using Microsoft.Extensions.Logging;
using MySqlConnector;
using SharpChat.Data;
using SharpChat.Messages;
using System.Data.Common;
using System.Text;
using System.Text.Json;
using ZLogger;

namespace SharpChat.MariaDB;

public class MariaDBMessageStorage(MariaDBStorage storage, ILogger logger) : MessageStorage {
    public async Task LogMessage(Message msg) {
        try {
            using MariaDBConnection conn = await storage.CreateConnection();
            await conn.RunCommand(
                "INSERT IGNORE INTO sqc_events (event_id, event_type, event_channel, event_data"
                + ", event_sender, event_sender_name, event_sender_colour, event_sender_rank, event_sender_nick, event_sender_perms"
                + ", event_created, event_deleted)"
                + " VALUES (@id, @type, @channel, @data"
                + ", @sender, @sender_name, @sender_colour, @sender_rank, @sender_nick, @sender_perms"
                + ", FROM_UNIXTIME(@created), FROM_UNIXTIME(@deleted))",
                new MySqlParameter("id", msg.Id),
                new MySqlParameter("type", msg.Type),
                new MySqlParameter("channel", string.IsNullOrWhiteSpace(msg.ChannelName) ? null : msg.ChannelName),
                new MySqlParameter("data", JsonSerializer.SerializeToUtf8Bytes(msg.Data)),
                new MySqlParameter("sender", long.TryParse(msg.SenderId, out long senderId64) && senderId64 > 0 ? senderId64 : null),
                new MySqlParameter("sender_name", msg.SenderName),
                new MySqlParameter("sender_colour", msg.SenderColour.ToMisuzu()),
                new MySqlParameter("sender_rank", msg.SenderRank),
                new MySqlParameter("sender_nick", string.IsNullOrWhiteSpace(msg.SenderNickName) ? null : msg.SenderNickName),
                new MySqlParameter("sender_perms", MariaDBUserPermissionsConverter.To(msg.SenderPermissions)),
                new MySqlParameter("created", msg.Created.ToUnixTimeSeconds()),
                new MySqlParameter("deleted", msg.Deleted?.ToUnixTimeSeconds())
            );
        } catch(MySqlException ex) {
            logger.ZLogError($"Error in LogMessage(Message): {ex}");
        }
    }

    public async Task LogMessage(
        long id,
        string type,
        string channelName,
        string senderId,
        string senderName,
        ColourInheritable senderColour,
        int senderRank,
        string senderNick,
        UserPermissions senderPerms,
        object? data = null
    ) {
        try {
            using MariaDBConnection conn = await storage.CreateConnection();
            await conn.RunCommand(
                "INSERT INTO sqc_events (event_id, event_created, event_type, event_channel, event_data"
                + ", event_sender, event_sender_name, event_sender_colour, event_sender_rank, event_sender_nick, event_sender_perms)"
                + " VALUES (@id, NOW(), @type, @channel, @data"
                + ", @sender, @sender_name, @sender_colour, @sender_rank, @sender_nick, @sender_perms)",
                new MySqlParameter("id", id),
                new MySqlParameter("type", type),
                new MySqlParameter("channel", string.IsNullOrWhiteSpace(channelName) ? null : channelName),
                new MySqlParameter("data", data == null ? "{}" : JsonSerializer.SerializeToUtf8Bytes(data)),
                new MySqlParameter("sender", long.TryParse(senderId, out long senderId64) && senderId64 > 0 ? senderId64 : null),
                new MySqlParameter("sender_name", senderName),
                new MySqlParameter("sender_colour", senderColour.ToMisuzu()),
                new MySqlParameter("sender_rank", senderRank),
                new MySqlParameter("sender_nick", string.IsNullOrWhiteSpace(senderNick) ? null : senderNick),
                new MySqlParameter("sender_perms", MariaDBUserPermissionsConverter.To(senderPerms))
            );
        } catch(MySqlException ex) {
            logger.ZLogError($"Error in LogMessage(long, ...): {ex}");
        }
    }

    public async Task DeleteMessage(Message msg) {
        try {
            using MariaDBConnection conn = await storage.CreateConnection();
            await conn.RunCommand(
                "UPDATE IGNORE sqc_events SET event_deleted = NOW() WHERE event_id = @id AND event_deleted IS NULL",
                new MySqlParameter("id", msg.Id)
            );
        } catch(MySqlException ex) {
            logger.ZLogError($"Error in DeleteMessage(): {ex}");
        }
    }

