using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.Json;
using System.Threading.Tasks;
using Dapper;
using Gott.Models;

namespace Gott.Services;

public partial class DatabaseService
{
    // ── Sessions ──

    public async Task<SessionRecord> CreateSession(string userId, string name = null, string description = null, string image = null, string imageSmall = null, string agentId = null, string workspace = null, string context = null, string customCommands = null, double avatarScale = 1.0, double avatarOffsetX = 0, double avatarOffsetY = 0, string reviewAgentId = null, int maxReviewIterations = 3, string finalizerAgentId = null, string preparerAgentId = null, string multiModelMode = null, string panelAgentIds = null, int moaLayers = 2)
    {
        using var conn = CreateConnection();
        var now = DateTime.UtcNow.ToString("o");
        var session = new SessionRecord
        {
            SessionId = Guid.NewGuid().ToString("N"),
            UserId = userId,
            Name = name,
            Description = description,
            Image = image,
            ImageSmall = imageSmall,
            AgentId = agentId,
            Workspace = workspace,
            Context = context,
            CustomCommands = customCommands,
            AvatarScale = avatarScale,
            AvatarOffsetX = avatarOffsetX,
            AvatarOffsetY = avatarOffsetY,
            ReviewAgentId = reviewAgentId,
            MaxReviewIterations = maxReviewIterations,
            FinalizerAgentId = finalizerAgentId,
            PreparerAgentId = preparerAgentId,
            MultiModelMode = multiModelMode,
            PanelAgentIds = panelAgentIds,
            MoaLayers = moaLayers,
            CreatedAt = now,
            UpdatedAt = now
        };
        await conn.ExecuteAsync(@"
            INSERT INTO sessions (session_id, user_id, name, description, image, image_small, agent_id, workspace, context, custom_commands, avatar_scale, avatar_offset_x, avatar_offset_y, review_agent_id, max_review_iterations, finalizer_agent_id, preparer_agent_id, multi_model_mode, panel_agent_ids, moa_layers, created_at, updated_at)
            VALUES (@SessionId, @UserId, @Name, @Description, @Image, @ImageSmall, @AgentId, @Workspace, @Context, @CustomCommands, @AvatarScale, @AvatarOffsetX, @AvatarOffsetY, @ReviewAgentId, @MaxReviewIterations, @FinalizerAgentId, @PreparerAgentId, @MultiModelMode, @PanelAgentIds, @MoaLayers, @CreatedAt, @UpdatedAt)
        ", session);
        return session;
    }

    public async Task<SessionRecord> GetSessionByName(string name)
    {
        using var conn = CreateConnection();
        var sessions = await conn.QueryAsync<SessionRecord>(
            "SELECT * FROM sessions WHERE is_deleted = 0 AND LOWER(name) = LOWER(@name) ORDER BY updated_at DESC LIMIT 1",
            new { name });
        return sessions.FirstOrDefault();
    }

    public async Task<List<SessionWithStats>> GetSessionsWithStats(string userId)
    {
        using var conn = CreateConnection();
        var sessions = await conn.QueryAsync<SessionRecord>(@"
            SELECT s.* FROM sessions s
            LEFT JOIN (
                SELECT c.session_id, MAX(m.created_at) AS last_message_at
                FROM chains c
                JOIN messages m ON m.chain_id = c.chain_id
                WHERE m.type = 'text'
                GROUP BY c.session_id
            ) lm ON lm.session_id = s.session_id
            WHERE s.user_id = @userId AND s.is_deleted = 0
            ORDER BY COALESCE(lm.last_message_at, s.updated_at) DESC", new { userId });

        var results = new List<SessionWithStats>();
        foreach (var s in sessions)
        {
            var activeCount = await conn.ExecuteScalarAsync<int>(@"
                SELECT COUNT(*) FROM messages m
                JOIN chains c ON m.chain_id = c.chain_id
                WHERE c.session_id = @sessionId AND c.archive_id IS NULL AND m.type = 'text'",
                new { sessionId = s.SessionId });

