package handler

import (
	"context"
	"encoding/json"
	"net/http"
	"strings"
	"time"
	"vctp/internal/tasks"
)

// SnapshotAggregateForce forces regeneration of a daily or monthly summary table.
// @Summary Force snapshot aggregation
// @Description Forces regeneration of a daily or monthly summary table for a specified date or month.
// @Tags snapshots
// @Produce json
// @Param type query string true "Aggregation type: daily or monthly"
// @Param date query string true "Daily date (YYYY-MM-DD) or monthly date (YYYY-MM)"
// @Success 200 {object} map[string]string "Aggregation complete"
// @Failure 400 {object} map[string]string "Invalid request"
// @Failure 500 {object} map[string]string "Server error"
// @Router /api/snapshots/aggregate [post]
func (h *Handler) SnapshotAggregateForce(w http.ResponseWriter, r *http.Request) {
	snapshotType := strings.ToLower(strings.TrimSpace(r.URL.Query().Get("type")))
	dateValue := strings.TrimSpace(r.URL.Query().Get("date"))
	startedAt := time.Now()
	loc := time.Now().Location()

	if snapshotType == "" || dateValue == "" {
		h.Logger.Warn("Snapshot aggregation request missing parameters",
			"type", snapshotType,
			"date", dateValue,
		)
		writeJSONError(w, http.StatusBadRequest, "type and date are required")
		return
	}

	ctx := context.Background()
	ct := &tasks.CronTask{
		Logger:   h.Logger,
		Database: h.Database,
		Settings: h.Settings,
	}

	switch snapshotType {
	case "daily":
		parsed, err := time.ParseInLocation("2006-01-02", dateValue, loc)
		if err != nil {
			h.Logger.Warn("Snapshot aggregation invalid daily date format", "date", dateValue)
			writeJSONError(w, http.StatusBadRequest, "date must be YYYY-MM-DD")
			return
		}
		h.Logger.Info("Starting daily snapshot aggregation", "date", parsed.Format("2006-01-02"), "force", true)
		if err := ct.AggregateDailySummary(ctx, parsed, true); err != nil {
			h.Logger.Error("Daily snapshot aggregation failed", "date", parsed.Format("2006-01-02"), "error", err)
			writeJSONError(w, http.StatusInternalServerError, err.Error())
			return
		}
	case "monthly":
		parsed, err := time.ParseInLocation("2006-01", dateValue, loc)
		if err != nil {
			h.Logger.Warn("Snapshot aggregation invalid monthly date format", "date", dateValue)
			writeJSONError(w, http.StatusBadRequest, "date must be YYYY-MM")
			return
		}
		h.Logger.Info("Starting monthly snapshot aggregation", "date", parsed.Format("2006-01"), "force", true)
		if err := ct.AggregateMonthlySummary(ctx, parsed, true); err != nil {
			h.Logger.Error("Monthly snapshot aggregation failed", "date", parsed.Format("2006-01"), "error", err)
			writeJSONError(w, http.StatusInternalServerError, err.Error())
			return
		}
	default:
		h.Logger.Warn("Snapshot aggregation invalid type", "type", snapshotType)
		writeJSONError(w, http.StatusBadRequest, "type must be daily or monthly")
		return
	}

	h.Logger.Info("Snapshot aggregation completed",
		"type", snapshotType,
		"date", dateValue,
		"duration", time.Since(startedAt),
	)
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(http.StatusOK)
	json.NewEncoder(w).Encode(map[string]string{
		"status": "OK",
	})
}

func writeJSONError(w http.ResponseWriter, status int, message string) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	json.NewEncoder(w).Encode(map[string]string{
		"status":  "ERROR",
		"message": message,
	})
}