package server

import (
	"database/sql"
	"net/http"
	"strconv"
	"time"
)

type artifactUsageRow struct {
	CreatedAt        time.Time `json:"created_at"`
	TaskID           string    `json:"task_id,omitempty"`
	Kind             string    `json:"kind"`
	Model            string    `json:"model"`
	Endpoint         string    `json:"endpoint"`
	Size             string    `json:"size"`
	Quality          string    `json:"quality"`
	RequestID        string    `json:"request_id,omitempty"`
	InputTokens      int64     `json:"input_tokens"`
	InputTextTokens  int64     `json:"input_text_tokens"`
	InputImageTokens int64     `json:"input_image_tokens"`
	OutputTokens     int64     `json:"output_tokens"`
	TotalTokens      int64     `json:"total_tokens"`
	EstimatedCostUSD *float64  `json:"estimated_cost_usd,omitempty"`
	PricingBasis     string    `json:"pricing_basis,omitempty"`
}

func (s *Server) adminArtifactUsage(w http.ResponseWriter, r *http.Request) {
	now := time.Now().UTC()
	dayStartMS := time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, time.UTC).UnixMilli()
	if raw := r.URL.Query().Get("day_start_ms"); raw != "" {
		if v, err := strconv.ParseInt(raw, 10, 64); err == nil {
			// Accept a browser-local midnight in a reasonable window. This lets the
			// "today" KPI follow the admin's local calendar day without adding a
			// timezone setting to the server.
			candidate := time.UnixMilli(v).UTC()
			if candidate.After(now.Add(-48*time.Hour)) && candidate.Before(now.Add(24*time.Hour)) {
				dayStartMS = v
			}
		}
	}

	var todayCalls, todayCards, todayPriced int64
	var todayCost float64
	_ = s.store.DB.QueryRowContext(r.Context(), `SELECT count(*),
		COALESCE(sum(CASE WHEN kind='artifact' THEN 1 ELSE 0 END),0),
		COALESCE(sum(CASE WHEN estimated_cost_usd IS NOT NULL THEN 1 ELSE 0 END),0),
		COALESCE(sum(estimated_cost_usd),0)
		FROM artifact_api_usage WHERE created_at>=?`, dayStartMS).Scan(&todayCalls, &todayCards, &todayPriced, &todayCost)

	var cardCalls, pricedCardCalls int64
	var totalCardCost, avgCardCost float64
	var inputTokens, inputTextTokens, inputImageTokens, outputTokens, totalTokens int64
	_ = s.store.DB.QueryRowContext(r.Context(), `SELECT count(*),count(estimated_cost_usd),
		COALESCE(sum(estimated_cost_usd),0),COALESCE(avg(estimated_cost_usd),0),
		COALESCE(sum(input_tokens),0),COALESCE(sum(input_text_tokens),0),COALESCE(sum(input_image_tokens),0),
		COALESCE(sum(output_tokens),0),COALESCE(sum(total_tokens),0)
		FROM artifact_api_usage WHERE kind='artifact'`).Scan(
		&cardCalls, &pricedCardCalls, &totalCardCost, &avgCardCost,
		&inputTokens, &inputTextTokens, &inputImageTokens, &outputTokens, &totalTokens)

	var anchorCalls int64
	var anchorCost float64
	_ = s.store.DB.QueryRowContext(r.Context(), `SELECT count(*),COALESCE(sum(estimated_cost_usd),0)
		FROM artifact_api_usage WHERE kind='character_anchor'`).Scan(&anchorCalls, &anchorCost)

