package channel

import (
	"errors"

	"github.com/google/uuid"
	"github.com/justamessenger/server/internal/database"
	"github.com/justamessenger/server/internal/models"
)

type Manager struct {
	db *database.DB
}

func NewManager(db *database.DB) *Manager {
	return &Manager{db: db}
}

func (m *Manager) Create(guildID, categoryID, name, channelType, topic string, position int) (*models.Channel, error) {
	id := uuid.New().String()
	_, err := m.db.Exec(
		`INSERT INTO channels (id, guild_id, category_id, name, type, topic, position)
		 VALUES (?, ?, ?, ?, ?, ?, ?)`,
		id, guildID, categoryID, name, channelType, topic, position,
	)
	if err != nil {
		return nil, err
	}
	return m.Get(id)
}

func (m *Manager) Get(id string) (*models.Channel, error) {
	row := m.db.QueryRow(
		`SELECT id, guild_id, category_id, name, type, topic, position, created_at
		 FROM channels WHERE id = ?`, id,
	)
	c := &models.Channel{}
	err := row.Scan(&c.ID, &c.GuildID, &c.Category, &c.Name, &c.Type, &c.Topic, &c.Position, &c.CreatedAt)
	if err != nil {
		return nil, err
	}
	return c, nil
}

func (m *Manager) ListByGuild(guildID string) ([]*models.Channel, error) {
	rows, err := m.db.Query(
		`SELECT id, guild_id, category_id, name, type, topic, position, created_at
		 FROM channels WHERE guild_id = ? ORDER BY position`, guildID,
	)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var channels []*models.Channel
	for rows.Next() {
		c := &models.Channel{}
		if err := rows.Scan(&c.ID, &c.GuildID, &c.Category, &c.Name, &c.Type, &c.Topic, &c.Position, &c.CreatedAt); err != nil {
			return nil, err
		}
		channels = append(channels, c)
	}
	return channels, nil
}

func (m *Manager) Update(id, name, topic string, position int) error {
	result, err := m.db.Exec(
		`UPDATE channels SET name = ?, topic = ?, position = ? WHERE id = ?`,
		name, topic, position, id,
	)
	if err != nil {
		return err
	}
	affected, _ := result.RowsAffected()
	if affected == 0 {
		return errors.New("channel not found")
	}
	return nil
}

func (m *Manager) Delete(id string) error {
	result, err := m.db.Exec(`DELETE FROM channels WHERE id = ?`, id)
	if err != nil {
		return err
	}
	affected, _ := result.RowsAffected()
	if affected == 0 {
		return errors.New("channel not found")
	}
	return nil
}

func (m *Manager) CreateCategory(guildID, name string, position int) (string, error) {
	id := uuid.New().String()
	_, err := m.db.Exec(
		`INSERT INTO categories (id, guild_id, name, position) VALUES (?, ?, ?, ?)`,
		id, guildID, name, position,
	)
	if err != nil {
		return "", err
	}
	return id, nil
}

func (m *Manager) ListCategories(guildID string) ([]*struct {
	ID       string
	Name     string
	Position int
}, error) {
	rows, err := m.db.Query(
		`SELECT id, name, position FROM categories WHERE guild_id = ? ORDER BY position`, guildID,
	)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var cats []*struct {
		ID       string
		Name     string
		Position int
	}
	for rows.Next() {
		var c struct {
			ID       string
			Name     string
			Position int
		}
		if err := rows.Scan(&c.ID, &c.Name, &c.Position); err != nil {
			return nil, err
		}
		cats = append(cats, &c)
	}
	return cats, nil
}