            var totalCount = await conn.ExecuteScalarAsync<int>(@"
                SELECT COUNT(*) FROM messages m
                JOIN chains c ON m.chain_id = c.chain_id
                WHERE c.session_id = @sessionId AND m.type = 'text'",
                new { sessionId = s.SessionId });

            results.Add(new SessionWithStats
            {
                Session = s,
                MessageCount = activeCount,
                ArchiveMessageCount = totalCount - activeCount,
                TotalMessageCount = totalCount,
                TelegramConfigured = !string.IsNullOrEmpty(s.TelegramBotId),
                TelegramLinked = !string.IsNullOrEmpty(s.TelegramChatId)
            });
        }
        return results;
    }

    public async Task<SessionRecord> GetSession(string sessionId)
    {
        using var conn = CreateConnection();
        return await conn.QuerySingleOrDefaultAsync<SessionRecord>(
            "SELECT * FROM sessions WHERE session_id = @sessionId AND is_deleted = 0", new { sessionId });
    }

    public async Task UpdateSessionTimestamp(string sessionId)
    {
        using var conn = CreateConnection();
        await conn.ExecuteAsync(
            "UPDATE sessions SET updated_at = @now WHERE session_id = @sessionId",
            new { sessionId, now = DateTime.UtcNow.ToString("o") });
    }

    public async Task UpdateSession(string sessionId, System.Text.Json.JsonElement body, ImageService imageService = null, bool allowUserReassign = false)
    {
        using var conn = CreateConnection();
        var sets = new List<string> { "updated_at = @now" };
        var p = new Dapper.DynamicParameters();
        p.Add("sessionId", sessionId);
        p.Add("now", DateTime.UtcNow.ToString("o"));

        // Session einem anderen Benutzer zuweisen – nur wenn explizit erlaubt (Admin).
        // Leerer/null userId wird ignoriert (eine Session muss immer einen Besitzer haben).
        if (allowUserReassign && body.TryGetProperty("userId", out var uid)
            && uid.ValueKind == System.Text.Json.JsonValueKind.String
            && !string.IsNullOrWhiteSpace(uid.GetString()))
        {
            sets.Add("user_id = @newUserId");
            p.Add("newUserId", uid.GetString());
        }

