package server

import (
	"net/http"
	"strconv"

	"music-server/internal/backend"
	"music-server/internal/logging"

	"github.com/labstack/echo/v5"
	"go.uber.org/zap"
)

// StatisticsHandler handles statistics-related HTTP requests
type StatisticsHandler struct {
	statsBackend *backend.StatisticsHandler
}

// NewStatisticsHandler creates a new StatisticsHandler
func NewStatisticsHandler() *StatisticsHandler {
	return &StatisticsHandler{
		statsBackend: backend.NewStatisticsHandler(),
	}
}

// GetMostPlayedSoundtracks returns top N most played soundtracks with songs
// GET /api/v1/statistics/soundtracks/most-played
//
//	@Summary		Get most played soundtracks
//	@Description	Returns the top N most played soundtracks with their songs
//	@Tags			statistics
//	@Accept		json
//	@Produce		json
//	@Param			limit	query	int	false	"Number of results (default: 10)"
//	@Success		200	{array}	backend.SoundtrackWithSongs
//	@Failure		400	{object}	map[string]string
//	@Failure		500	{object}	map[string]string
//	@Router		/api/v1/statistics/soundtracks/most-played [get]
func (h *StatisticsHandler) GetMostPlayedSoundtracks(ctx *echo.Context) error {
	limit := 10 // default
	limitStr := ctx.QueryParam("limit")
	if limitStr != "" {
		var err error
		limit, err = strconv.Atoi(limitStr)
		if err != nil || limit <= 0 {
			return ctx.JSON(http.StatusBadRequest, map[string]string{"error": "Invalid limit parameter"})
		}
		// Cap at 100 for performance
		if limit > 100 {
			limit = 100
		}
	}

	soundtracks, err := h.statsBackend.GetMostPlayedSoundtracksWithSongs(int32(limit))
	if err != nil {
		logging.GetLogger().Error("Failed to get most played soundtracks", zap.String("error", err.Error()))
		return ctx.JSON(http.StatusInternalServerError, map[string]string{"error": "Failed to get statistics"})
	}
	return ctx.JSON(http.StatusOK, soundtracks)
}

// GetLeastPlayedSoundtracks returns top N least played soundtracks with songs
// GET /api/v1/statistics/soundtracks/least-played
//
//	@Summary		Get least played soundtracks
//	@Description	Returns the top N least played soundtracks with their songs
//	@Tags			statistics
//	@Accept		json
//	@Produce		json
//	@Param			limit	query	int	false	"Number of results (default: 10)"
//	@Success		200	{array}	backend.SoundtrackWithSongs
//	@Failure		400	{object}	map[string]string
//	@Failure		500	{object}	map[string]string
//	@Router		/api/v1/statistics/soundtracks/least-played [get]
func (h *StatisticsHandler) GetLeastPlayedSoundtracks(ctx *echo.Context) error {
	limit := 10
	limitStr := ctx.QueryParam("limit")
	if limitStr != "" {
		var err error
		limit, err = strconv.Atoi(limitStr)
		if err != nil || limit <= 0 {
			return ctx.JSON(http.StatusBadRequest, map[string]string{"error": "Invalid limit parameter"})
		}
		if limit > 100 {
			limit = 100
		}
	}

	soundtracks, err := h.statsBackend.GetLeastPlayedSoundtracksWithSongs(int32(limit))
	if err != nil {
		logging.GetLogger().Error("Failed to get least played soundtracks", zap.String("error", err.Error()))
		return ctx.JSON(http.StatusInternalServerError, map[string]string{"error": "Failed to get statistics"})
	}
	return ctx.JSON(http.StatusOK, soundtracks)
}

// GetMostPlayedSongs returns top N most played songs with soundtrack info
// GET /api/v1/statistics/songs/most-played
//
//	@Summary		Get most played songs
//	@Description	Returns the top N most played songs with their soundtrack info
//	@Tags			statistics
//	@Accept		json
//	@Produce		json
//	@Param			limit	query	int	false	"Number of results (default: 10)"
//	@Success		200	{array}	backend.SongInfoForStats
//	@Failure		400	{object}	map[string]string
//	@Failure		500	{object}	map[string]string
//	@Router		/api/v1/statistics/songs/most-played [get]
func (h *StatisticsHandler) GetMostPlayedSongs(ctx *echo.Context) error {
	limit := 10
	limitStr := ctx.QueryParam("limit")
	if limitStr != "" {
		var err error
		limit, err = strconv.Atoi(limitStr)
		if err != nil || limit <= 0 {
			return ctx.JSON(http.StatusBadRequest, map[string]string{"error": "Invalid limit parameter"})
		}
		if limit > 100 {
			limit = 100
		}
	}

	songs, err := h.statsBackend.GetMostPlayedSongsWithSoundtrack(int32(limit))
	if err != nil {
		logging.GetLogger().Error("Failed to get most played songs", zap.String("error", err.Error()))
		return ctx.JSON(http.StatusInternalServerError, map[string]string{"error": "Failed to get statistics"})
	}
	return ctx.JSON(http.StatusOK, songs)
}

