package controller

import (
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"net/http"
	"strconv"
	"strings"
	"time"

	"github.com/QuantumNous/new-api/common"
	"github.com/QuantumNous/new-api/constant"
	"github.com/QuantumNous/new-api/model"
	"github.com/QuantumNous/new-api/service"
	"github.com/QuantumNous/new-api/setting/operation_setting"
	"github.com/QuantumNous/new-api/types"

	"github.com/shopspring/decimal"

	"github.com/gin-gonic/gin"
)

// https://github.com/songquanpeng/one-api/issues/79

type OpenAISubscriptionResponse struct {
	Object             string  `json:"object"`
	HasPaymentMethod   bool    `json:"has_payment_method"`
	SoftLimitUSD       float64 `json:"soft_limit_usd"`
	HardLimitUSD       float64 `json:"hard_limit_usd"`
	SystemHardLimitUSD float64 `json:"system_hard_limit_usd"`
	AccessUntil        int64   `json:"access_until"`
}

type OpenAIUsageDailyCost struct {
	Timestamp float64 `json:"timestamp"`
	LineItems []struct {
		Name string  `json:"name"`
		Cost float64 `json:"cost"`
	}
}

type OpenAICreditGrants struct {
	Object         string  `json:"object"`
	TotalGranted   float64 `json:"total_granted"`
	TotalUsed      float64 `json:"total_used"`
	TotalAvailable float64 `json:"total_available"`
}

type OpenAIUsageResponse struct {
	Object string `json:"object"`
	//DailyCosts []OpenAIUsageDailyCost `json:"daily_costs"`
	TotalUsage float64 `json:"total_usage"` // unit: 0.01 dollar
}

type OpenAISBUsageResponse struct {
	Msg  string `json:"msg"`
	Data *struct {
		Credit string `json:"credit"`
	} `json:"data"`
}

type AIProxyUserOverviewResponse struct {
	Success   bool   `json:"success"`
	Message   string `json:"message"`
	ErrorCode int    `json:"error_code"`
	Data      struct {
		TotalPoints float64 `json:"totalPoints"`
	} `json:"data"`
}

type API2GPTUsageResponse struct {
	Object         string  `json:"object"`
	TotalGranted   float64 `json:"total_granted"`
	TotalUsed      float64 `json:"total_used"`
	TotalRemaining float64 `json:"total_remaining"`
}

type APGC2DGPTUsageResponse struct {
	//Grants         interface{} `json:"grants"`
	Object         string  `json:"object"`
	TotalAvailable float64 `json:"total_available"`
	TotalGranted   float64 `json:"total_granted"`
	TotalUsed      float64 `json:"total_used"`
}

type SiliconFlowUsageResponse struct {
	Code    int    `json:"code"`
	Message string `json:"message"`
	Status  bool   `json:"status"`
	Data    struct {
		ID            string `json:"id"`
		Name          string `json:"name"`
		Image         string `json:"image"`
		Email         string `json:"email"`
		IsAdmin       bool   `json:"isAdmin"`
		Balance       string `json:"balance"`
		Status        string `json:"status"`
		Introduction  string `json:"introduction"`
		Role          string `json:"role"`
		ChargeBalance string `json:"chargeBalance"`
		TotalBalance  string `json:"totalBalance"`
		Category      string `json:"category"`
	} `json:"data"`
}

type DeepSeekUsageResponse struct {
	IsAvailable  bool `json:"is_available"`
	BalanceInfos []struct {
		Currency        string `json:"currency"`
		TotalBalance    string `json:"total_balance"`
		GrantedBalance  string `json:"granted_balance"`
		ToppedUpBalance string `json:"topped_up_balance"`
	} `json:"balance_infos"`
}

type OpenRouterCreditResponse struct {
	Data struct {
		TotalCredits float64 `json:"total_credits"`
		TotalUsage   float64 `json:"total_usage"`
	} `json:"data"`
}

// GetAuthHeader get auth header
func GetAuthHeader(token string) http.Header {
	h := http.Header{}
	h.Add("Authorization", fmt.Sprintf("Bearer %s", token))
	return h
}

// GetClaudeAuthHeader get claude auth header
func GetClaudeAuthHeader(token string) http.Header {
	h := http.Header{}
	h.Add("x-api-key", token)
	h.Add("anthropic-version", "2023-06-01")
	return h
}

func GetResponseBody(method, url string, channel *model.Channel, headers http.Header) ([]byte, error) {
	return GetResponseBodyWithContext(context.Background(), method, url, channel, headers)
}