        if (body.TryGetProperty("name", out var n)) { sets.Add("name = @name"); p.Add("name", n.GetString()); }
        if (body.TryGetProperty("description", out var d)) { sets.Add("description = @desc"); p.Add("desc", d.GetString()); }
        if (body.TryGetProperty("image", out var img))
        {
            var imageData = img.GetString();
            if (imageService != null)
            {
                sets.Add("image_small = @imageSmall");
                p.Add("imageSmall", imageService.ResizeDataUrlSmall(imageData));
                imageData = imageService.ResizeDataUrl(imageData);
            }
            sets.Add("image = @image");
            p.Add("image", imageData);
        }
        if (body.TryGetProperty("agentId", out var a)) { sets.Add("agent_id = @agentId2"); p.Add("agentId2", a.GetString()); }
        if (body.TryGetProperty("workspace", out var w)) { sets.Add("workspace = @workspace"); p.Add("workspace", w.GetString()); }
        if (body.TryGetProperty("context", out var ctx)) { sets.Add("context = @context"); p.Add("context", ctx.GetString()); }
        if (body.TryGetProperty("customCommands", out var cc)) { sets.Add("custom_commands = @customCommands"); p.Add("customCommands", cc.ValueKind == System.Text.Json.JsonValueKind.Null ? null : cc.GetRawText()); }
        if (body.TryGetProperty("avatarScale", out var asc)) { sets.Add("avatar_scale = @avatarScale"); p.Add("avatarScale", asc.GetDouble()); }
        if (body.TryGetProperty("avatarOffsetX", out var aox)) { sets.Add("avatar_offset_x = @avatarOffsetX"); p.Add("avatarOffsetX", aox.GetDouble()); }
        if (body.TryGetProperty("avatarOffsetY", out var aoy)) { sets.Add("avatar_offset_y = @avatarOffsetY"); p.Add("avatarOffsetY", aoy.GetDouble()); }
        if (body.TryGetProperty("reviewAgentId", out var ra)) { sets.Add("review_agent_id = @reviewAgentId"); p.Add("reviewAgentId", ra.ValueKind == System.Text.Json.JsonValueKind.Null ? null : ra.GetString()); }
        if (body.TryGetProperty("maxReviewIterations", out var mri)) { sets.Add("max_review_iterations = @maxReviewIterations"); p.Add("maxReviewIterations", mri.GetInt32()); }
        if (body.TryGetProperty("finalizerAgentId", out var fa)) { sets.Add("finalizer_agent_id = @finalizerAgentId"); p.Add("finalizerAgentId", fa.ValueKind == System.Text.Json.JsonValueKind.Null ? null : fa.GetString()); }
        if (body.TryGetProperty("preparerAgentId", out var pa)) { sets.Add("preparer_agent_id = @preparerAgentId"); p.Add("preparerAgentId", pa.ValueKind == System.Text.Json.JsonValueKind.Null ? null : pa.GetString()); }
        if (body.TryGetProperty("multiModelMode", out var mmm)) { sets.Add("multi_model_mode = @multiModelMode"); p.Add("multiModelMode", mmm.ValueKind == System.Text.Json.JsonValueKind.Null ? null : mmm.GetString()); }
        if (body.TryGetProperty("panelAgentIds", out var pai)) { sets.Add("panel_agent_ids = @panelAgentIds"); p.Add("panelAgentIds", pai.ValueKind == System.Text.Json.JsonValueKind.Null ? null : pai.GetString()); }
        if (body.TryGetProperty("moaLayers", out var mol) && mol.ValueKind == System.Text.Json.JsonValueKind.Number) { sets.Add("moa_layers = @moaLayers"); p.Add("moaLayers", mol.GetInt32()); }
        if (body.TryGetProperty("unityMcpUrl", out var umu)) { sets.Add("unity_mcp_url = @unityMcpUrl"); p.Add("unityMcpUrl", umu.ValueKind == System.Text.Json.JsonValueKind.Null ? null : umu.GetString()); }
        if (body.TryGetProperty("unityMcpToken", out var umt)) { sets.Add("unity_mcp_token = @unityMcpToken"); p.Add("unityMcpToken", umt.ValueKind == System.Text.Json.JsonValueKind.Null ? null : umt.GetString()); }
        if (body.TryGetProperty("mcpServers", out var mcps)) { sets.Add("mcp_servers = @mcpServers"); p.Add("mcpServers", mcps.ValueKind == System.Text.Json.JsonValueKind.Null ? null : mcps.GetRawText()); }

        await conn.ExecuteAsync($"UPDATE sessions SET {string.Join(", ", sets)} WHERE session_id = @sessionId", p);
    }

    public async Task DeleteSession(string sessionId, string userId)
    {
        using var conn = CreateConnection();
        await conn.ExecuteAsync(
            "UPDATE sessions SET is_deleted = 1, updated_at = @now WHERE session_id = @sessionId AND user_id = @userId",
            new { sessionId, userId, now = DateTime.UtcNow.ToString("o") });
    }

    // ── Archives ──

    public async Task<ArchiveRecord> CreateArchive(string sessionId, string name = null)
    {
        using var conn = CreateConnection();

        var chainCount = await conn.ExecuteScalarAsync<int>(
            "SELECT COUNT(*) FROM chains WHERE archive_id IS NULL AND session_id = @sessionId",
            new { sessionId });
        if (chainCount == 0) return null;

        var messageCount = await conn.ExecuteScalarAsync<int>(@"
            SELECT COUNT(*) FROM messages
            WHERE type = 'text' AND chain_id IN (SELECT chain_id FROM chains WHERE archive_id IS NULL AND session_id = @sessionId)",
            new { sessionId });

        var archive = new ArchiveRecord
        {
            ArchiveId = Guid.NewGuid().ToString("N"),
            SessionId = sessionId,
            Name = name,
            ChainCount = chainCount,
            MessageCount = messageCount,
            CreatedAt = DateTime.UtcNow.ToString("o")
        };

