using System.Net.Http.Headers;
using Encoder;
using Microsoft.AspNetCore.Http.Features;
using Microsoft.AspNetCore.WebUtilities;

var builder = WebApplication.CreateBuilder(args);

//Services
builder.Services.AddOpenApi();
builder.Services.AddLogging();

string uploadsPath = builder.Configuration.GetSection("UploadsPath").Get<string>() ?? "./Uploads";
uploadsPath = uploadsPath.AbsoluteOrProcessPath();
Directory.CreateDirectory(uploadsPath); // Ensure the uploads directory exists

builder.Services.Configure<FFmpegOptions>(builder.Configuration.GetSection(FFmpegOptions.SectionName));
builder.Services.AddSingleton<EncoderService>();
builder.Services.AddHostedService<EncoderService>(p => p.GetRequiredService<EncoderService>());


var app = builder.Build();

if (app.Environment.IsDevelopment()) { app.MapOpenApi(); }

app.UseHttpsRedirection();

// Get a video file as multipart form data and schedule it for encoding
// Get video encoding settings from query parameters
// Returns the ID of the job handling the encoding
app.MapPost("encode", async context => {
    // Disable request size limit
    context.Features.Get<IHttpMaxRequestBodySizeFeature>()?.MaxRequestBodySize = null;
    
    // Fail fast, if EncoderService is not available don't bother processing the request
    var encSrv = context.RequestServices.GetService<EncoderService>();
    if (encSrv == null) {
        context.Response.StatusCode = 500;
        await context.Response.WriteAsync("Encoder service not available.");
        return;
    }
    
    // Parse multipart form data manually to handle large file uploads
    var request = context.Request;
    if (!request.HasFormContentType) {
        context.Response.StatusCode = 400;
        await context.Response.WriteAsync("Invalid content type. Expected multipart/form-data.");
        return;
    }
    
    Guid jobGuid = Guid.NewGuid();
    EncoderType encoderType = EncoderType.H264;
    string tempFilePath = Path.Combine(uploadsPath, jobGuid.ToString("D"));
    
    var boundary = Utils.GetBoundary(request.ContentType!);
    var reader = new MultipartReader(boundary!, context.Request.Body);
    MultipartSection? section;
    while ((section = await reader.ReadNextSectionAsync()) != null) {
        if(section.ContentDisposition is null) continue;
        
        var contentDisposition = ContentDispositionHeaderValue.Parse(section.ContentDisposition);
        switch (contentDisposition.Name) {
            case "encoder": {
                string encoderTypeStr = await section.ReadAsStringAsync();
                if (!Enum.TryParse<EncoderType>(encoderTypeStr, true, out encoderType)) {
                    context.Response.StatusCode = 400;
                    await context.Response.WriteAsync("Invalid or missing encoderType parameter.");
                    return;
                }
                continue;
            }
            case "video" when string.IsNullOrWhiteSpace(contentDisposition.FileName): {
                context.Response.StatusCode = 400;
                await context.Response.WriteAsync("No video file provided.");
                return;
            }
            case "video": {
                tempFilePath += Path.GetExtension(contentDisposition.FileName);
                await using var fstream = File.Create(tempFilePath);
                await section.Body.CopyToAsync(fstream);
                continue;
            }
        }
    }
    
    var job = new EncodingJob(jobGuid, tempFilePath, encoderType);
    encSrv.EnqueueJob(job);
    
    context.Response.StatusCode = 200;
    await context.Response.WriteAsJsonAsync(new { JobId = jobGuid });
}).WithFormOptions(multipartBodyLengthLimit: 1_073_741_824L*64L);

app.MapGet("status", (context) => {
    var encSrv = context.RequestServices.GetService<EncoderService>();
    if (encSrv == null) {
        context.Response.StatusCode = 500;
        return context.Response.WriteAsync("Encoder service not available.");
    }

    var jobs = encSrv.GetJobs().ToArray();
    
    context.Response.StatusCode = 200;
    return context.Response.WriteAsJsonAsync(jobs);
});

// Check the status of an encoding job by its ID
app.MapGet("status/{jobId:guid}", (HttpContext context, Guid jobId) => {
    var encSrv = context.RequestServices.GetService<EncoderService>();
    if (encSrv == null) return Results.InternalServerError();
    
    var job = encSrv.GetJobStatus(jobId);
    if (job == null) {
        return Results.NotFound(new { Message = "Job not found." });
    }
    
    return Results.Ok(new { 
        JobId = job.Id, 
        Status = job.Status.ToString(),
        job.CreatedAt,
        job.CompletedAt 
    });
});

app.MapGet("file/{jobId:guid}", (HttpContext context, Guid jobId) => {
    var encSrv = context.RequestServices.GetService<EncoderService>();
    if (encSrv == null) return Results.InternalServerError();
    
    var job = encSrv.GetJobStatus(jobId);
    if (job == null) return Results.NotFound(new { Message = "Job not found." });

    if (job.Status != JobStatus.Completed) return Results.BadRequest(new { Message = "Job is not completed yet." });

    var filePath = job.EncodedFilePath;
    if (!File.Exists(filePath)) return Results.NotFound(new { Message = "Encoded file not found." });

    var fileBytes = File.ReadAllBytes(filePath);
    return Results.File(fileBytes, "video/mp4", Path.GetFileName(filePath), enableRangeProcessing:true);
});

app.MapOpenApi("openapi.json");

app.Run();