// GetResponseBodyWithContext 与 GetResponseBody 相同，但将请求绑定到 ctx（用于取消与超时）。
func GetResponseBodyWithContext(ctx context.Context, method, url string, channel *model.Channel, headers http.Header) ([]byte, error) {
	req, err := http.NewRequestWithContext(ctx, method, url, nil)
	if err != nil {
		return nil, err
	}
	for k := range headers {
		req.Header.Add(k, headers.Get(k))
	}
	client, err := service.NewProxyHttpClient(channel.GetSetting().Proxy)
	if err != nil {
		return nil, err
	}
	res, err := client.Do(req)
	if err != nil {
		return nil, err
	}
	if res.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("status code: %d", res.StatusCode)
	}
	body, err := io.ReadAll(res.Body)
	if err != nil {
		return nil, err
	}
	err = res.Body.Close()
	if err != nil {
		return nil, err
	}
	return body, nil
}

func updateChannelCloseAIBalance(channel *model.Channel) (float64, error) {
	url := fmt.Sprintf("%s/dashboard/billing/credit_grants", channel.GetBaseURL())
	body, err := GetResponseBody("GET", url, channel, GetAuthHeader(channel.Key))

	if err != nil {
		return 0, err
	}
	response := OpenAICreditGrants{}
	err = json.Unmarshal(body, &response)
	if err != nil {
		return 0, err
	}
	channel.UpdateBalance(response.TotalAvailable)
	return response.TotalAvailable, nil
}

func updateChannelOpenAISBBalance(channel *model.Channel) (float64, error) {
	url := fmt.Sprintf("https://api.openai-sb.com/sb-api/user/status?api_key=%s", channel.Key)
	body, err := GetResponseBody("GET", url, channel, GetAuthHeader(channel.Key))
	if err != nil {
		return 0, err
	}
	response := OpenAISBUsageResponse{}
	err = json.Unmarshal(body, &response)
	if err != nil {
		return 0, err
	}
	if response.Data == nil {
		return 0, errors.New(response.Msg)
	}
	balance, err := strconv.ParseFloat(response.Data.Credit, 64)
	if err != nil {
		return 0, err
	}
	channel.UpdateBalance(balance)
	return balance, nil
}

func updateChannelAIProxyBalance(channel *model.Channel) (float64, error) {
	url := "https://aiproxy.io/api/report/getUserOverview"
	headers := http.Header{}
	headers.Add("Api-Key", channel.Key)
	body, err := GetResponseBody("GET", url, channel, headers)
	if err != nil {
		return 0, err
	}
	response := AIProxyUserOverviewResponse{}
	err = json.Unmarshal(body, &response)
	if err != nil {
		return 0, err
	}
	if !response.Success {
		return 0, fmt.Errorf("code: %d, message: %s", response.ErrorCode, response.Message)
	}
	channel.UpdateBalance(response.Data.TotalPoints)
	return response.Data.TotalPoints, nil
}

func updateChannelAPI2GPTBalance(channel *model.Channel) (float64, error) {
	url := "https://api.api2gpt.com/dashboard/billing/credit_grants"
	body, err := GetResponseBody("GET", url, channel, GetAuthHeader(channel.Key))

	if err != nil {
		return 0, err
	}
	response := API2GPTUsageResponse{}
	err = json.Unmarshal(body, &response)
	if err != nil {
		return 0, err
	}
	channel.UpdateBalance(response.TotalRemaining)
	return response.TotalRemaining, nil
}

func updateChannelSiliconFlowBalance(channel *model.Channel) (float64, error) {
	url := "https://api.siliconflow.cn/v1/user/info"
	body, err := GetResponseBody("GET", url, channel, GetAuthHeader(channel.Key))
	if err != nil {
		return 0, err
	}
	response := SiliconFlowUsageResponse{}
	err = json.Unmarshal(body, &response)
	if err != nil {
		return 0, err
	}
	if response.Code != 20000 {
		return 0, fmt.Errorf("code: %d, message: %s", response.Code, response.Message)
	}
	balance, err := strconv.ParseFloat(response.Data.TotalBalance, 64)
	if err != nil {
		return 0, err
	}
	channel.UpdateBalance(balance)
	return balance, nil
}

func updateChannelDeepSeekBalance(channel *model.Channel) (float64, error) {
	url := "https://api.deepseek.com/user/balance"
	body, err := GetResponseBody("GET", url, channel, GetAuthHeader(channel.Key))
	if err != nil {
		return 0, err
	}
	response := DeepSeekUsageResponse{}
	err = json.Unmarshal(body, &response)
	if err != nil {
		return 0, err
	}
	index := -1
	for i, balanceInfo := range response.BalanceInfos {
		if balanceInfo.Currency == "CNY" {
			index = i
			break
		}
	}
	if index == -1 {
		return 0, errors.New("currency CNY not found")
	}
	balance, err := strconv.ParseFloat(response.BalanceInfos[index].TotalBalance, 64)
	if err != nil {
		return 0, err
	}
	channel.UpdateBalance(balance)
	return balance, nil
}