	var rollingCalls1H, rollingCalls24H int64
	var rollingCost24H float64
	oneHourMS := now.Add(-time.Hour).UnixMilli()
	twentyFourHoursMS := now.Add(-24 * time.Hour).UnixMilli()
	_ = s.store.DB.QueryRowContext(r.Context(), `SELECT
		COALESCE(sum(CASE WHEN created_at>=? THEN 1 ELSE 0 END),0),
		count(*),COALESCE(sum(estimated_cost_usd),0)
		FROM artifact_api_usage WHERE provider='openai' AND created_at>=?`, oneHourMS, twentyFourHoursMS).Scan(&rollingCalls1H, &rollingCalls24H, &rollingCost24H)
	cfg := s.settings.Get()
	circuitBlocked := (cfg.OpenAIMaxCalls1H > 0 && rollingCalls1H >= int64(cfg.OpenAIMaxCalls1H)) ||
		(cfg.OpenAIMaxCalls24H > 0 && rollingCalls24H >= int64(cfg.OpenAIMaxCalls24H)) ||
		(cfg.OpenAIMaxCost24HUSD > 0 && rollingCost24H+cfg.OpenAIBudgetReserveUSD > cfg.OpenAIMaxCost24HUSD)

	recent := make([]artifactUsageRow, 0, 20)
	rows, err := s.store.DB.QueryContext(r.Context(), `SELECT created_at,task_id,kind,model,endpoint,size,quality,request_id,
		input_tokens,input_text_tokens,input_image_tokens,output_tokens,total_tokens,estimated_cost_usd,pricing_basis
		FROM artifact_api_usage ORDER BY created_at DESC,id DESC LIMIT 20`)
	if err == nil {
		defer rows.Close()
		for rows.Next() {
			var createdMS int64
			var taskID, requestID sql.NullString
			var cost sql.NullFloat64
			var row artifactUsageRow
			if err := rows.Scan(&createdMS, &taskID, &row.Kind, &row.Model, &row.Endpoint, &row.Size, &row.Quality, &requestID,
				&row.InputTokens, &row.InputTextTokens, &row.InputImageTokens, &row.OutputTokens, &row.TotalTokens, &cost, &row.PricingBasis); err != nil {
				continue
			}
			row.CreatedAt = time.UnixMilli(createdMS).UTC()
			if taskID.Valid {
				row.TaskID = taskID.String
			}
			if requestID.Valid {
				row.RequestID = requestID.String
			}
			if cost.Valid {
				v := cost.Float64
				row.EstimatedCostUSD = &v
			}
			recent = append(recent, row)
		}
	}

	jsonOut(w, 200, map[string]any{
		"day_start":               time.UnixMilli(dayStartMS).UTC(),
		"today_calls":             todayCalls,
		"today_cards":             todayCards,
		"today_priced_calls":      todayPriced,
		"today_cost_usd":          todayCost,
		"card_generations":        cardCalls,
		"priced_card_generations": pricedCardCalls,
		"total_card_cost_usd":     totalCardCost,
		"avg_card_cost_usd":       avgCardCost,
		"cost_per_1000_usd":       avgCardCost * 1000,
		"anchor_generations":      anchorCalls,
		"anchor_cost_usd":         anchorCost,
		"card_usage": map[string]int64{
			"input_tokens":       inputTokens,
			"input_text_tokens":  inputTextTokens,
			"input_image_tokens": inputImageTokens,
			"output_tokens":      outputTokens,
			"total_tokens":       totalTokens,
		},
		"circuit_breaker": map[string]any{
			"blocked":              circuitBlocked,
			"calls_1h":             rollingCalls1H,
			"calls_24h":            rollingCalls24H,
			"cost_24h_usd":         rollingCost24H,
			"max_calls_1h":         cfg.OpenAIMaxCalls1H,
			"max_calls_24h":        cfg.OpenAIMaxCalls24H,
			"max_cost_24h_usd":     cfg.OpenAIMaxCost24HUSD,
			"reserve_per_call_usd": cfg.OpenAIBudgetReserveUSD,
		},
		"cost_method": "estimated from provider-reported token usage using pinned OpenAI standard public token rates; not invoice reconciliation",
		"recent":      recent,
	})
}