using System.Net;
using System.Text.Json;
using System.Text.Json.Serialization;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;

namespace mws.backend.dotnet.infrastructure.CloudFile;

public interface ICloudFileHttpClient
{
    Task<CloudFileMetadata?> UploadAsync(string bucket, string key, string contentType, Stream body, CancellationToken ct);
    Task<Stream> DownloadAsync(string bucket, string key, CancellationToken ct);
    Task<bool> ExistsAsync(string bucket, string key, CancellationToken ct);
    Task DeleteAsync(string bucket, string key, CancellationToken ct);
    Task EnsureBucketAsync(string bucket, CancellationToken ct);
}

public class CloudFileHttpClient(
    HttpClient http,
    IOptions<CloudFileOptions> opt,
    ILogger<CloudFileHttpClient> log) : ICloudFileHttpClient
{
    private static readonly JsonSerializerOptions Json = new()
    {
        PropertyNamingPolicy = JsonNamingPolicy.CamelCase
    };

    private HttpRequestMessage Req(HttpMethod method, string url)
    {
        var request = new HttpRequestMessage(method, url);
        request.Headers.Add("X-API-Key", opt.Value.ApiKey);
        return request;
    }

    public async Task<CloudFileMetadata?> UploadAsync(string bucket, string key, string contentType, Stream body, CancellationToken ct)
    {
        using var form = new MultipartFormDataContent
        {
            { new StreamContent(body), "file", key },
            { new StringContent(bucket), "bucket" },
            { new StringContent(key), "key" }
        };

        var request = Req(HttpMethod.Post, "/api/files/upload");
        request.Content = form;

        var resp = await http.SendAsync(request, ct);
        var responseText = await resp.Content.ReadAsStringAsync(ct);

        if (!resp.IsSuccessStatusCode)
        {
            log.LogWarning("CloudFile upload failed {Status}: {Body}", resp.StatusCode, responseText);
            resp.EnsureSuccessStatusCode();
        }

        var dto = JsonSerializer.Deserialize<CloudFileUploadResponse>(responseText, Json);
        return dto?.Metadata;
    }

    public async Task<Stream> DownloadAsync(string bucket, string key, CancellationToken ct)
    {
        var request = Req(HttpMethod.Get, $"/api/files/download/{bucket}/{Uri.EscapeDataString(key)}");
        var resp = await http.SendAsync(request, HttpCompletionOption.ResponseHeadersRead, ct);

        if (resp.StatusCode == HttpStatusCode.NotFound)
        {
            return Stream.Null;
        }

        resp.EnsureSuccessStatusCode();
        return await resp.Content.ReadAsStreamAsync(ct);
    }

    public async Task<bool> ExistsAsync(string bucket, string key, CancellationToken ct)
    {
        var request = Req(HttpMethod.Get, $"/api/files/{bucket}/metadata/{Uri.EscapeDataString(key)}");
        var resp = await http.SendAsync(request, HttpCompletionOption.ResponseHeadersRead, ct);
        return resp.IsSuccessStatusCode;
    }

    public async Task DeleteAsync(string bucket, string key, CancellationToken ct)
    {
        var request = Req(HttpMethod.Delete, $"/api/files/{bucket}/{Uri.EscapeDataString(key)}");
        var resp = await http.SendAsync(request, ct);

        if (resp.StatusCode != HttpStatusCode.NotFound)
        {
            resp.EnsureSuccessStatusCode();
        }
    }

    public async Task EnsureBucketAsync(string bucket, CancellationToken ct)
    {
        var request = Req(HttpMethod.Post, "/api/buckets");
        var json = JsonSerializer.Serialize(new { name = bucket }, Json);
        request.Content = new StringContent(json, System.Text.Encoding.UTF8, "application/json");

        var resp = await http.SendAsync(request, ct);
        var responseText = await resp.Content.ReadAsStringAsync(ct);

        if (!resp.IsSuccessStatusCode && resp.StatusCode != HttpStatusCode.BadRequest)
        {
            log.LogWarning("CloudFile ensureBucket failed {Status}: {Body}", resp.StatusCode, responseText);
            resp.EnsureSuccessStatusCode();
        }
    }
}

public class CloudFileUploadResponse
{
    public bool Success { get; set; }
    public CloudFileMetadata? Metadata { get; set; }
}

public class CloudFileMetadata
{
    [JsonPropertyName("fileId")]
    public string FileId { get; set; } = string.Empty;

    [JsonPropertyName("fileName")]
    public string FileName { get; set; } = string.Empty;

    [JsonPropertyName("extension")]
    public string Extension { get; set; } = string.Empty;

    [JsonPropertyName("contentType")]
    public string ContentType { get; set; } = string.Empty;

    [JsonPropertyName("size")]
    public long Size { get; set; }

    [JsonPropertyName("bucket")]
    public string Bucket { get; set; } = string.Empty;

    [JsonPropertyName("key")]
    public string Key { get; set; } = string.Empty;

    [JsonPropertyName("contentHash")]
    public string ContentHash { get; set; } = string.Empty;

    [JsonPropertyName("createdAt")]
    public DateTime CreatedAt { get; set; }

    [JsonPropertyName("modifiedAt")]
    public DateTime ModifiedAt { get; set; }
}