    private static Message ReadMessage(DbDataReader reader) {
        using Stream data = reader.GetStream(reader.GetOrdinal("event_data"));
        return new Message(
            reader.GetInt64(reader.GetOrdinal("event_id")),
            reader.GetString(reader.GetOrdinal("event_type")),
            reader.IsDBNull(reader.GetOrdinal("event_sender")) ? null : reader.GetString(reader.GetOrdinal("event_sender")),
            reader.IsDBNull(reader.GetOrdinal("event_sender_name")) ? string.Empty : reader.GetString(reader.GetOrdinal("event_sender_name")),
            ColourInheritable.FromMisuzu(reader.GetInt32(reader.GetOrdinal("event_sender_colour"))),
            reader.GetInt32(reader.GetOrdinal("event_sender_rank")),
            MariaDBUserPermissionsConverter.From((MariaDBUserPermissions)reader.GetInt32(reader.GetOrdinal("event_sender_perms"))),
            reader.IsDBNull(reader.GetOrdinal("event_sender_nick")) ? string.Empty : reader.GetString(reader.GetOrdinal("event_sender_nick")),
            DateTimeOffset.FromUnixTimeSeconds(reader.GetInt32(reader.GetOrdinal("event_created"))),
            reader.IsDBNull(reader.GetOrdinal("event_deleted")) ? null : DateTimeOffset.FromUnixTimeSeconds(reader.GetInt32(reader.GetOrdinal("event_deleted"))),
            reader.IsDBNull(reader.GetOrdinal("event_channel")) ? null : reader.GetString(reader.GetOrdinal("event_channel")),
            JsonDocument.Parse(data)
        );
    }

    public async Task<Message?> GetMessage(long id) {
        try {
            using MariaDBConnection conn = await storage.CreateConnection();
            using MySqlDataReader? reader = await conn.RunQuery(
                "SELECT event_id, event_type, event_data, event_channel"
                + ", event_sender, event_sender_name, event_sender_colour, event_sender_rank, event_sender_nick, event_sender_perms"
                + ", UNIX_TIMESTAMP(event_created) AS event_created"
                + ", UNIX_TIMESTAMP(event_deleted) AS event_deleted"
                + " FROM sqc_events"
                + " WHERE event_id = @id",
                new MySqlParameter("id", id)
            );

            if(reader is null)
                return null;

            while(reader.Read()) {
                Message evt = ReadMessage(reader);
                if(evt != null)
                    return evt;
            }
        } catch(MySqlException ex) {
            logger.ZLogError($"Error in GetMessage(): {ex}");
        }

        return null;
    }

    public async Task<long> CountMessages(
        string? channelName = null,
        bool includeDeleted = false
    ) {
        List<MySqlParameter> parameters = [];
        bool firstParam = true;
        StringBuilder qb = new();
        qb.Append("SELECT COUNT(*) FROM sqc_events");

        if(!includeDeleted) {
            firstParam = false;
            qb.Append(" WHERE event_deleted IS NULL");
        }

        if(!string.IsNullOrEmpty(channelName)) {
            qb.AppendFormat(" {0} (event_channel = @channel OR event_channel IS NULL)", firstParam ? "WHERE" : "AND");
            parameters.Add(new MySqlParameter("channel", channelName));
        }

        try {
            using MariaDBConnection conn = await storage.CreateConnection();
            return await conn.RunQueryValue<long>(qb.ToString(), [.. parameters]);
        } catch(MySqlException ex) {
            logger.ZLogError($"Error in CountMessages({channelName}, {includeDeleted}): {ex}");
            return 0;
        }
    }

    public async Task<IEnumerable<Message>> GetMessages(
        string? channelName = null,
        int? take = 20,
        long? beforeId = null,
        bool includeDeleted = false
    ) {
        List<MySqlParameter> parameters = [];
        bool firstParam = true;
        StringBuilder qb = new();
        qb.Append("SELECT event_id, event_type, event_data, event_channel");
        qb.Append(", event_sender, event_sender_name, event_sender_colour, event_sender_rank, event_sender_nick, event_sender_perms");
        qb.Append(", UNIX_TIMESTAMP(event_created) AS event_created");
        qb.Append(", UNIX_TIMESTAMP(event_deleted) AS event_deleted");
        qb.Append(" FROM sqc_events");

        if(!includeDeleted) {
            firstParam = false;
            qb.Append(" WHERE event_deleted IS NULL");
        }

        if(!string.IsNullOrEmpty(channelName)) {
            qb.AppendFormat(" {0} (event_channel = @channel OR event_channel IS NULL)", firstParam ? "WHERE" : "AND");
            parameters.Add(new MySqlParameter("channel", channelName));
            firstParam = false;
        }

        if(beforeId.HasValue) {
            qb.AppendFormat(" {0} event_id < @before", firstParam ? "WHERE" : "AND");
            parameters.Add(new MySqlParameter("before", beforeId.Value));
        }

        qb.Append(" ORDER BY event_id DESC");

        if(take.HasValue) {
            qb.Append(" LIMIT @take");
            parameters.Add(new MySqlParameter("take", take.Value));
        }

        string query = string.Format("SELECT * FROM ({0}) AS _ ORDER BY event_id ASC", qb);

        try {
            MariaDBConnection conn = await storage.CreateConnection();
            DbDataReader? reader = await conn.RunQuery(query, [.. parameters]);

            if(reader is null) {
                conn.Dispose();
                return [];
            }

            return new DbObjectEnumerable<Message>(reader, ReadMessage, () => conn.Dispose());
        } catch(MySqlException ex) {
            logger.ZLogError($"Error in GetMessages({channelName}, {take}, {beforeId}, {includeDeleted}): {ex}");
            return [];
        }
    }
}