using System.Text.Json.Nodes;
using System.Text.RegularExpressions;
using Microsoft.Extensions.Options;
using Moonlight.Api.Configuration;
using Moonlight.Api.Models;

namespace Moonlight.Api.Services;

public partial class VersionService
{
    private readonly IOptions<VersionOptions> Options;
    private readonly IHttpClientFactory HttpClientFactory;

    private const string VersionPath = "/app/version";
    private const string GiteaServer = "https://git.battlestati.one";
    private const string GiteaRepository = "Moonlight-Panel/Moonlight";

    [GeneratedRegex(@"^v(?!1(\.|$))\d+\.[A-Za-z0-9]+(\.[A-Za-z0-9]+)*$")]
    private static partial Regex RegexFilter();

    public VersionService(
        IOptions<VersionOptions> options,
        IHttpClientFactory httpClientFactory
    )
    {
        Options = options;
        HttpClientFactory = httpClientFactory;
    }

    public async Task<MoonlightVersion[]> GetVersionsAsync()
    {
        if (Options.Value.OfflineMode)
            return [];
        
        var versions = new List<MoonlightVersion>();
        var httpClient = HttpClientFactory.CreateClient();

        // Tags
        const string tagsPath = $"{GiteaServer}/api/v1/repos/{GiteaRepository}/tags";

        await using var tagsJsonStream = await httpClient.GetStreamAsync(tagsPath);
        var tagsJson = await JsonNode.ParseAsync(tagsJsonStream);

        if (tagsJson != null)
        {
            foreach (var node in tagsJson.AsArray())
            {
                if (node == null)
                    continue;

                var name = node["name"]?.GetValue<string>() ?? "N/A";
                var createdAt = node["createdAt"]?.GetValue<DateTimeOffset>() ?? DateTimeOffset.MinValue;
                
                if(!RegexFilter().IsMatch(name))
                    continue;

                versions.Add(new MoonlightVersion(
                    name,
                    name.EndsWith('b'),
                    false,
                    createdAt
                ));
            }
        }
        
        // Branches
        const string branchesPath = $"{GiteaServer}/api/v1/repos/{GiteaRepository}/branches";

        await using var branchesJsonStream = await httpClient.GetStreamAsync(branchesPath);
        var branchesJson = await JsonNode.ParseAsync(branchesJsonStream);

        if (branchesJson != null)
        {
            foreach (var node in branchesJson.AsArray())
            {
                if (node == null)
                    continue;

                var name = node["name"]?.GetValue<string>() ?? "N/A";
                var commit = node["commit"];

                if (commit == null)
                    continue;

                var createdAt = commit["timestamp"]?.GetValue<DateTimeOffset>() ?? DateTimeOffset.MinValue;
                
                if(!RegexFilter().IsMatch(name))
                    continue;

                versions.Add(new MoonlightVersion(
                    name,
                    name.EndsWith('b'),
                    true,
                    createdAt
                ));
            }
        }

        return versions.ToArray();
    }

    public async Task<MoonlightVersion> GetInstanceVersionAsync()
    {
        var knownVersions = await GetVersionsAsync();

        string versionIdentifier;

        if (!string.IsNullOrWhiteSpace(Options.Value.CurrentOverride))
            versionIdentifier = Options.Value.CurrentOverride;
        else
        {
            if (File.Exists(VersionPath))
                versionIdentifier = await File.ReadAllTextAsync(VersionPath);
            else
                versionIdentifier = "unknown";
        }

        var version = knownVersions.FirstOrDefault(x => x.Identifier == versionIdentifier);

        if (version != null)
            return version;

        return new MoonlightVersion(
            versionIdentifier,
            false,
            false,
            DateTimeOffset.UtcNow
        );
    }

    public async Task<MoonlightVersion?> GetLatestVersionAsync()
    {
        var versions = await GetVersionsAsync();

        return versions
            .Where(x => x is { IsDevelopment: false, IsPreRelease: false })
            .OrderByDescending(x => x.CreatedAt)
            .FirstOrDefault();
    }
}