import { supabase } from './supabase.js'
import { getAllDecisions, setAllDecisions, clearAllDecisions } from './dataCache.js'
import { writeRawDecisions, clearAllStores, readAllRawDecisions } from './idb.js'
import { filterRowsToNyseTradingDays, countNonTradingDaysBetweenForAsset, countTradingDaysBetweenForAsset } from './marketCalendar.js'
import { computeBuyHoldEquity, computeStrategyEquity, calculateMetricsFromSeries, computeWinRate } from './perf.js'
import { STRATEGIES } from './strategies.js'

/**
 * 全局数据服务
 * 负责从 Supabase 加载数据、缓存管理和数据计算
 */
class DataService {
  constructor() {
    this.loading = false
    this.loaded = false
    this.agents = []
    this.tableRows = []
    this.lastUpdated = null
    this.dateBounds = { min: null, max: null }
    this.listeners = new Set()
    
    // Filter options cache
    this.useDbFilterCache = this._getDefaultUseDbFilterCache()
    this.nameOptions = []
    this.assetOptions = []
    this.modelOptions = []
    this.strategyOptions = []
  }

  _getDefaultUseDbFilterCache() {
    try {
      if (localStorage.getItem('disableDbFilterCache') === '1') return false
    } catch (_) {}
    const envFlag = ((import.meta.env.VITE_USE_DB_FILTER_CACHE || '') + '').toLowerCase()
    return envFlag === '1' || envFlag === 'true' || envFlag === 'yes' || envFlag === 'on'
  }

  /**
   * 订阅数据变化
   */
  subscribe(callback) {
    this.listeners.add(callback)
    return () => this.listeners.delete(callback)
  }

  /**
   * 通知所有订阅者
   */
  _notify() {
    this.listeners.forEach(callback => {
      try {
        callback({
          loading: this.loading,
          loaded: this.loaded,
          agents: this.agents,
          tableRows: this.tableRows,
          lastUpdated: this.lastUpdated,
          dateBounds: this.dateBounds,
          nameOptions: this.nameOptions,
          assetOptions: this.assetOptions,
          modelOptions: this.modelOptions,
          strategyOptions: this.strategyOptions
        })
      } catch (e) {
        console.error('[DataService] Error notifying listener:', e)
      }
    })
  }

  /**
   * 从数据库加载筛选选项
   */
  async loadFilterOptionsFromDb() {
    if (!this.useDbFilterCache) return null

    try {
      const { data, error } = await supabase
        .from('filter_options')
        .select('names, assets, models, strategies, updated_at')
        .eq('id', 'latest')
        .maybeSingle()

      if (error || !data) {
        const msg = (error && error.message) ? String(error.message).toLowerCase() : ''
        const code = (error && error.code) ? String(error.code) : ''
        const isNotFound = msg.includes('not found') || msg.includes('does not exist') || code === '42P01' || code === 'PGRST116'
        
        if (isNotFound) {
          this.useDbFilterCache = false
          try { localStorage.setItem('disableDbFilterCache', '1') } catch (_) {}
        }
        return null
      }

      return {
        names: data.names || [],
        assets: data.assets || [],
        models: data.models || [],
        strategies: data.strategies || []
      }
    } catch (e) {
      const msg = e && e.message ? String(e.message).toLowerCase() : ''
      if (msg.includes('not found') || msg.includes('does not exist')) {
        this.useDbFilterCache = false
        try { localStorage.setItem('disableDbFilterCache', '1') } catch (_) {}
      }
      return null
    }
  }

  /**
   * 保存筛选选项到数据库
   */
  async saveFilterOptionsToDb(names, assets, models, strategies) {
    if (!this.useDbFilterCache) return

    try {
      await supabase
        .from('filter_options')
        .upsert({ 
          id: 'latest', 
          names, 
          assets, 
          models, 
          strategies, 
          updated_at: new Date().toISOString() 
        }, { onConflict: 'id' })
    } catch (e) {
      const msg = e && e.message ? String(e.message).toLowerCase() : ''
      if (msg.includes('not found') || msg.includes('does not exist')) {
        this.useDbFilterCache = false
        try { localStorage.setItem('disableDbFilterCache', '1') } catch (_) {}
      }
    }
  }