// GetLeastPlayedSongs returns top N least played songs with soundtrack info
// GET /api/v1/statistics/songs/least-played
//
//	@Summary		Get least played songs
//	@Description	Returns the top N least played songs with their soundtrack info
//	@Tags			statistics
//	@Accept		json
//	@Produce		json
//	@Param			limit	query	int	false	"Number of results (default: 10)"
//	@Success		200	{array}	backend.SongInfoForStats
//	@Failure		400	{object}	map[string]string
//	@Failure		500	{object}	map[string]string
//	@Router		/api/v1/statistics/songs/least-played [get]
func (h *StatisticsHandler) GetLeastPlayedSongs(ctx *echo.Context) error {
	limit := 10
	limitStr := ctx.QueryParam("limit")
	if limitStr != "" {
		var err error
		limit, err = strconv.Atoi(limitStr)
		if err != nil || limit <= 0 {
			return ctx.JSON(http.StatusBadRequest, map[string]string{"error": "Invalid limit parameter"})
		}
		if limit > 100 {
			limit = 100
		}
	}

	songs, err := h.statsBackend.GetLeastPlayedSongsWithSoundtrack(int32(limit))
	if err != nil {
		logging.GetLogger().Error("Failed to get least played songs", zap.String("error", err.Error()))
		return ctx.JSON(http.StatusInternalServerError, map[string]string{"error": "Failed to get statistics"})
	}
	return ctx.JSON(http.StatusOK, songs)
}

// GetNeverPlayedSoundtracks returns soundtracks that have never been played
// GET /api/v1/statistics/soundtracks/never-played
//
//	@Summary		Get never played soundtracks
//	@Description	Returns all soundtracks that have never been played (times_played = 0)
//	@Tags			statistics
//	@Accept		json
//	@Produce		json
//	@Success		200	{array}	backend.SoundtrackWithSongs
//	@Failure		500	{object}	map[string]string
//	@Router		/api/v1/statistics/soundtracks/never-played [get]
func (h *StatisticsHandler) GetNeverPlayedSoundtracks(ctx *echo.Context) error {
	soundtracks, err := h.statsBackend.GetNeverPlayedSoundtracks()
	if err != nil {
		logging.GetLogger().Error("Failed to get never played soundtracks", zap.String("error", err.Error()))
		return ctx.JSON(http.StatusInternalServerError, map[string]string{"error": "Failed to get statistics"})
	}
	return ctx.JSON(http.StatusOK, soundtracks)
}

// GetLastPlayedSoundtracks returns most recently played soundtracks
// GET /api/v1/statistics/soundtracks/last-played
//
//	@Summary		Get last played soundtracks
//	@Description	Returns the most recently played soundtracks
//	@Tags			statistics
//	@Accept		json
//	@Produce		json
//	@Param			limit	query	int	false	"Number of results (default: 10)"
//	@Success		200	{array}	backend.SoundtrackWithSongs
//	@Failure		400	{object}	map[string]string
//	@Failure		500	{object}	map[string]string
//	@Router		/api/v1/statistics/soundtracks/last-played [get]
func (h *StatisticsHandler) GetLastPlayedSoundtracks(ctx *echo.Context) error {
	limit := 10
	limitStr := ctx.QueryParam("limit")
	if limitStr != "" {
		var err error
		limit, err = strconv.Atoi(limitStr)
		if err != nil || limit <= 0 {
			return ctx.JSON(http.StatusBadRequest, map[string]string{"error": "Invalid limit parameter"})
		}
		if limit > 100 {
			limit = 100
		}
	}

	soundtracks, err := h.statsBackend.GetLastPlayedSoundtracks(int32(limit))
	if err != nil {
		logging.GetLogger().Error("Failed to get last played soundtracks", zap.String("error", err.Error()))
		return ctx.JSON(http.StatusInternalServerError, map[string]string{"error": "Failed to get statistics"})
	}
	return ctx.JSON(http.StatusOK, soundtracks)
}

// GetOldestPlayedSoundtracks returns least recently played soundtracks
// GET /api/v1/statistics/soundtracks/oldest-played
//
//	@Summary		Get oldest played soundtracks
//	@Description	Returns the least recently played soundtracks (that have been played at least once)
//	@Tags			statistics
//	@Accept		json
//	@Produce		json
//	@Param			limit	query	int	false	"Number of results (default: 10)"
//	@Success		200	{array}	backend.SoundtrackWithSongs
//	@Failure		400	{object}	map[string]string
//	@Failure		500	{object}	map[string]string
//	@Router		/api/v1/statistics/soundtracks/oldest-played [get]
func (h *StatisticsHandler) GetOldestPlayedSoundtracks(ctx *echo.Context) error {
	limit := 10
	limitStr := ctx.QueryParam("limit")
	if limitStr != "" {
		var err error
		limit, err = strconv.Atoi(limitStr)
		if err != nil || limit <= 0 {
			return ctx.JSON(http.StatusBadRequest, map[string]string{"error": "Invalid limit parameter"})
		}
		if limit > 100 {
			limit = 100
		}
	}

	soundtracks, err := h.statsBackend.GetOldestPlayedSoundtracks(int32(limit))
	if err != nil {
		logging.GetLogger().Error("Failed to get oldest played soundtracks", zap.String("error", err.Error()))
		return ctx.JSON(http.StatusInternalServerError, map[string]string{"error": "Failed to get statistics"})
	}
	return ctx.JSON(http.StatusOK, soundtracks)
}

// GetStatisticsSummary returns overall statistics
// GET /api/v1/statistics/summary
//
//	@Summary		Get statistics summary
//	@Description	Returns overall statistics about the music library
//	@Tags			statistics
//	@Accept		json
//	@Produce		json
//	@Success		200	{object}	backend.StatisticsSummary
//	@Failure		500	{object}	map[string]string
//	@Router		/api/v1/statistics/summary [get]
func (h *StatisticsHandler) GetStatisticsSummary(ctx *echo.Context) error {
	summary, err := h.statsBackend.GetStatisticsSummary()
	if err != nil {
		logging.GetLogger().Error("Failed to get statistics summary", zap.String("error", err.Error()))
		return ctx.JSON(http.StatusInternalServerError, map[string]string{"error": "Failed to get statistics"})
	}
	return ctx.JSON(http.StatusOK, summary)
}