package chat

import (
	"fmt"
	"strings"

	"eq2emu/internal/common"
	"eq2emu/internal/database"
)

// MasterList manages a collection of channels using the generic MasterList base
type MasterList struct {
	*common.MasterList[int32, *Channel]
}

// NewMasterList creates a new channel master list
func NewMasterList() *MasterList {
	return &MasterList{
		MasterList: common.NewMasterList[int32, *Channel](),
	}
}

// AddChannel adds a channel to the master list
func (ml *MasterList) AddChannel(channel *Channel) bool {
	return ml.Add(channel)
}

// GetChannel retrieves a channel by ID
func (ml *MasterList) GetChannel(id int32) *Channel {
	return ml.Get(id)
}

// GetChannelSafe retrieves a channel by ID with existence check
func (ml *MasterList) GetChannelSafe(id int32) (*Channel, bool) {
	return ml.GetSafe(id)
}

// HasChannel checks if a channel exists by ID
func (ml *MasterList) HasChannel(id int32) bool {
	return ml.Exists(id)
}

// RemoveChannel removes a channel by ID
func (ml *MasterList) RemoveChannel(id int32) bool {
	return ml.Remove(id)
}

// GetAllChannels returns all channels as a map
func (ml *MasterList) GetAllChannels() map[int32]*Channel {
	return ml.GetAll()
}

// GetAllChannelsList returns all channels as a slice
func (ml *MasterList) GetAllChannelsList() []*Channel {
	return ml.GetAllSlice()
}

// GetChannelCount returns the number of channels
func (ml *MasterList) GetChannelCount() int {
	return ml.Size()
}

// ClearChannels removes all channels from the list
func (ml *MasterList) ClearChannels() {
	ml.Clear()
}

// FindChannelsByName finds channels containing the given name substring
func (ml *MasterList) FindChannelsByName(nameSubstring string) []*Channel {
	return ml.Filter(func(channel *Channel) bool {
		return contains(channel.GetName(), nameSubstring)
	})
}

// FindChannelsByType finds channels of a specific type
func (ml *MasterList) FindChannelsByType(channelType int) []*Channel {
	return ml.Filter(func(channel *Channel) bool {
		return channel.GetType() == channelType
	})
}

// GetWorldChannels returns all world channels
func (ml *MasterList) GetWorldChannels() []*Channel {
	return ml.FindChannelsByType(ChannelTypeWorld)
}

// GetCustomChannels returns all custom channels
func (ml *MasterList) GetCustomChannels() []*Channel {
	return ml.FindChannelsByType(ChannelTypeCustom)
}

// GetActiveChannels returns channels that have members
func (ml *MasterList) GetActiveChannels() []*Channel {
	return ml.Filter(func(channel *Channel) bool {
		return !channel.IsEmpty()
	})
}

// GetEmptyChannels returns channels that have no members
func (ml *MasterList) GetEmptyChannels() []*Channel {
	return ml.Filter(func(channel *Channel) bool {
		return channel.IsEmpty()
	})
}

// GetChannelByName retrieves a channel by name (case-insensitive)
func (ml *MasterList) GetChannelByName(name string) *Channel {
	name = strings.ToLower(name)
	var foundChannel *Channel
	ml.ForEach(func(id int32, channel *Channel) {
		if strings.ToLower(channel.GetName()) == name {
			foundChannel = channel
		}
	})
	return foundChannel
}

// HasChannelByName checks if a channel exists by name (case-insensitive)
func (ml *MasterList) HasChannelByName(name string) bool {
	return ml.GetChannelByName(name) != nil
}

// GetCompatibleChannels returns channels compatible with player restrictions
func (ml *MasterList) GetCompatibleChannels(level, race, class int32) []*Channel {
	return ml.Filter(func(channel *Channel) bool {
		return channel.CanJoinChannelByLevel(level) &&
			channel.CanJoinChannelByRace(race) &&
			channel.CanJoinChannelByClass(class)
	})
}

