'use client'

/**
 * ErrorTrendChart - #43 錯誤趨勢圖表
 * ===================================
 * Phase 10: Sentry + OpenClaw + UI 整合
 *
 * Nothing.tech 視覺規範:
 * - 純白底色 (bg-white)
 * - 極細淺灰邊框 (border border-gray-200)
 * - 無圓角或微圓角 (rounded-sm)
 * - 嚴禁陰影 (shadow-none)
 *
 * 建立: 2026-03-26 (台北時區)
 * 建立者: Claude Code (#43 Error UI)
 */

import { useMemo } from 'react'
import { useTranslations } from 'next-intl'
import { cn } from '@/lib/utils'
import { TrendingUp, TrendingDown, Minus, Activity } from 'lucide-react'
import type { ErrorTrendResponse, ErrorTrendPoint } from '@/lib/api-client'

// =============================================================================
// Component Props
// =============================================================================

interface ErrorTrendChartProps {
  data: ErrorTrendResponse | null
  loading?: boolean
  error?: string | null
  onPeriodChange?: (period: '24h' | '7d' | '30d') => void
  activePeriod?: '24h' | '7d' | '30d'
  className?: string
}

// =============================================================================
// Sparkline Component
// =============================================================================

function Sparkline({
  data,
  width = 200,
  height = 60,
}: {
  data: ErrorTrendPoint[]
  width?: number
  height?: number
}) {
  const path = useMemo(() => {
    if (data.length === 0) return ''

    const maxCount = Math.max(...data.map((d) => d.count), 1)
    const minCount = Math.min(...data.map((d) => d.count), 0)
    const range = maxCount - minCount || 1

    const points = data.map((d, i) => {
      const x = (i / (data.length - 1)) * width
      const y = height - ((d.count - minCount) / range) * height
      return `${x},${y}`
    })

    return `M ${points.join(' L ')}`
  }, [data, width, height])

  const areaPath = useMemo(() => {
    if (data.length === 0) return ''

    const maxCount = Math.max(...data.map((d) => d.count), 1)
    const minCount = Math.min(...data.map((d) => d.count), 0)
    const range = maxCount - minCount || 1

    const points = data.map((d, i) => {
      const x = (i / (data.length - 1)) * width
      const y = height - ((d.count - minCount) / range) * height
      return `${x},${y}`
    })

    return `M 0,${height} L ${points.join(' L ')} L ${width},${height} Z`
  }, [data, width, height])

  if (data.length === 0) {
    return (
      <svg width={width} height={height} className="text-gray-300">
        <line x1="0" y1={height / 2} x2={width} y2={height / 2} stroke="currentColor" strokeDasharray="4" />
      </svg>
    )
  }

  return (
    <svg width={width} height={height} className="overflow-visible">
      {/* Area fill */}
      <path
        d={areaPath}
        fill="url(#gradient)"
        fillOpacity="0.3"
      />
      {/* Line */}
      <path
        d={path}
        fill="none"
        stroke="currentColor"
        strokeWidth="2"
        strokeLinecap="round"
        strokeLinejoin="round"
        className="text-red-500"
      />
      {/* Gradient definition */}
      <defs>
        <linearGradient id="gradient" x1="0" y1="0" x2="0" y2="1">
          <stop offset="0%" stopColor="rgb(239 68 68)" stopOpacity="0.4" />
          <stop offset="100%" stopColor="rgb(239 68 68)" stopOpacity="0" />
        </linearGradient>
      </defs>
    </svg>
  )
}

// =============================================================================
// Period Selector Component
// =============================================================================

function PeriodSelector({
  activePeriod,
  onChange,
}: {
  activePeriod: '24h' | '7d' | '30d'
  onChange?: (period: '24h' | '7d' | '30d') => void
}) {
  const periods: Array<{ value: '24h' | '7d' | '30d'; label: string }> = [
    { value: '24h', label: '24h' },
    { value: '7d', label: '7d' },
    { value: '30d', label: '30d' },
  ]

  return (
    <div className="flex items-center gap-1 bg-gray-100 rounded p-0.5">
      {periods.map(({ value, label }) => (
        <button
          key={value}
          onClick={() => onChange?.(value)}
          className={cn(
            'px-2 py-0.5 text-xs rounded transition-colors',
            activePeriod === value
              ? 'bg-white text-gray-900 shadow-sm'
              : 'text-gray-500 hover:text-gray-700',
          )}
        >
          {label}
        </button>
      ))}
    </div>
  )
}