        await conn.ExecuteAsync(@"
            INSERT INTO archives (archive_id, session_id, name, chain_count, message_count, created_at)
            VALUES (@ArchiveId, @SessionId, @Name, @ChainCount, @MessageCount, @CreatedAt)
        ", archive);

        await conn.ExecuteAsync(
            "UPDATE chains SET archive_id = @archiveId WHERE archive_id IS NULL AND session_id = @sessionId",
            new { archiveId = archive.ArchiveId, sessionId });

        return archive;
    }

    public async Task<IEnumerable<ArchiveRecord>> GetArchives(string sessionId)
    {
        using var conn = CreateConnection();
        return await conn.QueryAsync<ArchiveRecord>(
            "SELECT * FROM archives WHERE session_id = @sessionId ORDER BY id DESC",
            new { sessionId });
    }

    public async Task<IEnumerable<ChainRecord>> GetArchiveChains(string archiveId)
    {
        using var conn = CreateConnection();
        return await conn.QueryAsync<ChainRecord>(
            "SELECT * FROM chains WHERE archive_id = @archiveId ORDER BY id",
            new { archiveId });
    }

    // ── Chains ──

    public async Task CreateChain(ChainRecord chain)
    {
        using var conn = CreateConnection();
        chain.CreatedAt = DateTime.UtcNow.ToString("o");
        await conn.ExecuteAsync(@"
            INSERT INTO chains (chain_id, session_id, archive_id, agent_id, model, system_prompt, tool_choice, tool_names, input_tokens, output_tokens, iterations, stop_reason, duration_ms, plan_mode, effort, created_at)
            VALUES (@ChainId, @SessionId, @ArchiveId, @AgentId, @Model, @SystemPrompt, @ToolChoice, @ToolNames, @InputTokens, @OutputTokens, @Iterations, @StopReason, @DurationMs, @PlanMode, @Effort, @CreatedAt)
        ", chain);
    }

    public async Task UpdateChain(ChainRecord chain)
    {
        using var conn = CreateConnection();
        await conn.ExecuteAsync(@"
            UPDATE chains SET
                input_tokens = @InputTokens,
                output_tokens = @OutputTokens,
                cache_creation_tokens = @CacheCreationTokens,
                cache_read_tokens = @CacheReadTokens,
                iterations = @Iterations,
                stop_reason = @StopReason,
                stream_error_info = @StreamErrorInfo,
                workflow_info = @WorkflowInfo,
                duration_ms = @DurationMs
            WHERE chain_id = @ChainId
        ", chain);
    }

    public async Task<ChainRecord> GetChain(string chainId)
    {
        using var conn = CreateConnection();
        return await conn.QuerySingleOrDefaultAsync<ChainRecord>(
            "SELECT * FROM chains WHERE chain_id = @chainId", new { chainId }
        );
    }

    public async Task<IEnumerable<ChainRecord>> GetActiveChains(string sessionId)
    {
        using var conn = CreateConnection();
        return await conn.QueryAsync<ChainRecord>(
            "SELECT * FROM chains WHERE session_id = @sessionId AND archive_id IS NULL ORDER BY id DESC",
            new { sessionId });
    }

    // ── Messages ──

    public async Task<long> SaveMessage(MessageRecord record)
    {
        using var conn = CreateConnection();
        record.CreatedAt = DateTime.UtcNow.ToString("o");
        return await conn.ExecuteScalarAsync<long>(@"
            INSERT INTO messages (chain_id, role, type, content, tool_name, tool_call_id, is_error, iteration, attachment_count, tag, thought_signature, created_at)
            VALUES (@ChainId, @Role, @Type, @Content, @ToolName, @ToolCallId, @IsError, @Iteration, @AttachmentCount, @Tag, @ThoughtSignature, @CreatedAt);
            SELECT last_insert_rowid();
        ", record);
    }

