using System.Diagnostics;
using System.Security.Cryptography;
using YD_Event.Application.Auth;
using YD_Event.Application.Common;

namespace YD_Event.Application.AppUpdate;

/// <summary>内部 Android 裁判端 APK 发布与升级检查。</summary>
[ApiDescriptionSettings("裁判端升级")]
[Route("api/app-updates")]
[Authorize]
public class AppUpdateController : IDynamicApiController
{
    private const string PackageName = "com.yd.event.yd_pattern_scoring_system";
    private const long MaxApkSize = 200L * 1024 * 1024;
    private readonly ISqlSugarRepository<JudgeAppRelease> _releases;
    private readonly AuthManager _auth;
    private readonly IIdGenerator _ids;
    private readonly FileService _files;
    private readonly string _channel;

    public AppUpdateController(ISqlSugarRepository<JudgeAppRelease> releases,
        AuthManager auth, IIdGenerator ids, FileService files)
    {
        _releases = releases;
        _auth = auth;
        _ids = ids;
        _files = files;
        _channel = Environment.GetEnvironmentVariable("APP_UPDATE_CHANNEL")?.Trim().ToLowerInvariant() ?? "production";
    }

    /// <summary>登录前即可查询当前环境的最新 APK。</summary>
    [HttpGet("latest")]
    [AllowAnonymous]
    public async Task<object> Latest()
    {
        var release = await _releases.AsQueryable()
            .Where(x => x.Channel == _channel && x.ReleaseStatus == 1 && x.PackageName == PackageName)
            .OrderByDescending(x => x.VersionCode).FirstAsync();
        return release == null ? new { available = false } : new
        {
            available = true, release.Id, release.PackageName, release.VersionCode,
            release.VersionName, release.NotesZh, release.NotesEn,
            release.IsMandatory, release.FileSize, release.Sha256,
            release.CertificateSha256, downloadUrl = $"/api/app-updates/download/{release.Id}",
            release.PublishedTime
        };
    }

    /// <summary>只允许下载当前环境已发布的版本，文件由现有对象存储分发。</summary>
    [HttpGet("download/{id:long}")]
    [AllowAnonymous]
    public async Task<IActionResult> Download(long id)
    {
        var release = await _releases.GetFirstAsync(x => x.Id == id && x.Channel == _channel &&
            x.PackageName == PackageName && x.ReleaseStatus == 1);
        if (release == null || string.IsNullOrWhiteSpace(release.FileUrl)) return new NotFoundResult();
        return new RedirectResult(release.FileUrl);
    }

    [HttpGet("admin/releases")]
    public async Task<object> Releases()
    {
        EnsureAdmin();
        return await _releases.AsQueryable().Where(x => x.Channel == _channel)
            .OrderByDescending(x => x.VersionCode).ToListAsync();
    }

    [HttpPost("admin/upload")]
    [DisplayName("上传裁判端 APK 草稿")]
    [RequestSizeLimit(MaxApkSize + 1024 * 1024)]
    [RequestFormLimits(MultipartBodyLengthLimit = MaxApkSize + 1024 * 1024)]
    public async Task<JudgeAppRelease> Upload([FromForm] IFormFile file,
        [FromForm] string notesZh, [FromForm] string? notesEn = null,
        [FromForm] bool isMandatory = false)
    {
        EnsureAdmin();
        if (file == null || file.Length < 1024 || file.Length > MaxApkSize ||
            !string.Equals(Path.GetExtension(file.FileName), ".apk", StringComparison.OrdinalIgnoreCase))
            throw Oops.Bah("仅允许上传 1KB 至 200MB 的 APK");
        if (string.IsNullOrWhiteSpace(notesZh)) throw Oops.Bah("请填写中文更新说明");
        var temp = Path.Combine(Path.GetTempPath(), $"yd-app-release-{Guid.NewGuid():N}.apk");
        try
        {
            await using (var output = System.IO.File.Create(temp))
            await using (var source = file.OpenReadStream())
                await source.CopyToAsync(output);
            await using (var input = System.IO.File.OpenRead(temp))
            {
                var magic = new byte[4];
                if (await input.ReadAsync(magic) != 4 || magic[0] != 0x50 || magic[1] != 0x4B || magic[2] != 0x03 || magic[3] != 0x04)
                    throw Oops.Bah("文件不是有效的 APK/ZIP");
            }
            var metadata = await InspectApk(temp);
            if (metadata.PackageName != PackageName || metadata.VersionCode <= 0)
                throw Oops.Bah("APK 包名或版本号不正确");
            var expected = Environment.GetEnvironmentVariable("APP_RELEASE_CERT_SHA256")?.Trim().ToUpperInvariant();
            if (expected == null || !Regex.IsMatch(expected, "^[0-9A-F]{64}$"))
                throw Oops.Bah("服务器未配置正式签名指纹，禁止发布");
            if (metadata.CertificateSha256 != expected) throw Oops.Bah("APK 签名与正式签名不一致");
            var existing = await _releases.GetFirstAsync(x => x.Channel == _channel && x.PackageName == PackageName && x.VersionCode == metadata.VersionCode);
            if (existing != null) throw Oops.Bah("该版本号已存在，请使用新的递增版本号");
            await using var hashStream = System.IO.File.OpenRead(temp);
            var sha = Convert.ToHexString(await SHA256.HashDataAsync(hashStream));
            await using var uploadStream = System.IO.File.OpenRead(temp);
            var release = new JudgeAppRelease
            {
                Id = _ids.NextId(), Channel = _channel, PackageName = PackageName,
                VersionCode = metadata.VersionCode, VersionName = metadata.VersionName,
                NotesZh = notesZh?.Trim() ?? string.Empty, NotesEn = notesEn?.Trim() ?? string.Empty,
                IsMandatory = isMandatory, FileSize = uploadStream.Length,
                Sha256 = sha, CertificateSha256 = metadata.CertificateSha256,
                FileUrl = await _files.UploadFileStreamAsync($"app-releases/{_channel}/{Guid.NewGuid():N}.apk", uploadStream),
                ReleaseStatus = 0, CreatedUserId = _auth.UserId, CreatedTime = DateTime.UtcNow
            };
            await _releases.InsertAsync(release);
            return release;
        }
        finally { if (System.IO.File.Exists(temp)) System.IO.File.Delete(temp); }
    }

