package dao

import (
	"opencatd-open/internal/store"

	"gorm.io/gorm"
)

type ChannelDAO struct {
	db *gorm.DB
}

func NewChannelDAO(db *gorm.DB) *ChannelDAO {
	return &ChannelDAO{db: db}
}

func (d *ChannelDAO) Create(channel *store.Channel) error {
	return d.db.Create(channel).Error
}

func (d *ChannelDAO) GetByID(id uint64) (*store.Channel, error) {
	var channel store.Channel
	err := d.db.First(&channel, id).Error
	if err != nil {
		return nil, err
	}
	return &channel, nil
}

func (d *ChannelDAO) GetByName(name string) (*store.Channel, error) {
	var channel store.Channel
	err := d.db.Where("name = ?", name).First(&channel).Error
	if err != nil {
		return nil, err
	}
	return &channel, nil
}

func (d *ChannelDAO) List(limit, offset int) ([]*store.Channel, int64, error) {
	var channels []*store.Channel
	var total int64
	d.db.Model(&store.Channel{}).Count(&total)
	err := d.db.Limit(limit).Offset(offset).Order("priority DESC, weight DESC").Find(&channels).Error
	return channels, total, err
}

func (d *ChannelDAO) ListEnabled() ([]*store.Channel, error) {
	var channels []*store.Channel
	err := d.db.Where("enabled = ?", true).Order("priority DESC, weight DESC").Find(&channels).Error
	return channels, err
}

func (d *ChannelDAO) Update(channel *store.Channel) error {
	return d.db.Save(channel).Error
}

func (d *ChannelDAO) Delete(id uint64) error {
	return d.db.Delete(&store.Channel{}, id).Error
}

// BindModels binds models to a channel (replaces existing bindings)
func (d *ChannelDAO) BindModels(channelID uint64, bindings []store.ChannelModelBinding) error {
	return d.db.Transaction(func(tx *gorm.DB) error {
		// Delete existing bindings
		if err := tx.Where("channel_id = ?", channelID).Delete(&store.ChannelModelBinding{}).Error; err != nil {
			return err
		}
		// Create new bindings
		for i := range bindings {
			bindings[i].ChannelID = channelID
		}
		return tx.Create(&bindings).Error
	})
}

// GetChannelModels returns all models bound to a channel
func (d *ChannelDAO) GetChannelModels(channelID uint64) ([]store.ChannelModelBinding, error) {
	var bindings []store.ChannelModelBinding
	err := d.db.Where("channel_id = ?", channelID).Find(&bindings).Error
	return bindings, err
}

// GetModelChannels returns all channels that support a given model (by model name)
func (d *ChannelDAO) GetModelChannels(modelName string) ([]store.ChannelModelBinding, error) {
	var bindings []store.ChannelModelBinding
	err := d.db.
		Joins("JOIN channels ON channels.id = channel_model_bindings.channel_id").
		Joins("JOIN models ON models.id = channel_model_bindings.model_id").
		Where("models.name = ? AND channels.enabled = ?", modelName, true).
		Find(&bindings).Error
	return bindings, err
}

// GetEnabledChannelsByModel returns enabled channels for a model, ordered by priority/weight
func (d *ChannelDAO) GetEnabledChannelsByModel(modelName string) ([]*store.Channel, error) {
	var channels []*store.Channel
	err := d.db.
		Distinct("channels.*").
		Joins("JOIN channel_model_bindings ON channel_model_bindings.channel_id = channels.id").
		Joins("JOIN models ON models.id = channel_model_bindings.model_id").
		Where("models.name = ? AND channels.enabled = ?", modelName, true).
		Order("channels.priority DESC, channels.weight DESC").
		Find(&channels).Error
	return channels, err
}