// =============================================================================
// Main Component
// =============================================================================

export function ErrorTrendChart({
  data,
  loading = false,
  error = null,
  onPeriodChange,
  activePeriod = '24h',
  className,
}: ErrorTrendChartProps) {
  const t = useTranslations('errors')

  // Loading state
  if (loading) {
    return (
      <div className={cn(
        'bg-white border border-gray-200 rounded-sm p-4',
        className
      )}>
        <div className="animate-pulse space-y-3">
          <div className="flex items-center justify-between">
            <div className="h-4 bg-gray-200 rounded w-1/4" />
            <div className="h-5 bg-gray-200 rounded w-16" />
          </div>
          <div className="h-16 bg-gray-100 rounded" />
          <div className="flex items-center justify-between">
            <div className="h-6 bg-gray-200 rounded w-16" />
            <div className="h-4 bg-gray-200 rounded w-24" />
          </div>
        </div>
      </div>
    )
  }

  // Error state
  if (error) {
    return (
      <div className={cn(
        'bg-white border border-red-200 rounded-sm p-4',
        className
      )}>
        <div className="flex items-center gap-2 text-red-600">
          <Activity className="h-4 w-4" />
          <span className="text-sm">{error}</span>
        </div>
      </div>
    )
  }

  // Empty state
  if (!data) {
    return (
      <div className={cn(
        'bg-white border border-gray-200 rounded-sm p-4',
        className
      )}>
        <div className="text-center text-gray-500 py-4">
          <Activity className="h-8 w-8 mx-auto mb-2 opacity-50" />
          <p className="text-sm">{t('noTrendData')}</p>
        </div>
      </div>
    )
  }

  // Trend indicator
  const TrendIcon = data.change_percent > 0 ? TrendingUp : data.change_percent < 0 ? TrendingDown : Minus
  const trendColor = data.change_percent > 0 ? 'text-red-500' : data.change_percent < 0 ? 'text-green-500' : 'text-gray-400'
  const trendBg = data.change_percent > 0 ? 'bg-red-50' : data.change_percent < 0 ? 'bg-green-50' : 'bg-gray-50'

  return (
    <div className={cn(
      'bg-white border border-gray-200 rounded-sm p-4',
      className
    )}>
      {/* Header */}
      <div className="flex items-center justify-between mb-3">
        <div className="flex items-center gap-2">
          <Activity className="h-4 w-4 text-gray-600" />
          <h3 className="text-sm font-medium text-gray-900">{t('errorTrend')}</h3>
        </div>
        <PeriodSelector
          activePeriod={activePeriod}
          onChange={onPeriodChange}
        />
      </div>

      {/* Chart */}
      <div className="py-2">
        <Sparkline data={data.data} width={280} height={60} />
      </div>

      {/* Footer */}
      <div className="flex items-center justify-between mt-2 pt-2 border-t border-gray-100">
        {/* Total Count */}
        <div>
          <div className="text-xl font-semibold text-gray-900">
            {data.total_count.toLocaleString()}
          </div>
          <div className="text-xs text-gray-500">
            {t('totalErrors', { period: data.period })}
          </div>
        </div>

        {/* Change Percent */}
        <div className={cn(
          'flex items-center gap-1 px-2 py-1 rounded',
          trendBg,
          trendColor,
        )}>
          <TrendIcon className="h-4 w-4" />
          <span className="text-sm font-medium">
            {data.change_percent > 0 ? '+' : ''}{data.change_percent.toFixed(1)}%
          </span>
        </div>
      </div>
    </div>
  )
}