package main

import (
	"context"
	"encoding/csv"
	"gegio-ue1/model"
	"os"
	"slices"
	"strconv"

	"github.com/wailsapp/wails/v2/pkg/runtime"
	"gorm.io/gorm"
)

// App struct
type App struct {
	ctx context.Context
	db  *gorm.DB
}

// NewApp creates a new App application struct
func NewApp(db *gorm.DB) *App {
	return &App{
		db: db,
	}
}

// startup is called when the app starts. The context is saved
// so we can call the runtime methods
func (a *App) startup(ctx context.Context) {
	a.ctx = ctx
}

func (a *App) GetGames() (gs []model.Game, err error) {
	err = a.db.Find(&gs).Error
	return

}

func (a *App) GetTournaments() (ts []model.Tournament, err error) {
	err = a.db.Preload("Game").Preload("WinnerParticipant").Find(&ts).Error
	return
}

func (a *App) GetTournament(id int) (t model.Tournament, err error) {
	err = a.db.Preload("Game").Preload("Participants").Preload("Matches").First(&t, id).Error
	return
}
func (a *App) SaveTournament(t model.Tournament) error {
	err := a.db.Save(&t).Error
	return err
}
func (a *App) FillRandom(t model.Tournament) {
	for range t.Size - len(t.Participants) {
		t.Participants = append(t.Participants, &model.Participant{
			Name:        model.RandomName(),
			IsTemporary: true,
			IsTeam:      true,
		})
	}
	a.db.Save(&t.Participants)
	a.db.Save(&t)

}

func (a *App) StartTournament(t model.Tournament) {
	t.TournamentState = 1
	a.SaveTournament(t)
	t, _ = a.GetTournament(int(t.ID))
	matches := make([]model.Match, 0, len(t.Participants)/2)
	for i := range len(t.Participants) / 2 {
		matches = append(matches, model.Match{
			TournamentID:   t.ID,
			Stage:          1,
			Order:          i,
			Participant1ID: t.Participants[i].ID,
			Participant2ID: t.Participants[i+len(t.Participants)/2].ID,
		})
	}
	if len(t.Participants)%2 != 0 {
		matches = append(matches, model.Match{
			TournamentID:   t.ID,
			Stage:          1,
			Order:          len(t.Participants)/2 + 1,
			Participant1ID: t.Participants[len(t.Participants)-1].ID,
			Participant2ID: t.Participants[len(t.Participants)-1].ID,
		})
	}
	a.db.Save(matches)
}

func (a *App) ExportTournament(t model.Tournament) {
	dirname, _ := os.UserHomeDir()
	str, err := runtime.SaveFileDialog(a.ctx, runtime.SaveDialogOptions{DefaultDirectory: dirname, DefaultFilename: "tournament.csv"})
	if err != nil {
		panic(err)
	}
	file, err := os.Create(str)
	if err != nil {
		panic(err)
	}
	defer file.Close()
	// Create a CSV writer
	writer := csv.NewWriter(file)
	defer writer.Flush()

	var matches []model.Match

	a.db.Where("tournament_id = ?", t.ID).Order("stage ASC").Order("`order` ASC").Preload("Participant1").Preload("Participant2").Preload("WinnerParticipant").Find(&matches)

	// Write header
	header := []string{"Stage", "Order", "Winner", "Looser"}
	if err := writer.Write(header); err != nil {
		panic(err)
	}

	for _, m := range matches {
		record := []string{strconv.Itoa(m.Stage), strconv.Itoa(m.Order), m.WinnerParticipant.Name}
		if m.WinnerParticipantID == m.Participant1ID {
			record = append(record, m.Participant2.Name)
		} else {

			record = append(record, m.Participant1.Name)
		}
		if err := writer.Write(record); err != nil {
			panic(err)
		}
	}

}

func (a *App) GetParticipants() (ps []model.Participant, err error) {
	err = a.db.Find(&ps).Error
	return
}
func (a *App) SaveParticipant(p model.Participant) error {
	return a.db.Save(&p).Error
}
func (a *App) DeleteParticipat(p model.Participant) {
	a.db.Delete(&p)
}
func (a *App) RemoveParticipantFromTournament(p model.Participant, t model.Tournament) {
	if p.IsTemporary {
		a.db.Delete(&p)
		return
	}
	a.db.Model(&t).Association("Participants").Delete(&p)
}

func (a *App) GetMatches(tID uint) [][]model.Match {
	rawMatches := make([]model.Match, 0)
	a.db.Preload("Participant1").Preload("Participant2").Preload("WinnerParticipant").Where("tournament_id = ?", tID).Find(&rawMatches)
	slices.SortFunc(rawMatches, func(a model.Match, b model.Match) int { return a.Stage - b.Stage })

	if len(rawMatches) < 1 {
		return [][]model.Match{}
	}

	matches := make([][]model.Match, rawMatches[len(rawMatches)-1].Stage)
	for _, match := range rawMatches {
		matches[match.Stage-1] = append(matches[match.Stage-1], match)
	}
	return matches
}

func (a *App) CreateStage(tID uint) {
	oldMatches := a.GetMatches(tID)

	if len(oldMatches) < 1 {
		return
	}

	participants := make([]model.Participant, 0, len(oldMatches[len(oldMatches)-1]))

	for _, m := range oldMatches[len(oldMatches)-1] {
		participants = append(participants, m.WinnerParticipant)
	}

	if len(participants) == 0 {
		return
	}

	stage := oldMatches[len(oldMatches)-1][len(oldMatches[len(oldMatches)-1])-1].Stage + 1

	matches := make([]model.Match, 0, len(participants)/2)
	for i := range len(participants) / 2 {
		matches = append(matches, model.Match{
			TournamentID:   tID,
			Order:          i,
			Stage:          stage,
			Participant1ID: participants[i].ID,
			Participant2ID: participants[i+len(participants)/2].ID,
		})
	}
	if len(participants)%2 != 0 {
		matches = append(matches, model.Match{
			TournamentID:        tID,
			Order:               len(participants)/2 + 1,
			Stage:               stage,
			Participant1ID:      participants[len(participants)-1].ID,
			Participant2ID:      participants[len(participants)-1].ID,
			WinnerParticipantID: participants[len(participants)-1].ID,
		})
	}
	a.db.Save(matches)
}

func (a *App) SaveMatch(m *model.Match) {
	a.db.Save(m)
}