package handlers

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

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

// redirectDraftSeasonLeague checks if a season is a draft type and redirects
// GET requests from /seasons/{short}/leagues/Draft/{tab} to /seasons/{short}/{tab}.
// Returns true if a redirect was issued (caller should return early).
// POST requests are not redirected since they are HTMX partial content requests.
func redirectDraftSeasonLeague(season *db.Season, tab string, w http.ResponseWriter, r *http.Request) bool {
	if r.Method == "GET" && season.Type == db.SeasonTypeDraft.String() {
		redirectURL := fmt.Sprintf("/seasons/%s/%s", season.ShortName, tab)
		http.Redirect(w, r, redirectURL, http.StatusSeeOther)
		return true
	}
	return false
}

// DraftSeasonTabPage handles GET requests for draft season tab pages at
// /seasons/{season_short_name}/{tab}. It renders the full DraftSeasonDetailPage
// with the appropriate tab content pre-rendered.
func DraftSeasonTabPage(
	s *hws.Server,
	conn *db.DB,
	tab string,
) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		seasonStr := r.PathValue("season_short_name")

		var season *db.Season
		var league *db.League
		var teams []*db.Team
		var availableTeams []*db.Team
		var fixtures []*db.Fixture

		if ok := conn.WithReadTx(s, w, r, func(ctx context.Context, tx bun.Tx) (bool, error) {
			var err error

			// Verify this is a draft season
			season, err = db.GetSeason(ctx, tx, seasonStr)
			if err != nil {
				if db.IsBadRequest(err) {
					throw.NotFound(s, w, r, r.URL.Path)
					return false, nil
				}
				return false, errors.Wrap(err, "db.GetSeason")
			}

			if season.Type != db.SeasonTypeDraft.String() {
				throw.NotFound(s, w, r, r.URL.Path)
				return false, nil
			}

			// Fetch the Draft league and teams
			season, league, teams, err = db.GetSeasonLeague(ctx, tx, seasonStr, "Draft")
			if err != nil {
				return false, errors.Wrap(err, "db.GetSeasonLeague")
			}

			// Fetch tab-specific data
			switch tab {
			case "teams":
				availableTeams, err = db.GetList[db.Team](tx).
					Join("LEFT JOIN team_participations tp ON tp.team_id = t.id").
					Where("NOT tp.season_id = ? OR tp.season_id IS NULL", season.ID).
					GetAll(ctx)
				if err != nil {
					return false, errors.Wrap(err, "db.GetList[Team]")
				}
			case "fixtures":
				season, league, fixtures, err = db.GetFixtures(ctx, tx, seasonStr, "Draft")
				if err != nil {
					return false, errors.Wrap(err, "db.GetFixtures")
				}
			}

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

		renderSafely(seasonsview.DraftSeasonDetailPage(
			season, league, teams, availableTeams, fixtures, tab,
		), s, r, w)
	})
}