    /// <summary>
    /// Speichert Message + Attachments in einer Transaktion (1x fsync statt N+1).
    /// </summary>
    public async Task<long> SaveMessageWithAttachments(MessageRecord record, List<AttachmentRecord> attachments)
    {
        using var conn = CreateConnection();
        using var tx = conn.BeginTransaction();

        record.CreatedAt = DateTime.UtcNow.ToString("o");
        record.AttachmentCount = attachments?.Count ?? 0;
        if (attachments != null && attachments.Count > 0)
        {
            var names = attachments.Select(a => a.FileName ?? "").ToArray();
            record.AttachmentNames = System.Text.Json.JsonSerializer.Serialize(names);
        }
        var messageId = await conn.ExecuteScalarAsync<long>(@"
            INSERT INTO messages (chain_id, role, type, content, tool_name, tool_call_id, is_error, iteration, attachment_count, attachment_names, tag, created_at)
            VALUES (@ChainId, @Role, @Type, @Content, @ToolName, @ToolCallId, @IsError, @Iteration, @AttachmentCount, @AttachmentNames, @Tag, @CreatedAt);
            SELECT last_insert_rowid();
        ", record, tx);

        if (attachments != null)
        {
            var now = DateTime.UtcNow.ToString("o");
            foreach (var att in attachments)
            {
                att.MessageId = messageId;
                att.CreatedAt = now;
                await conn.ExecuteAsync(@"
                    INSERT INTO attachments (message_id, type, media_type, file_name, data, created_at)
                    VALUES (@MessageId, @Type, @MediaType, @FileName, @Data, @CreatedAt)
                ", att, tx);
            }
        }

        tx.Commit();
        return messageId;
    }


    // ── Attachments ──

    public async Task<IEnumerable<AttachmentRecord>> GetAttachments(long messageId)
    {
        using var conn = CreateConnection();
        return await conn.QueryAsync<AttachmentRecord>(
            "SELECT * FROM attachments WHERE message_id = @messageId ORDER BY id",
            new { messageId });
    }

    public async Task<IEnumerable<AttachmentRecord>> GetAttachmentsForMessages(IEnumerable<long> messageIds)
    {
        using var conn = CreateConnection();
        return await conn.QueryAsync<AttachmentRecord>(
            "SELECT * FROM attachments WHERE message_id IN @messageIds ORDER BY id",
            new { messageIds });
    }

    public async Task<IEnumerable<MessageRecord>> GetChainMessages(string chainId, bool includeDeleted = false)
    {
        using var conn = CreateConnection();
        var deletedFilter = includeDeleted ? "" : " AND deleted_on IS NULL";
        return await conn.QueryAsync<MessageRecord>(
            $"SELECT * FROM messages WHERE chain_id = @chainId{deletedFilter} ORDER BY id", new { chainId }
        );
    }

    public async Task<int> GetActiveMessageCount(string sessionId, bool includeDeleted = false)
    {
        using var conn = CreateConnection();
        var deletedFilter = includeDeleted ? "" : "AND m.deleted_on IS NULL";
        return await conn.ExecuteScalarAsync<int>($@"
            SELECT COUNT(*) FROM messages m
            JOIN chains c ON m.chain_id = c.chain_id
            WHERE c.archive_id IS NULL AND c.session_id = @sessionId AND m.type = 'text' {deletedFilter}",
            new { sessionId });
    }

    public async Task<List<MessageRecord>> GetLatestActiveMessages(string sessionId, int limit, bool includeDeleted = false)
    {
        using var conn = CreateConnection();
        var deletedFilter = includeDeleted ? "" : "AND m.deleted_on IS NULL";
        var messages = await conn.QueryAsync<MessageRecord>($@"
            SELECT m.*, (CASE WHEN m.tag = 'openclaw-import' THEN m.id - 10000000000 ELSE m.id END) AS sort_key FROM messages m
            JOIN chains c ON m.chain_id = c.chain_id
            WHERE c.archive_id IS NULL AND c.session_id = @sessionId {deletedFilter}
            ORDER BY sort_key DESC LIMIT @limit",
            new { sessionId, limit });
        return messages.Reverse().ToList();
    }