  /**
   * 从 Supabase 拉取所有数据
   */
  async _fetchAllFromRemote() {
    const pageSize = 1000
    let from = 0
    const all = []

    while (true) {
      const to = from + pageSize - 1
      const { data, error } = await supabase
        .from('trading_decisions')
        .select('id, agent_name, asset, model, date, price, recommended_action, news_count, sentiment, created_at, updated_at')
        .order('updated_at', { ascending: false })
        .range(from, to)

      if (error) {
        console.error('[DataService] Error fetching data:', error)
        break
      }

      all.push(...(data || []))
      
      if (!data || data.length < pageSize) break
      from += pageSize
    }

    return all
  }

  /**
   * 计算单个分组的指标
   */
  async _computeAgentMetrics(row, allDecisions) {
    try {
      // 构建完整时间序列
      const seq = allDecisions
        .filter(r => r.agent_name === row.agent_name && r.asset === row.asset && r.model === row.model)
        .sort((a, b) => (a.date > b.date ? 1 : -1))

      const isCrypto = row.asset === 'BTC' || row.asset === 'ETH'
      const seqFiltered = isCrypto ? seq : (await filterRowsToNyseTradingDays(seq))

      // 计算日期范围
      const dates = seqFiltered.map(s => s.date).filter(Boolean).sort()
      const start_date = dates[0] || '-'
      const end_date = dates[dates.length - 1] || '-'

      let closed_days = 0
      if (dates.length > 1) {
        closed_days = await countNonTradingDaysBetweenForAsset(row.asset, start_date, end_date)
      }
      const trading_days = await countTradingDaysBetweenForAsset(row.asset, start_date, end_date)

      // 为每个策略计算指标
      const results = []
      for (const s of STRATEGIES) {
        const st = computeStrategyEquity(seqFiltered, 100000, s.fee, s.strategy, s.tradingMode)
        const stNoFee = computeStrategyEquity(seqFiltered, 100000, 0, s.strategy, s.tradingMode)
        const metrics = calculateMetricsFromSeries(st, isCrypto ? 'crypto' : 'stock')
        const metricsNoFee = calculateMetricsFromSeries(stNoFee, isCrypto ? 'crypto' : 'stock')
        const { winRate, trades } = computeWinRate(seqFiltered, s.strategy, s.tradingMode)
        const bhSeries = computeBuyHoldEquity(seqFiltered, 100000)
        const buy_hold_return = bhSeries.length ? (bhSeries[bhSeries.length - 1] - bhSeries[0]) / bhSeries[0] : 0

        results.push({
          decision_ids: seqFiltered.map(r => r.id).filter(Boolean),
          agent_name: row.agent_name,
          asset: row.asset,
          model: row.model,
          strategy: s.id,
          strategy_label: s.label,
          balance: st.length ? st[st.length - 1] : 100000,
          return_with_fees: metrics.total_return / 100,
          return_no_fees: metricsNoFee.total_return / 100,
          buy_hold_return,
          sharpe_ratio: metrics.sharpe_ratio,
          win_rate: winRate,
          trades,
          start_date,
          end_date,
          closed_days,
          trading_days,
          fee: s.fee,
          tradingMode: s.tradingMode,
          series: seqFiltered.map(r => ({ 
            id: r.id, 
            date: r.date, 
            price: r.price, 
            recommended_action: r.recommended_action 
          })),
          key: `${row.agent_name}|${row.asset}|${row.model}|${s.id}`
        })
      }

      return results
    } catch (e) {
      console.error('[DataService] Error computing metrics:', e)
      return []
    }
  }

  /**
   * 加载数据（主方法）
   */
  async load(forceRefresh = false) {
    if (this.loading) {
      console.log('[DataService] Already loading, skipping...')
      return
    }

    this.loading = true
    this._notify()

    try {
      // 1. 尝试从数据库加载筛选选项
      await this.loadFilterOptionsFromDb()

