using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Gott.Models;
using Gott.Services;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Routing;

namespace Gott.Endpoints;

public static class HistoryEndpoint
{
    public static void MapHistoryEndpoint(this IEndpointRouteBuilder app)
    {
        app.MapGet("/api/history", HandleHistory);
        app.MapGet("/api/history/poll", HandlePoll);
        app.MapPost("/api/archive", HandleArchive);
        app.MapGet("/api/archives", HandleListArchives);
        app.MapGet("/api/archive/{archiveId}", HandleGetArchive);
        app.MapGet("/api/attachments/{messageId}", HandleGetAttachments);
        app.MapGet("/api/chains/{chainId}", HandleGetChain);
    }

    private static async Task HandleHistory(HttpContext ctx, DatabaseService db)
    {
        var sessionId = ctx.Request.Query["sessionId"].FirstOrDefault();
        if (string.IsNullOrEmpty(sessionId))
        {
            ctx.Response.StatusCode = 400;
            await ctx.Response.WriteAsJsonAsync(new { error = "sessionId required" });
            return;
        }

        var chains = await db.GetActiveChains(sessionId);

        var result = new List<object>();
        foreach (var chain in chains)
        {
            var messages = await db.GetChainMessages(chain.ChainId);
            result.Add(new { chain, messages });
        }

        await ctx.Response.WriteAsJsonAsync(result);
    }

    private static async Task HandlePoll(HttpContext ctx, DatabaseService db)
    {
        var sessionId = ctx.Request.Query["sessionId"].FirstOrDefault();
        var afterStr = ctx.Request.Query["afterId"].FirstOrDefault();
        var afterId = long.TryParse(afterStr, out var a) ? a : 0;

        if (string.IsNullOrEmpty(sessionId))
        {
            ctx.Response.StatusCode = 400;
            return;
        }

        var messages = await db.GetActiveMessagesAfterId(sessionId, afterId);
        await ctx.Response.WriteAsJsonAsync(messages);
    }

    private static async Task HandleArchive(HttpContext ctx, DatabaseService db)
    {
        var sessionId = ctx.Request.Query["sessionId"].FirstOrDefault();
        if (string.IsNullOrEmpty(sessionId))
        {
            ctx.Response.StatusCode = 400;
            return;
        }

        var archive = await db.CreateArchive(sessionId);
        if (archive == null)
        {
            ctx.Response.StatusCode = 204;
            return;
        }
        await ctx.Response.WriteAsJsonAsync(archive);
    }

    private static async Task HandleListArchives(HttpContext ctx, DatabaseService db)
    {
        var sessionId = ctx.Request.Query["sessionId"].FirstOrDefault();
        if (string.IsNullOrEmpty(sessionId))
        {
            ctx.Response.StatusCode = 400;
            return;
        }

        var archives = await db.GetArchives(sessionId);
        await ctx.Response.WriteAsJsonAsync(archives);
    }

    private static async Task HandleGetAttachments(HttpContext ctx, DatabaseService db)
    {
        var messageIdStr = ctx.Request.RouteValues["messageId"]?.ToString();
        if (!long.TryParse(messageIdStr, out var messageId))
        {
            ctx.Response.StatusCode = 400;
            return;
        }

        var attachments = await db.GetAttachments(messageId);
        // Ohne Base64-Data zurückgeben (zu groß), stattdessen als separater Download
        var result = new List<object>();
        foreach (var att in attachments)
        {
            result.Add(new
            {
                att.Id,
                att.MessageId,
                att.Type,
                att.MediaType,
                att.FileName,
                att.Data,
                att.CreatedAt
            });
        }
        await ctx.Response.WriteAsJsonAsync(result);
    }

    private static async Task HandleGetChain(HttpContext ctx, DatabaseService db)
    {
        var chainId = ctx.Request.RouteValues["chainId"]?.ToString();
        if (string.IsNullOrEmpty(chainId))
        {
            ctx.Response.StatusCode = 400;
            return;
        }

        var chain = await db.GetChain(chainId);
        if (chain == null)
        {
            ctx.Response.StatusCode = 404;
            return;
        }

        await ctx.Response.WriteAsJsonAsync(chain);
    }

    private static async Task HandleGetArchive(HttpContext ctx, DatabaseService db)
    {
        var archiveId = ctx.Request.RouteValues["archiveId"]?.ToString();
        if (string.IsNullOrEmpty(archiveId))
        {
            ctx.Response.StatusCode = 400;
            return;
        }

        var chains = await db.GetArchiveChains(archiveId);
        var result = new List<object>();
        foreach (var chain in chains)
        {
            var messages = await db.GetChainMessages(chain.ChainId);
            result.Add(new { chain, messages });
        }

        await ctx.Response.WriteAsJsonAsync(result);
    }
}