// ValidateChannels checks all channels for consistency
func (ml *MasterList) ValidateChannels() []string {
	var issues []string

	ml.ForEach(func(id int32, channel *Channel) {
		if channel == nil {
			issues = append(issues, fmt.Sprintf("Channel ID %d is nil", id))
			return
		}

		if channel.GetID() != id {
			issues = append(issues, fmt.Sprintf("Channel ID mismatch: map key %d != channel ID %d", id, channel.GetID()))
		}

		if len(channel.GetName()) == 0 {
			issues = append(issues, fmt.Sprintf("Channel ID %d has empty name", id))
		}

		if channel.GetType() < ChannelTypeNone || channel.GetType() > ChannelTypeCustom {
			issues = append(issues, fmt.Sprintf("Channel ID %d has invalid type: %d", id, channel.GetType()))
		}

		if len(channel.GetName()) > MaxChannelNameLength {
			issues = append(issues, fmt.Sprintf("Channel ID %d name too long: %d > %d", id, len(channel.GetName()), MaxChannelNameLength))
		}

		if len(channel.Password) > MaxChannelPasswordLength {
			issues = append(issues, fmt.Sprintf("Channel ID %d password too long: %d > %d", id, len(channel.Password), MaxChannelPasswordLength))
		}
	})

	return issues
}

// IsValid returns true if all channels are valid
func (ml *MasterList) IsValid() bool {
	issues := ml.ValidateChannels()
	return len(issues) == 0
}

// GetStatistics returns statistics about the channel collection
func (ml *MasterList) GetStatistics() map[string]any {
	stats := make(map[string]any)
	stats["total_channels"] = ml.Size()

	if ml.IsEmpty() {
		return stats
	}

	// Count by channel type
	typeCounts := make(map[int]int)
	var totalMembers int
	var activeChannels int
	var minID, maxID int32
	first := true

	ml.ForEach(func(id int32, channel *Channel) {
		typeCounts[channel.GetType()]++
		totalMembers += channel.GetNumClients()

		if !channel.IsEmpty() {
			activeChannels++
		}

		if first {
			minID = id
			maxID = id
			first = false
		} else {
			if id < minID {
				minID = id
			}
			if id > maxID {
				maxID = id
			}
		}
	})

	stats["channels_by_type"] = typeCounts
	stats["world_channels"] = typeCounts[ChannelTypeWorld]
	stats["custom_channels"] = typeCounts[ChannelTypeCustom]
	stats["total_members"] = totalMembers
	stats["active_channels"] = activeChannels
	stats["min_id"] = minID
	stats["max_id"] = maxID
	stats["id_range"] = maxID - minID

	return stats
}

// LoadAllChannels loads all channels from the database into the master list
func (ml *MasterList) LoadAllChannels(db *database.Database) error {
	if db == nil {
		return fmt.Errorf("database connection is nil")
	}

	// Clear existing channels
	ml.Clear()

	query := `SELECT id, name, password, type, level_restriction, race_restriction, class_restriction, discord_enabled, created_at, updated_at FROM channels ORDER BY id`
	rows, err := db.Query(query)
	if err != nil {
		return fmt.Errorf("failed to query channels: %w", err)
	}
	defer rows.Close()

	count := 0
	for rows.Next() {
		channel := &Channel{
			db:      db,
			isNew:   false,
			members: make([]int32, 0),
		}

		err := rows.Scan(&channel.ID, &channel.Name, &channel.Password, &channel.ChannelType,
			&channel.LevelRestriction, &channel.RaceRestriction, &channel.ClassRestriction,
			&channel.DiscordEnabled, &channel.Created, &channel.Updated)
		if err != nil {
			return fmt.Errorf("failed to scan channel: %w", err)
		}

		if !ml.AddChannel(channel) {
			return fmt.Errorf("failed to add channel %d to master list", channel.ID)
		}

		count++
	}

	if err := rows.Err(); err != nil {
		return fmt.Errorf("error iterating channel rows: %w", err)
	}

	return nil
}

// LoadAllChannelsFromDatabase is a convenience function that creates a master list and loads all channels
func LoadAllChannelsFromDatabase(db *database.Database) (*MasterList, error) {
	masterList := NewMasterList()
	err := masterList.LoadAllChannels(db)
	if err != nil {
		return nil, err
	}
	return masterList, nil
}

// contains checks if a string contains a substring (case-sensitive)
func contains(str, substr string) bool {
	if len(substr) == 0 {
		return true
	}
	if len(str) < len(substr) {
		return false
	}

	for i := 0; i <= len(str)-len(substr); i++ {
		if str[i:i+len(substr)] == substr {
			return true
		}
	}

	return false
}