    [HttpPost("admin/{id:long}/publish")]
    public async Task<JudgeAppRelease> Publish(long id)
    {
        EnsureAdmin();
        var release = await FindOwn(id);
        if (release.ReleaseStatus != 0) throw Oops.Bah("只有草稿可以发布");
        if (_channel == "production" &&
            (!Uri.TryCreate(release.FileUrl, UriKind.Absolute, out var fileUri) || fileUri.Scheme != Uri.UriSchemeHttps))
            throw Oops.Bah("正式环境的 APK 下载地址必须为 HTTPS");
        var latest = await _releases.AsQueryable()
            .Where(x => x.Channel == _channel && x.PackageName == PackageName && x.ReleaseStatus != 0)
            .OrderByDescending(x => x.VersionCode).FirstAsync();
        if (latest != null && release.VersionCode <= latest.VersionCode)
            throw Oops.Bah("版本号必须高于当前已发布版本");
        release.ReleaseStatus = 1;
        release.PublishedUserId = _auth.UserId;
        release.PublishedTime = DateTime.UtcNow;
        await _releases.UpdateAsync(release);
        return release;
    }

    [HttpPost("admin/{id:long}/withdraw")]
    public async Task<JudgeAppRelease> Withdraw(long id)
    {
        EnsureAdmin();
        var release = await FindOwn(id);
        if (release.ReleaseStatus != 1) throw Oops.Bah("只有已发布版本可以撤回");
        release.ReleaseStatus = 2;
        release.WithdrawnUserId = _auth.UserId;
        release.WithdrawnTime = DateTime.UtcNow;
        await _releases.UpdateAsync(release);
        return release;
    }

    private void EnsureAdmin()
    {
        if (!_auth.IsSuperAdmin) throw Oops.Bah("仅超级管理员可管理裁判端版本");
    }

    private async Task<JudgeAppRelease> FindOwn(long id)
    {
        var release = await _releases.GetFirstAsync(x => x.Id == id && x.Channel == _channel);
        return release ?? throw Oops.Bah("版本不存在");
    }

    private static async Task<(string PackageName, int VersionCode, string VersionName, string CertificateSha256)> InspectApk(string path)
    {
        var directory = Environment.GetEnvironmentVariable("ANDROID_BUILD_TOOLS_DIR");
        if (string.IsNullOrWhiteSpace(directory)) throw Oops.Bah("服务器未配置 Android build-tools，禁止盲目发布");
        var aapt = Path.Combine(directory, OperatingSystem.IsWindows() ? "aapt.exe" : "aapt");
        var signer = Path.Combine(directory, OperatingSystem.IsWindows() ? "apksigner.bat" : "apksigner");
        var badging = await RunTool(aapt, "dump", "badging", path);
        var match = Regex.Match(badging, "package: name='([^']+)' versionCode='([0-9]+)' versionName='([^']*)'");
        if (!match.Success) throw Oops.Bah("无法读取 APK 包名及版本");
        var result = await RunTool(signer, "verify", "--print-certs", path);
        var digest = Regex.Match(result, "certificate SHA-256 digest: ([0-9a-fA-F]{64})");
        if (!digest.Success) throw Oops.Bah("无法验证 APK 签名");
        return (match.Groups[1].Value, int.Parse(match.Groups[2].Value), match.Groups[3].Value, digest.Groups[1].Value.ToUpperInvariant());
    }

    private static async Task<string> RunTool(string executable, params string[] arguments)
    {
        if (!System.IO.File.Exists(executable)) throw Oops.Bah("Android build-tools 不完整");
        ProcessStartInfo start;
        if (OperatingSystem.IsWindows() && executable.EndsWith(".bat", StringComparison.OrdinalIgnoreCase))
        {
            start = new ProcessStartInfo("cmd.exe") { RedirectStandardOutput = true, RedirectStandardError = true, UseShellExecute = false };
            start.ArgumentList.Add("/d");
            start.ArgumentList.Add("/c");
            start.ArgumentList.Add("\"" + executable + "\" " + string.Join(" ", arguments.Select(x => "\"" + x.Replace("\"", "") + "\"")));
        }
        else
        {
            start = new ProcessStartInfo(executable) { RedirectStandardOutput = true, RedirectStandardError = true, UseShellExecute = false };
            foreach (var argument in arguments) start.ArgumentList.Add(argument);
        }
        using var process = Process.Start(start) ?? throw Oops.Bah("无法启动 APK 检查工具");
        var output = process.StandardOutput.ReadToEndAsync();
        var error = process.StandardError.ReadToEndAsync();
        using var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(30));
        try { await process.WaitForExitAsync(timeout.Token); }
        catch (OperationCanceledException) { process.Kill(entireProcessTree: true); throw Oops.Bah("APK 检查超时"); }
        if (process.ExitCode != 0) throw Oops.Bah("APK 检查失败：" + (await error).Trim());
        return await output;
    }
}