      // 2. 获取所有决策数据
      let all = null

      if (forceRefresh) {
        // 强制刷新：清除所有缓存，从远程拉取
        await clearAllStores()
        clearAllDecisions()
        all = await this._fetchAllFromRemote()
        setAllDecisions(all)
        await writeRawDecisions(all)
      } else {
        // 正常加载：先尝试内存缓存
        all = getAllDecisions()

        if (!all) {
          // 再尝试 IndexedDB 缓存
          const cached = await readAllRawDecisions()
          if (cached && cached.length) {
            all = cached
            setAllDecisions(all)
          }
        }

        if (!all) {
          // 最后从远程拉取
          all = await this._fetchAllFromRemote()
          setAllDecisions(all)
          await writeRawDecisions(all)
        }
      }

      // 3. 计算全局日期范围
      const allDates = all.map(r => r && r.date).filter(Boolean).sort()
      this.dateBounds = {
        min: allDates.length ? new Date(allDates[0]) : null,
        max: allDates.length ? new Date(allDates[allDates.length - 1]) : null
      }

      // 4. 按 agent_name|asset|model 分组去重
      const keyToRow = new Map()
      for (const row of all) {
        const key = `${row.agent_name}|${row.asset}|${row.model}`
        if (!keyToRow.has(key)) {
          keyToRow.set(key, row)
        }
      }

      // 5. 计算每个分组的指标
      const agents = []
      for (const row of keyToRow.values()) {
        const metrics = await this._computeAgentMetrics(row, all)
        agents.push(...metrics)
      }

      this.agents = agents

      // 6. 转换为表格行
      this.tableRows = agents.map(a => ({
        agent_name: a.agent_name,
        asset: a.asset,
        model: a.model,
        strategy: a.strategy,
        strategy_label: a.strategy_label,
        balance: a.balance,
        ret_with_fees: a.return_with_fees,
        ret_no_fees: a.return_no_fees,
        buy_hold: a.buy_hold_return,
        vs_bh_with_fees: a.return_with_fees - a.buy_hold_return,
        sharpe: a.sharpe_ratio,
        trading_days: a.trading_days,
        win_rate: a.win_rate,
        trades: a.trades,
        start_date: a.start_date,
        end_date: a.end_date,
        closed_date: a.closed_days,
        decision_ids: a.decision_ids,
        fee: a.fee,
        tradingMode: a.tradingMode,
        series: a.series,
        key: a.key
      }))

      // 7. 生成筛选选项
      this.nameOptions = Array.from(new Set(agents.map(a => a.agent_name)))
        .map(v => ({ label: v, value: v }))
      this.assetOptions = Array.from(new Set(agents.map(a => a.asset)))
        .map(v => ({ label: v, value: v }))
      this.modelOptions = Array.from(new Set(agents.map(a => a.model)))
        .map(v => ({ label: v, value: v }))
      this.strategyOptions = STRATEGIES.map(s => ({ label: s.label, value: s.id }))

      // 8. 保存筛选选项到数据库
      await this.saveFilterOptionsToDb(
        this.nameOptions.map(o => o.value),
        this.assetOptions.map(o => o.value),
        this.modelOptions.map(o => o.value),
        this.strategyOptions.map(o => o.value)
      )

      this.lastUpdated = Date.now()
      this.loaded = true

      console.log('[DataService] Data loaded successfully:', {
        agents: this.agents.length,
        tableRows: this.tableRows.length,
        names: this.nameOptions.length,
        assets: this.assetOptions.length
      })
    } catch (e) {
      console.error('[DataService] Error loading data:', e)
    } finally {
      this.loading = false
      this._notify()
    }
  }

  /**
   * 强制刷新数据
   */
  async forceRefresh() {
    return this.load(true)
  }

  /**
   * 获取当前状态
   */
  getState() {
    return {
      loading: this.loading,
      loaded: this.loaded,
      agents: this.agents,
      tableRows: this.tableRows,
      lastUpdated: this.lastUpdated,
      dateBounds: this.dateBounds,
      nameOptions: this.nameOptions,
      assetOptions: this.assetOptions,
      modelOptions: this.modelOptions,
      strategyOptions: this.strategyOptions
    }
  }
}

// 导出单例
export const dataService = new DataService()