package services

import (
	"context"
	"errors"
	"git.aiterp.net/rpdata/api/internal/auth"
	"git.aiterp.net/rpdata/api/models"
	"git.aiterp.net/rpdata/api/models/changekeys"
	"git.aiterp.net/rpdata/api/repositories"
	"git.aiterp.net/rpdata/api/services/loaders"
	"sort"
	"strings"
)

type CharacterService struct {
	characters    repositories.CharacterRepository
	loader        *loaders.CharacterLoader
	changeService *ChangeService
}

// Find uses the loader to find the character by the ID.
func (s *CharacterService) Find(ctx context.Context, id string) (*models.Character, error) {
	return s.loader.Load(id)
}

// Find uses the loader to find the character by the ID.
func (s *CharacterService) FindNick(ctx context.Context, nick string) (*models.Character, error) {
	return s.characters.FindNick(ctx, nick)
}

// List lists the characters. If the only filter active is `IDs`, the loader is used to batch together requests.
func (s *CharacterService) List(ctx context.Context, filter models.CharacterFilter) ([]*models.Character, error) {
	if len(filter.IDs) > 0 && len(filter.Names) == 0 && len(filter.Nicks) == 0 && filter.Author == nil && filter.Search == nil {
		characters, errs := s.loader.LoadAll(filter.IDs)
		if len(characters) == 0 && len(errs) > 0 {
			if errs[0] == repositories.ErrNotFound {
				return []*models.Character{}, nil
			} else {
				return nil, errs[0]
			}
		}

		if err := ctx.Err(); err != nil {
			return nil, err
		}

		var badIndices []int
		for i, character := range characters {
			if character == nil {
				badIndices = append(badIndices, i-len(badIndices))
			}
		}
		for _, index := range badIndices {
			characters = append(characters[:index], characters[index+1:]...)
		}

		sort.Slice(characters, func(i, j int) bool {
			return strings.Compare(characters[i].ID, characters[j].ID) < 0
		})

		return characters, nil
	}

	return s.characters.List(ctx, filter)
}

func (s *CharacterService) Create(ctx context.Context, nick, name, shortName, author, description string) (*models.Character, error) {
	token := auth.TokenFromContext(ctx)
	if token == nil {
		return nil, auth.ErrUnauthenticated
	}

	if name == "" {
		return nil, errors.New("Name cannot be empty")
	}

	if author == "" {
		author = token.UserID
	}

	if shortName == "" {
		split := strings.SplitN(name, " ", 2)
		shortName = split[0]
	}

	character := &models.Character{
		Name:        name,
		ShortName:   shortName,
		Author:      author,
		Nicks:       []string{nick},
		Description: description,
	}

	err := auth.CheckPermission(ctx, "add", character)
	if err != nil {
		return nil, err
	}

	character, err = s.characters.Insert(ctx, *character)
	if err != nil {
		return nil, err
	}

	s.changeService.Submit(ctx, "Character", "add", true, changekeys.Listed(character), character)

	return character, nil
}

func (s *CharacterService) Update(ctx context.Context, id string, name, shortName, description *string) (*models.Character, error) {
	character, err := s.characters.Find(ctx, id)
	if err != nil {
		return nil, err
	}

	err = auth.CheckPermission(ctx, "edit", character)
	if err != nil {
		return nil, err
	}

	character, err = s.characters.Update(ctx, *character, models.CharacterUpdate{
		Name:        name,
		ShortName:   shortName,
		Description: description,
	})
	if err != nil {
		return nil, err
	}

	s.loader.Clear(character.ID)
	s.loader.Prime(character.ID, character)

	s.changeService.Submit(ctx, "Character", "edit", true, changekeys.Listed(character), character)

	return character, nil
}

func (s *CharacterService) AddNick(ctx context.Context, id string, nick string) (*models.Character, error) {
	character, err := s.characters.Find(ctx, id)
	if err != nil {
		return nil, err
	}

	err = auth.CheckPermission(ctx, "edit", character)
	if err != nil {
		return nil, err
	}

	character, err = s.characters.AddNick(ctx, *character, nick)
	if err != nil {
		return nil, err
	}

	s.changeService.Submit(ctx, "Character", "edit", true, changekeys.Listed(character), character)

	return character, nil
}

func (s *CharacterService) RemoveNick(ctx context.Context, id string, nick string) (*models.Character, error) {
	character, err := s.characters.Find(ctx, id)
	if err != nil {
		return nil, err
	}

	err = auth.CheckPermission(ctx, "edit", character)
	if err != nil {
		return nil, err
	}

	character, err = s.characters.RemoveNick(ctx, *character, nick)
	if err != nil {
		return nil, err
	}

	s.changeService.Submit(ctx, "Character", "edit", true, changekeys.Listed(character), character)

	return character, nil
}

func (s *CharacterService) Delete(ctx context.Context, id string) (*models.Character, error) {
	character, err := s.characters.Find(ctx, id)
	if err != nil {
		return nil, err
	}

	err = auth.CheckPermission(ctx, "edit", character)
	if err != nil {
		return nil, err
	}

	err = s.characters.Delete(ctx, *character)
	if err != nil {
		return nil, err
	}

	s.changeService.Submit(ctx, "Character", "remove", true, changekeys.Listed(character), character)

	return character, nil
}