package handlers

import (
	"context"
	"fmt"
	"net/http"
	"strconv"

	"git.haelnorr.com/h/golib/hws"
	"git.haelnorr.com/h/oslstats/internal/db"
	"git.haelnorr.com/h/oslstats/internal/throw"
	playersview "git.haelnorr.com/h/oslstats/internal/view/playersview"
	"github.com/pkg/errors"
	"github.com/uptrace/bun"
)

// ProfileRedirect redirects the authenticated user to their own player page.
func ProfileRedirect(
	s *hws.Server,
) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		user := db.CurrentUser(r.Context())
		if user == nil {
			throw.Unauthorized(s, w, r, "You must be logged in to view your profile", errors.New("user not authenticated"))
			return
		}
		if user.Player == nil {
			throw.InternalServiceError(s, w, r, "Player profile not found", errors.New("user has no linked player"))
			return
		}
		http.Redirect(w, r, fmt.Sprintf("/players/%d", user.Player.ID), http.StatusSeeOther)
	})
}

// resolvePlayerAndOwner is a helper that resolves the player from the URL path
// and determines if the current user is the owner of the player.
// Returns false from the outer handler if resolution failed (404 already thrown).
func resolvePlayerAndOwner(
	s *hws.Server,
	conn *db.DB,
	w http.ResponseWriter,
	r *http.Request,
) (player *db.Player, isOwner bool, ok bool) {
	playerIDStr := r.PathValue("player_id")
	playerID, err := strconv.Atoi(playerIDStr)
	if err != nil {
		throw.NotFound(s, w, r, r.URL.Path)
		return nil, false, false
	}

	if ok := conn.WithReadTx(s, w, r, func(ctx context.Context, tx bun.Tx) (bool, error) {
		var err error
		player, err = db.GetPlayer(ctx, tx, playerID)
		if err != nil {
			if db.IsBadRequest(err) {
				throw.NotFound(s, w, r, r.URL.Path)
				return false, nil
			}
			return false, errors.Wrap(err, "db.GetPlayer")
		}

		user := db.CurrentUser(ctx)
		if user != nil && player.UserID != nil && *player.UserID == user.ID {
			isOwner = true
		}

		return true, nil
	}); !ok {
		return nil, false, false
	}

	// If player has no SlapID and viewer is not the owner, show 404
	if player.SlapID == nil && !isOwner {
		throw.NotFound(s, w, r, r.URL.Path)
		return nil, false, false
	}

	return player, isOwner, true
}

// PlayerViewStats renders the player profile page with the stats tab active.
// GET renders the full page layout. POST renders just the tab content.
func PlayerViewStats(
	s *hws.Server,
	conn *db.DB,
) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		player, isOwner, ok := resolvePlayerAndOwner(s, conn, w, r)
		if !ok {
			return
		}

		var stats *db.PlayerAllTimeStats
		var seasons []*db.Season
		var teams []*db.Team

		if ok := conn.WithReadTx(s, w, r, func(ctx context.Context, tx bun.Tx) (bool, error) {
			var err error
			stats, err = db.GetPlayerAllTimeStats(ctx, tx, player.ID)
			if err != nil {
				return false, errors.Wrap(err, "db.GetPlayerAllTimeStats")
			}
			seasons, err = db.GetPlayerSeasonsList(ctx, tx, player.ID)
			if err != nil {
				return false, errors.Wrap(err, "db.GetPlayerSeasonsList")
			}
			teams, err = db.GetPlayerTeamsList(ctx, tx, player.ID)
			if err != nil {
				return false, errors.Wrap(err, "db.GetPlayerTeamsList")
			}
			return true, nil
		}); !ok {
			return
		}

		if r.Method == "GET" {
			renderSafely(playersview.PlayerStatsPage(player, isOwner, stats, seasons, teams), s, r, w)
		} else {
			renderSafely(playersview.PlayerStatsTab(player, stats, seasons, teams, "", 0), s, r, w)
		}
	})
}

// PlayerViewTeams renders the teams tab of the player profile page.
func PlayerViewTeams(
	s *hws.Server,
	conn *db.DB,
) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		player, isOwner, ok := resolvePlayerAndOwner(s, conn, w, r)
		if !ok {
			return
		}

		var teamInfos []*db.PlayerTeamInfo

		if ok := conn.WithReadTx(s, w, r, func(ctx context.Context, tx bun.Tx) (bool, error) {
			var err error
			teamInfos, err = db.GetPlayerTeams(ctx, tx, player.ID)
			if err != nil {
				return false, errors.Wrap(err, "db.GetPlayerTeams")
			}
			return true, nil
		}); !ok {
			return
		}

		if r.Method == "GET" {
			renderSafely(playersview.PlayerTeamsPage(player, isOwner, teamInfos), s, r, w)
		} else {
			renderSafely(playersview.PlayerTeamsTab(teamInfos), s, r, w)
		}
	})
}

// PlayerViewSeasons renders the seasons tab of the player profile page.
func PlayerViewSeasons(
	s *hws.Server,
	conn *db.DB,
) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		player, isOwner, ok := resolvePlayerAndOwner(s, conn, w, r)
		if !ok {
			return
		}

		var seasonInfos []*db.PlayerSeasonInfo

		if ok := conn.WithReadTx(s, w, r, func(ctx context.Context, tx bun.Tx) (bool, error) {
			var err error
			seasonInfos, err = db.GetPlayerSeasons(ctx, tx, player.ID)
			if err != nil {
				return false, errors.Wrap(err, "db.GetPlayerSeasons")
			}
			return true, nil
		}); !ok {
			return
		}

		if r.Method == "GET" {
			renderSafely(playersview.PlayerSeasonsPage(player, isOwner, seasonInfos), s, r, w)
		} else {
			renderSafely(playersview.PlayerSeasonsTab(seasonInfos), s, r, w)
		}
	})
}