func updateChannelAIGC2DBalance(channel *model.Channel) (float64, error) {
	url := "https://api.aigc2d.com/dashboard/billing/credit_grants"
	body, err := GetResponseBody("GET", url, channel, GetAuthHeader(channel.Key))
	if err != nil {
		return 0, err
	}
	response := APGC2DGPTUsageResponse{}
	err = json.Unmarshal(body, &response)
	if err != nil {
		return 0, err
	}
	channel.UpdateBalance(response.TotalAvailable)
	return response.TotalAvailable, nil
}

func updateChannelOpenRouterBalance(channel *model.Channel) (float64, error) {
	url := "https://openrouter.ai/api/v1/credits"
	body, err := GetResponseBody("GET", url, channel, GetAuthHeader(channel.Key))
	if err != nil {
		return 0, err
	}
	response := OpenRouterCreditResponse{}
	err = json.Unmarshal(body, &response)
	if err != nil {
		return 0, err
	}
	balance := response.Data.TotalCredits - response.Data.TotalUsage
	channel.UpdateBalance(balance)
	return balance, nil
}

func updateChannelMoonshotBalance(channel *model.Channel) (float64, error) {
	url := "https://api.moonshot.cn/v1/users/me/balance"
	body, err := GetResponseBody("GET", url, channel, GetAuthHeader(channel.Key))
	if err != nil {
		return 0, err
	}

	type MoonshotBalanceData struct {
		AvailableBalance float64 `json:"available_balance"`
		VoucherBalance   float64 `json:"voucher_balance"`
		CashBalance      float64 `json:"cash_balance"`
	}

	type MoonshotBalanceResponse struct {
		Code   int                 `json:"code"`
		Data   MoonshotBalanceData `json:"data"`
		Scode  string              `json:"scode"`
		Status bool                `json:"status"`
	}

	response := MoonshotBalanceResponse{}
	err = json.Unmarshal(body, &response)
	if err != nil {
		return 0, err
	}
	if !response.Status || response.Code != 0 {
		return 0, fmt.Errorf("failed to update moonshot balance, status: %v, code: %d, scode: %s", response.Status, response.Code, response.Scode)
	}
	availableBalanceCny := response.Data.AvailableBalance
	availableBalanceUsd := decimal.NewFromFloat(availableBalanceCny).Div(decimal.NewFromFloat(operation_setting.Price)).InexactFloat64()
	channel.UpdateBalance(availableBalanceUsd)
	return availableBalanceUsd, nil
}

type upstreamChannelBalanceResponse struct {
	Success bool    `json:"success"`
	Message string  `json:"message"`
	Balance float64 `json:"balance"`
}

const (
	channelBalanceAlertLevelNone = "none"
	channelBalanceAlertLevelSoft = "soft"
	channelBalanceAlertLevelRisk = "risk"
)

func getChannelBalanceAlertConfig() (enabled bool, softThreshold float64, riskThreshold float64) {
	softThreshold = 50
	riskThreshold = 20

	common.OptionMapRWMutex.RLock()
	enabled = common.OptionMap["ChannelBalanceAlertEnabled"] == "true"
	if raw, ok := common.OptionMap["ChannelBalanceSoftAlertThreshold"]; ok {
		if val, err := strconv.ParseFloat(strings.TrimSpace(raw), 64); err == nil && val >= 0 {
			softThreshold = val
		}
	}
	if raw, ok := common.OptionMap["ChannelBalanceRiskAlertThreshold"]; ok {
		if val, err := strconv.ParseFloat(strings.TrimSpace(raw), 64); err == nil && val >= 0 {
			riskThreshold = val
		}
	}
	common.OptionMapRWMutex.RUnlock()

	if riskThreshold > softThreshold {
		riskThreshold = softThreshold
	}
	return enabled, softThreshold, riskThreshold
}