    public async Task<int> GetActiveMessageCountBeforeSortKey(string sessionId, long beforeSortKey, bool includeDeleted = false)
    {
        using var conn = CreateConnection();
        var deletedFilter = includeDeleted ? "" : "AND m.deleted_on IS NULL";
        return await conn.ExecuteScalarAsync<int>($@"
            SELECT COUNT(*) FROM messages m
            JOIN chains c ON m.chain_id = c.chain_id
            WHERE (CASE WHEN m.tag = 'openclaw-import' THEN m.id - 10000000000 ELSE m.id END) < @beforeSortKey AND c.archive_id IS NULL AND c.session_id = @sessionId AND m.type = 'text' {deletedFilter}",
            new { sessionId, beforeSortKey });
    }

    public async Task<List<MessageRecord>> GetActiveMessagesBeforeSortKey(string sessionId, long beforeSortKey, int limit, bool includeDeleted = false)
    {
        using var conn = CreateConnection();
        var deletedFilter = includeDeleted ? "" : "AND m.deleted_on IS NULL";
        var messages = await conn.QueryAsync<MessageRecord>($@"
            SELECT m.*, (CASE WHEN m.tag = 'openclaw-import' THEN m.id - 10000000000 ELSE m.id END) AS sort_key FROM messages m
            JOIN chains c ON m.chain_id = c.chain_id
            WHERE (CASE WHEN m.tag = 'openclaw-import' THEN m.id - 10000000000 ELSE m.id END) < @beforeSortKey AND c.archive_id IS NULL AND c.session_id = @sessionId {deletedFilter}
            ORDER BY sort_key DESC LIMIT @limit",
            new { sessionId, beforeSortKey, limit });
        return messages.Reverse().ToList();
    }

    public async Task<IEnumerable<MessageRecord>> GetActiveMessagesAfterSortKey(string sessionId, long afterSortKey, int limit = 200, bool includeDeleted = false)
    {
        using var conn = CreateConnection();
        var deletedFilter = includeDeleted ? "" : "AND m.deleted_on IS NULL";
        return await conn.QueryAsync<MessageRecord>($@"
            SELECT m.*, (CASE WHEN m.tag = 'openclaw-import' THEN m.id - 10000000000 ELSE m.id END) AS sort_key FROM messages m
            JOIN chains c ON m.chain_id = c.chain_id
            WHERE (CASE WHEN m.tag = 'openclaw-import' THEN m.id - 10000000000 ELSE m.id END) > @afterSortKey AND c.archive_id IS NULL AND c.session_id = @sessionId {deletedFilter}
            ORDER BY sort_key LIMIT @limit",
            new { sessionId, afterSortKey, limit });
    }

    // ── Message Marking ──

    public async Task<bool> ToggleMessageMark(long messageId)
    {
        using var conn = CreateConnection();
        await conn.ExecuteAsync(
            "UPDATE messages SET is_marked = CASE WHEN is_marked = 1 THEN 0 ELSE 1 END WHERE id = @messageId",
            new { messageId });
        return await conn.ExecuteScalarAsync<bool>(
            "SELECT is_marked FROM messages WHERE id = @messageId",
            new { messageId });
    }

    // ── Message Deletion ──

    public async Task<string> ToggleMessageDelete(long messageId)
    {
        using var conn = CreateConnection();
        var current = await conn.ExecuteScalarAsync<string>(
            "SELECT deleted_on FROM messages WHERE id = @messageId", new { messageId });
        string newValue;
        if (current == null)
        {
            newValue = DateTime.UtcNow.ToString("o");
            await conn.ExecuteAsync(
                "UPDATE messages SET deleted_on = @newValue WHERE id = @messageId",
                new { messageId, newValue });
        }
        else
        {
            newValue = null;
            await conn.ExecuteAsync(
                "UPDATE messages SET deleted_on = NULL WHERE id = @messageId",
                new { messageId });
        }
        return newValue;
    }

    public async Task<IEnumerable<MessageRecord>> GetMarkedMessages(string sessionId)
    {
        using var conn = CreateConnection();
        return await conn.QueryAsync<MessageRecord>(@"
            SELECT m.* FROM messages m
            JOIN chains c ON m.chain_id = c.chain_id
            WHERE c.session_id = @sessionId AND m.is_marked = 1
            ORDER BY m.id",
            new { sessionId });
    }

}