'
              : `Select All (${importable.length})`}
          </Button>
          {selected.size > 0 && (
            <Button size="sm" className="h-8" onClick={importSelected} disabled={!!batchProgress}>
              {batchProgress ? (
                <Loader2 className="w-4 h-4 animate-spin mr-1" />
              ) : (
                <Download className="w-4 h-4 mr-1" />
              )}
              Import {selected.size} selected
            </Button>
          )}
          {batchProgress && (
            <span className="text-xs text-muted-foreground">
              {batchProgress.done}/{batchProgress.total}
            </span>
          )}
        </div>
      )}

      {/* Error */}
      {error && (
        <div className="rounded-lg border px-4 py-3 text-sm bg-destructive/10 border-destructive/20 text-destructive flex items-center gap-2">
          <AlertCircle className="w-4 h-4 shrink-0" />
          {error}
        </div>
      )}

      {/* Empty */}
      {!loading && visible.length === 0 && !error && (
        <div className="text-center py-12 text-muted-foreground">
          <Sparkles className="w-12 h-12 mx-auto mb-3 opacity-50" />
          <p className="text-sm">No effects found</p>
        </div>
      )}

      {/* Grid */}
      {visible.length > 0 && (
        <div
          className={cn(
            'grid grid-cols-2 md:grid-cols-4 lg:grid-cols-6 gap-3',
            loading && 'opacity-50',
          )}
        >
          {visible.map((e) => {
            const imported = e.present && e.nitroExists
            const isSelected = selected.has(e.lib)
            return (
              <div
                key={e.lib}
                className={cn(
                  'rounded-lg border overflow-hidden bg-card relative hover:border-border transition-all',
                  imported && 'ring-1 ring-[var(--admin-success)]/30',
                  isSelected && 'ring-2 ring-primary border-primary',
                )}
              >
                {!imported && (
                  <button
                    type="button"
                    onClick={() => toggle(e.lib)}
                    className={cn(
                      'absolute top-1.5 left-1.5 z-10 w-5 h-5 rounded border-2 flex items-center justify-center transition-colors',
                      isSelected
                        ? 'bg-primary border-primary text-primary-foreground'
                        : 'bg-background/80 border-muted-foreground/30 hover:border-muted-foreground',
                    )}
                  >
                    {isSelected && <Check className="w-3 h-3" />}
                  </button>
                )}
                <div
                  className={cn(
                    'flex flex-col items-center justify-center h-20 gap-1',
                    e.type === 'dance'
                      ? 'bg-gradient-to-br from-[var(--admin-warning)]/25 to-[var(--admin-warning)]/10'
                      : 'bg-gradient-to-br from-[var(--admin-accent)]/25 to-[var(--admin-accent)]/10',
                  )}
                >
                  {e.type === 'dance' ? (
                    <Music className="w-7 h-7 text-[var(--admin-warning)]/80" />
                  ) : (
                    <Sparkles className="w-7 h-7 text-[var(--admin-accent-text)]" />
                  )}
                  <span className="text-[10px] font-semibold uppercase tracking-wide text-muted-foreground">
                    {e.type}
                  </span>
                </div>
                <div className="px-2.5 py-2 border-t space-y-1">
                  <div className="text-xs font-bold truncate">{e.lib}</div>
                  <div className="text-[10px] text-muted-foreground truncate">id {e.id}</div>
                  <div className="pt-1">
                    {imported ? (
                      <div className="flex items-center gap-1">
                        <Badge className="text-[10px] px-1.5 py-0 bg-[var(--admin-success-subtle)] text-[var(--admin-success)] border-0 gap-0.5 flex-1 justify-center">
                          <Check className="w-2.5 h-2.5" />
                          Imported
                        </Badge>
                        <Button
                          variant="ghost"
                          size="sm"
                          className="h-5 w-5 p-0 shrink-0"
                          title="Remove effect"
                          disabled={busyLib === e.lib || !!batchProgress}
                          onClick={() => remove(e)}
                        >
                          <Trash2 className="w-3 h-3" />
                        </Button>
                      </div>
                    ) : (
                      <Button
                        size="sm"
                        variant="outline"
                        className="w-full text-xs h-7"
                        disabled={busyLib === e.lib || !!batchProgress}
                        onClick={() => importOne(e)}
                      >
                        {busyLib === e.lib ? (
                          <Loader2 className="w-3 h-3 animate-spin mr-1" />
                        ) : (
                          <Download className="w-3 h-3 mr-1" />
                        )}
                        Import
                      </Button>
                    )}
                  </div>
                </div>
              </div>
            )
          })}
        </div>
      )}
    </div>
  )
}