// getChannelBalanceAlertLevel 按「剩余额度」比较阈值；渠道 balance 字段即剩余（计费会同步扣减）。
func getChannelBalanceAlertLevel(remaining float64, softThreshold float64, riskThreshold float64) string {
	if remaining <= riskThreshold {
		return channelBalanceAlertLevelRisk
	}
	if remaining <= softThreshold {
		return channelBalanceAlertLevelSoft
	}
	return channelBalanceAlertLevelNone
}

func persistChannelBalanceAlertLevel(channel *model.Channel, level string) {
	if channel == nil || channel.Id <= 0 {
		return
	}
	otherInfo := channel.GetOtherInfo()
	otherInfo["balance_alert_level"] = level
	otherInfo["balance_alert_at"] = common.GetTimestamp()
	channel.SetOtherInfo(otherInfo)
	if err := model.DB.Model(&model.Channel{}).
		Where("id = ?", channel.Id).
		Update("other_info", channel.OtherInfo).Error; err != nil {
		common.SysLog(fmt.Sprintf("failed to persist balance alert level: channel_id=%d, err=%v", channel.Id, err))
	}
}

func notifyChannelBalanceAlertIfNeeded(channel *model.Channel, oldBalance float64, newBalance float64) {
	if channel == nil || channel.Id <= 0 {
		return
	}
	enabled, softThreshold, riskThreshold := getChannelBalanceAlertConfig()
	if !enabled {
		return
	}

	newLevel := getChannelBalanceAlertLevel(newBalance, softThreshold, riskThreshold)
	otherInfo := channel.GetOtherInfo()
	oldLevel := strings.TrimSpace(common.Interface2String(otherInfo["balance_alert_level"]))
	if oldLevel == "" {
		oldLevel = getChannelBalanceAlertLevel(oldBalance, softThreshold, riskThreshold)
	}
	persistChannelBalanceAlertLevel(channel, newLevel)

	if newLevel == channelBalanceAlertLevelNone || newLevel == oldLevel {
		return
	}

	levelText := "柔和提示"
	threshold := softThreshold
	if newLevel == channelBalanceAlertLevelRisk {
		levelText = "风险警告"
		threshold = riskThreshold
	}

	title := fmt.Sprintf("渠道余额%s（%s）", levelText, channel.Name)
	content := fmt.Sprintf(
		"渠道“%s”（ID:%d）剩余额度 %.2f，已低于阈值 %.2f，请及时处理。",
		channel.Name,
		channel.Id,
		newBalance,
		threshold,
	)
	err := service.PublishUserMessage(&model.UserMessage{
		ReceiverMinRole: common.RoleAdminUser,
		Type:            "channel_balance_alert",
		Title:           title,
		Content:         content,
		BizType:         "channel_balance_alert",
		BizID:           channel.Id,
	})
	if err != nil {
		common.SysLog(fmt.Sprintf("failed to publish channel balance alert message: channel_id=%d, err=%v", channel.Id, err))
	}
}

func tryUpdateTFOpenMirroredChannelBalance(channel *model.Channel) (float64, bool, error) {
	otherInfo := channel.GetOtherInfo()
	if strings.TrimSpace(common.Interface2String(otherInfo["source"])) != "tokenfactory_open" {
		return 0, false, nil
	}
	upstreamID := common.String2Int(common.Interface2String(otherInfo["upstream_channel_id"]))
	if upstreamID <= 0 {
		return 0, true, errors.New("同步渠道缺少 upstream_channel_id")
	}
	baseURL := strings.TrimRight(strings.TrimSpace(channel.GetBaseURL()), "/")
	if baseURL == "" {
		return 0, true, errors.New("同步渠道缺少上游平台地址")
	}
	url := fmt.Sprintf("%s/api/channel/update_balance/%d", baseURL, upstreamID)
	headers := GetAuthHeader(channel.Key)
	headers.Set("X-TokenFactory-Open-Sync-Secret", strings.TrimSpace(channel.Key))
	body, err := GetResponseBody("GET", url, channel, headers)
	if err != nil {
		return 0, true, err
	}
	resp := upstreamChannelBalanceResponse{}
	if err := json.Unmarshal(body, &resp); err != nil {
		return 0, true, err
	}
	if !resp.Success {
		msg := strings.TrimSpace(resp.Message)
		if msg == "" {
			msg = "上游余额接口返回失败"
		}
		return 0, true, errors.New(msg)
	}
	channel.UpdateBalance(resp.Balance)
	return resp.Balance, true, nil
}

