package handlers

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

	"github.com/labstack/echo/v4"
	"github.com/tas/horchposten/models"
)

// Leaderboard handles GET /api/analytics/leaderboard/
func Leaderboard(db *sql.DB) echo.HandlerFunc {
	return func(c echo.Context) error {
		limit := 20
		if l := c.QueryParam("limit"); l != "" {
			parsed, err := strconv.Atoi(l)
			if err == nil && parsed > 0 {
				limit = parsed
			}
		}
		if limit > 100 {
			limit = 100
		}

		rows, err := db.Query(
			`SELECT p.client_id, h.score, h.achieved_at
			FROM high_scores h
			JOIN players p ON p.id = h.player_id
			ORDER BY h.score DESC
			LIMIT ?`,
			limit,
		)
		if err != nil {
			return c.JSON(http.StatusInternalServerError, echo.Map{"error": "database error"})
		}
		defer rows.Close()

		entries := make([]models.LeaderboardEntry, 0)
		for rows.Next() {
			var e models.LeaderboardEntry
			var achievedAt string
			if err := rows.Scan(&e.ClientID, &e.Score, &achievedAt); err != nil {
				return c.JSON(http.StatusInternalServerError, echo.Map{"error": "scan error"})
			}
			e.AchievedAt = parseTime(achievedAt)
			entries = append(entries, e)
		}

		return c.JSON(http.StatusOK, echo.Map{"leaderboard": entries})
	}
}