'use client'

import { useState, useEffect, useMemo, useCallback } from 'react'
import { RefreshCw } from 'lucide-react'
import { TIME_RANGE_CONFIGS, buildChartData } from './types'
import type { TimeRange, ChartPoint, TimeRangeConfig } from './types'
import { StockChartCore } from './stock-chart-core'
import { cn } from '@/lib/utils'

export interface StockChartProps {
  symbol?: string
  range?: TimeRange
  endDateTime?: string // ISO 8601 UTC if provided
  className?: string
}

function getNowUtcIso() {
  return new Date().toISOString().replace(/\.\d{3}Z$/, 'Z')
}

function resolveDurationForRequest(cfg: TimeRangeConfig) {
  if (cfg.label === '1D') return '4 D'
  if (cfg.label === '5D') return '8 D'

  if (cfg.label !== 'YTD') return cfg.duration

  const now = new Date()
  const jan1Utc = new Date(Date.UTC(now.getUTCFullYear(), 0, 1, 0, 0, 0))
  const daysSince = Math.max(
    1,
    Math.ceil((now.getTime() - jan1Utc.getTime()) / 86400000)
  )

  return `${daysSince} D`
}

function buildHistoricalLineUrl(
  symbol: string,
  cfg: TimeRangeConfig,
  endDateTime?: string
) {
  const resolvedEndDateTime = endDateTime?.trim() || getNowUtcIso()

  const params = new URLSearchParams({
    symbol: (symbol ?? '').trim().toUpperCase(),
    endDateTime: resolvedEndDateTime,
    duration: resolveDurationForRequest(cfg),
    barSize: cfg.barSize,
    whatToShow: 'Trades',
    useRth: 'true',
  })

  return `https://api.dongfeng-systems.org/api/market/historical-line?${params.toString()}`
}

export function StockChart({
  symbol,
  range = '1M',
  endDateTime,
  className,
}: StockChartProps) {
  const [data, setData] = useState<ChartPoint[]>([])
  const [loading, setLoading] = useState(false)
  const [error, setError] = useState<string | null>(null)

  const safeSymbol = (symbol ?? '').trim().toUpperCase()

  const rangeConfig: TimeRangeConfig | undefined = useMemo(
    () => TIME_RANGE_CONFIGS.find((r) => r.label === range),
    [range]
  )

  const validPrices = data
    .map((d) => d.price)
    .filter((price): price is number => price !== null)

  const minPrice = validPrices.length ? Math.min(...validPrices) : 0
  const maxPrice = validPrices.length ? Math.max(...validPrices) : 0

  const fetchData = useCallback(async () => {
    if (!safeSymbol) {
      setError('Missing symbol')
      setData([])
      return
    }

    if (!rangeConfig) {
      setError(`Invalid range: ${range}`)
      setData([])
      return
    }

    setLoading(true)
    setError(null)

    try {
      const url = buildHistoricalLineUrl(safeSymbol, rangeConfig, endDateTime)

      const res = await fetch(url, {
        method: 'GET',
        cache: 'no-store',
      })

      if (!res.ok) {
        const text = await res.text()
        throw new Error(`HTTP ${res.status}: ${text}`)
      }

      const json = await res.json()

      if (!Array.isArray(json)) {
        throw new Error('Unexpected response format')
      }

      const chartData = buildChartData(json, range)
      setData(chartData)
    } catch (e) {
      setError(e instanceof Error ? e.message : 'Failed to load data')
      setData([])
    } finally {
      setLoading(false)
    }
  }, [safeSymbol, rangeConfig, endDateTime, range])

  useEffect(() => {
    fetchData()
  }, [fetchData])

  return (
    <div className={cn('bg-card border border-border rounded-xl overflow-hidden', className)}>
      <div className="px-2 py-4 min-h-[300px] flex items-center justify-center">
        {loading && (
          <div className="flex flex-col items-center gap-3 text-muted-foreground">
            <RefreshCw className="w-5 h-5 animate-spin" />
            <p className="text-sm">Loading {safeSymbol || 'chart'}...</p>
          </div>
        )}

        {error && !loading && (
          <div className="flex flex-col items-center gap-2 text-center px-4">
            <p className="text-[oklch(0.55_0.22_25)] text-sm font-medium">Failed to load data</p>
            <p className="text-muted-foreground text-xs break-all">{error}</p>
            <button
              onClick={fetchData}
              className="mt-2 text-xs text-foreground border border-border rounded-md px-3 py-1.5 hover:bg-secondary transition-colors"
            >
              Retry
            </button>
          </div>
        )}

        {!loading && !error && data.length > 0 && rangeConfig && (
          <div className="w-full">
            <StockChartCore data={data} config={rangeConfig} />
          </div>
        )}

        {!loading && !error && data.length === 0 && (
          <p className="text-muted-foreground text-sm">No data available for this range.</p>
        )}
      </div>

      {!loading && !error && data.length > 0 && rangeConfig && (
        <div className="px-6 pb-4 flex items-center justify-between text-xs text-muted-foreground font-mono border-t border-border pt-3">
          <span>{data.length} bars · {rangeConfig.barSize}</span>
          <span>
            Range: ${minPrice.toFixed(2)} - ${maxPrice.toFixed(2)}
          </span>
        </div>
      )}
    </div>
  )
}