func updateChannelBalance(channel *model.Channel) (float64, error) {
	if balance, handled, err := tryUpdateTFOpenMirroredChannelBalance(channel); handled {
		return balance, err
	}
	baseURL := constant.ChannelBaseURLs[channel.Type]
	if channel.GetBaseURL() == "" {
		channel.BaseURL = &baseURL
	}
	switch channel.Type {
	case constant.ChannelTypeOpenAI:
		if channel.GetBaseURL() != "" {
			baseURL = channel.GetBaseURL()
		}
	case constant.ChannelTypeAzure:
		return 0, errors.New("尚未实现")
	case constant.ChannelTypeCustom:
		baseURL = channel.GetBaseURL()
	//case common.ChannelTypeOpenAISB:
	//	return updateChannelOpenAISBBalance(channel)
	case constant.ChannelTypeAIProxy:
		return updateChannelAIProxyBalance(channel)
	case constant.ChannelTypeAPI2GPT:
		return updateChannelAPI2GPTBalance(channel)
	case constant.ChannelTypeAIGC2D:
		return updateChannelAIGC2DBalance(channel)
	case constant.ChannelTypeSiliconFlow:
		return updateChannelSiliconFlowBalance(channel)
	case constant.ChannelTypeDeepSeek:
		return updateChannelDeepSeekBalance(channel)
	case constant.ChannelTypeOpenRouter:
		return updateChannelOpenRouterBalance(channel)
	case constant.ChannelTypeMoonshot:
		return updateChannelMoonshotBalance(channel)
	default:
		return 0, errors.New("尚未实现")
	}
	url := fmt.Sprintf("%s/v1/dashboard/billing/subscription", baseURL)

	body, err := GetResponseBody("GET", url, channel, GetAuthHeader(channel.Key))
	if err != nil {
		return 0, err
	}
	subscription := OpenAISubscriptionResponse{}
	err = json.Unmarshal(body, &subscription)
	if err != nil {
		return 0, err
	}
	now := time.Now()
	startDate := fmt.Sprintf("%s-01", now.Format("2006-01"))
	endDate := now.Format("2006-01-02")
	if !subscription.HasPaymentMethod {
		startDate = now.AddDate(0, 0, -100).Format("2006-01-02")
	}
	url = fmt.Sprintf("%s/v1/dashboard/billing/usage?start_date=%s&end_date=%s", baseURL, startDate, endDate)
	body, err = GetResponseBody("GET", url, channel, GetAuthHeader(channel.Key))
	if err != nil {
		return 0, err
	}
	usage := OpenAIUsageResponse{}
	err = json.Unmarshal(body, &usage)
	if err != nil {
		return 0, err
	}
	balance := subscription.HardLimitUSD - usage.TotalUsage/100
	channel.UpdateBalance(balance)
	return balance, nil
}

func UpdateChannelBalance(c *gin.Context) {
	id, err := strconv.Atoi(c.Param("id"))
	if err != nil {
		common.ApiError(c, err)
		return
	}
	channel, err := model.CacheGetChannel(id)
	if err != nil {
		common.ApiError(c, err)
		return
	}
	if channel.ChannelInfo.IsMultiKey {
		c.JSON(http.StatusOK, gin.H{
			"success": false,
			"message": "多密钥渠道不支持余额查询",
		})
		return
	}
	oldBalance := channel.Balance
	balance, err := updateChannelBalance(channel)
	if err != nil {
		common.ApiError(c, err)
		return
	}
	notifyChannelBalanceAlertIfNeeded(channel, oldBalance, balance)
	c.JSON(http.StatusOK, gin.H{
		"success": true,
		"message": "",
		"balance": balance,
	})
}

func updateAllChannelsBalance() error {
	channels, err := model.GetAllChannels(0, 0, true, false)
	if err != nil {
		return err
	}
	for _, channel := range channels {
		if channel.Status != common.ChannelStatusEnabled {
			continue
		}
		if channel.ChannelInfo.IsMultiKey {
			continue // skip multi-key channels
		}
		// TODO: support Azure
		//if channel.Type != common.ChannelTypeOpenAI && channel.Type != common.ChannelTypeCustom {
		//	continue
		//}
		oldBalance := channel.Balance
		balance, err := updateChannelBalance(channel)
		if err != nil {
			continue
		} else {
			notifyChannelBalanceAlertIfNeeded(channel, oldBalance, balance)
			// err is nil & balance <= 0 means quota is used up
			if balance <= 0 {
				service.DisableChannel(*types.NewChannelError(channel.Id, channel.Type, channel.Name, channel.ChannelInfo.IsMultiKey, "", channel.GetAutoBan()), "余额不足")
			}
		}
		time.Sleep(common.RequestInterval)
	}
	return nil
}

func UpdateAllChannelsBalance(c *gin.Context) {
	// TODO: make it async
	err := updateAllChannelsBalance()
	if err != nil {
		common.ApiError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{
		"success": true,
		"message": "",
	})
	return
}

func AutomaticallyUpdateChannels(frequency int) {
	for {
		time.Sleep(time.Duration(frequency) * time.Minute)
		common.SysLog("updating all channels")
		_ = updateAllChannelsBalance()
		common.SysLog("channels update done")
	}
}