package api

import (
	"strconv"
	"time"

	"github.com/gin-gonic/gin"
	"github.com/openteam/server/internal/pkg/resp"
	"github.com/openteam/server/internal/store"
)

// UsageSummary GET /api/v1/usage/summary — 今日/本月汇总。
func (h *Handler) UsageSummary(c *gin.Context) {
	u, _ := userFromContext(c)
	now := time.Now().UTC()
	today := now.Format("2006-01-02")
	month := now.Format("2006-01")

	var todayReq, monthReq int64
	var todayTok, monthTok int64
	var todayCost, monthCost float64
	h.a.DB.Model(&store.UsageDaily{}).Where("user_id = ? AND date = ?", u.ID, today).
		Select("COALESCE(SUM(requests),0), COALESCE(SUM(input_tokens+output_tokens+cache_read_tokens),0), COALESCE(SUM(cost),0)").
		Row().Scan(&todayReq, &todayTok, &todayCost)
	h.a.DB.Model(&store.UsageDaily{}).Where("user_id = ? AND date LIKE ?", u.ID, month+"%").
		Select("COALESCE(SUM(requests),0), COALESCE(SUM(input_tokens+output_tokens+cache_read_tokens),0), COALESCE(SUM(cost),0)").
		Row().Scan(&monthReq, &monthTok, &monthCost)
	resp.OK(c, gin.H{
		"today": gin.H{"requests": todayReq, "tokens": todayTok, "cost": todayCost},
		"month": gin.H{"requests": monthReq, "tokens": monthTok, "cost": monthCost},
	})
}

// UsageStats GET /api/v1/usage/stats?from&to&group=day|model
func (h *Handler) UsageStats(c *gin.Context) {
	u, _ := userFromContext(c)
	from := c.DefaultQuery("from", time.Now().Add(-30*24*time.Hour).Format("2006-01-02"))
	to := c.DefaultQuery("to", time.Now().Format("2006-01-02"))
	group := c.DefaultQuery("group", "day")

	q := h.a.DB.Model(&store.UsageDaily{}).Where("user_id = ? AND date BETWEEN ? AND ?", u.ID, from, to)
	out := make([]gin.H, 0, 64)
	if group == "model" {
		var rows []struct {
			ModelID  uint64
			Requests int64
			Tokens   int64
			Cost     float64
		}
		q.Select("model_id, SUM(requests) requests, SUM(input_tokens+output_tokens+cache_read_tokens) tokens, SUM(cost) cost").
			Group("model_id").Scan(&rows)
		for _, r := range rows {
			var m store.Model
			name := strconv.FormatUint(r.ModelID, 10)
			if h.a.DB.First(&m, r.ModelID).Error == nil {
				name = m.Name
			}
			out = append(out, gin.H{"model": name, "requests": r.Requests, "tokens": r.Tokens, "cost": r.Cost})
		}
	} else {
		var rows []struct {
			Date     string
			Requests int64
			Tokens   int64
			Cost     float64
		}
		q.Select("date, SUM(requests) requests, SUM(input_tokens+output_tokens+cache_read_tokens) tokens, SUM(cost) cost").
			Group("date").Order("date").Scan(&rows)
		for _, r := range rows {
			out = append(out, gin.H{"date": r.Date, "requests": r.Requests, "tokens": r.Tokens, "cost": r.Cost})
		}
	}
	resp.OK(c, gin.H{"items": out})
}

// UsageLogs GET /api/v1/usage/logs?from&to&page&page_size&model
func (h *Handler) UsageLogs(c *gin.Context) {
	u, _ := userFromContext(c)
	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	size, _ := strconv.Atoi(c.DefaultQuery("page_size", "20"))
	if page < 1 {
		page = 1
	}
	if size < 1 || size > 100 {
		size = 20
	}
	q := h.a.DB.Model(&store.UsageLog{}).Where("user_id = ?", u.ID)
	if from := c.Query("from"); from != "" {
		q = q.Where("created_at >= ?", from+" 00:00:00")
	}
	if to := c.Query("to"); to != "" {
		q = q.Where("created_at <= ?", to+" 23:59:59")
	}
	if model := c.Query("model"); model != "" {
		q = q.Where("model_name = ?", model)
	}
	var total int64
	q.Count(&total)
	var logs []store.UsageLog
	q.Order("id DESC").Offset((page - 1) * size).Limit(size).Find(&logs)
	out := make([]gin.H, 0, len(logs))
	for _, l := range logs {
		out = append(out, gin.H{
			"id": l.ID, "request_id": l.RequestID, "model": l.ModelName, "protocol": l.Protocol,
			"input_tokens": l.InputTokens, "output_tokens": l.OutputTokens,
			"cache_read_tokens": l.CacheReadTokens, "cost": l.Cost,
			"latency_ms": l.LatencyMS, "status": l.Status, "error_code": l.ErrorCode,
			"created_at": l.CreatedAt,
		})
	}
	resp.OK(c, gin.H{"items": out, "total": total, "page": page, "page_size": size})
}