using System.Globalization;
using System.Text.Json;
using LanMountainDesktop.PluginSdk;

namespace LanMountainDesktop.PluginMarketplace;

internal static class AirAppMarketDefaults
{
    public const string DefaultIndexUrl =
        "https://raw.githubusercontent.com/wwiinnddyy/LanMountainDesktop/main/airappmarket/index.json";
}

internal enum AirAppMarketLoadSource
{
    Network = 0,
    Cache = 1
}

internal enum AirAppMarketInstallState
{
    NotInstalled = 0,
    UpdateAvailable = 1,
    Installed = 2
}

internal sealed record AirAppMarketLoadResult(
    bool Success,
    AirAppMarketIndexDocument? Document,
    AirAppMarketLoadSource? Source,
    string? WarningMessage,
    string? ErrorMessage);

internal sealed record AirAppMarketInstallResult(
    bool Success,
    PluginPackageInstallResult? InstallResult,
    string? ErrorMessage);

internal sealed class AirAppMarketIndexDocument
{
    private static readonly JsonSerializerOptions SerializerOptions = new()
    {
        PropertyNameCaseInsensitive = true,
        ReadCommentHandling = JsonCommentHandling.Skip,
        AllowTrailingCommas = true
    };

    public string SchemaVersion { get; init; } = string.Empty;

    public string SourceId { get; init; } = string.Empty;

    public string SourceName { get; init; } = string.Empty;

    public DateTimeOffset GeneratedAt { get; init; }

    public List<AirAppMarketPluginEntry> Plugins { get; init; } = [];

    public static AirAppMarketIndexDocument Load(string json, string sourceName)
    {
        ArgumentException.ThrowIfNullOrWhiteSpace(json);
        ArgumentException.ThrowIfNullOrWhiteSpace(sourceName);

        var document = JsonSerializer.Deserialize<AirAppMarketIndexDocument>(
            json.TrimStart('\uFEFF'),
            SerializerOptions);

        if (document is null)
        {
            throw new InvalidOperationException($"Failed to parse market index '{sourceName}'.");
        }

        return document.ValidateAndNormalize(sourceName);
    }

    private AirAppMarketIndexDocument ValidateAndNormalize(string sourceName)
    {
        var plugins = Plugins ?? [];
        var normalizedPlugins = new List<AirAppMarketPluginEntry>(plugins.Count);
        var seenIds = new HashSet<string>(StringComparer.OrdinalIgnoreCase);

        foreach (var plugin in plugins)
        {
            var normalizedPlugin = plugin.ValidateAndNormalize(sourceName);
            if (!seenIds.Add(normalizedPlugin.Id))
            {
                throw new InvalidOperationException(
                    $"Market index '{sourceName}' contains duplicate plugin id '{normalizedPlugin.Id}'.");
            }

            normalizedPlugins.Add(normalizedPlugin);
        }

        return new AirAppMarketIndexDocument
        {
            SchemaVersion = RequireValue(SchemaVersion, nameof(SchemaVersion), sourceName),
            SourceId = RequireValue(SourceId, nameof(SourceId), sourceName),
            SourceName = RequireValue(SourceName, nameof(SourceName), sourceName),
            GeneratedAt = GeneratedAt == default
                ? throw new InvalidOperationException($"Market index '{sourceName}' is missing a valid generatedAt timestamp.")
                : GeneratedAt,
            Plugins = normalizedPlugins
                .OrderBy(plugin => plugin.Name, StringComparer.OrdinalIgnoreCase)
                .ToList()
        };
    }

    private static string RequireValue(string? value, string propertyName, string sourceName)
    {
        var normalized = NormalizeValue(value);
        if (string.IsNullOrWhiteSpace(normalized))
        {
            throw new InvalidOperationException($"Market index '{sourceName}' is missing required property '{propertyName}'.");
        }

        return normalized;
    }

    internal static string? NormalizeValue(string? value)
    {
        return string.IsNullOrWhiteSpace(value) ? null : value.Trim();
    }

    internal static string NormalizeVersion(string? value, string propertyName, string sourceName)
    {
        var normalized = RequireValue(value, propertyName, sourceName);
        if (!TryParseVersion(normalized, out _))
        {
            throw new InvalidOperationException(
                $"Market index '{sourceName}' declares invalid version '{normalized}' for '{propertyName}'.");
        }

        return normalized;
    }

    internal static void EnsureUrl(string url, string propertyName, string sourceName)
    {
        if (!Uri.TryCreate(url, UriKind.Absolute, out var uri) ||
            (uri.Scheme != Uri.UriSchemeHttp && uri.Scheme != Uri.UriSchemeHttps))
        {
            throw new InvalidOperationException(
                $"Market index '{sourceName}' declares invalid URL '{url}' for '{propertyName}'.");
        }
    }

    internal static bool TryParseVersion(string? value, out Version? version)
    {
        version = null;
        var normalized = NormalizeValue(value);
        if (string.IsNullOrWhiteSpace(normalized))
        {
            return false;
        }

        if (normalized.StartsWith("v", StringComparison.OrdinalIgnoreCase))
        {
            normalized = normalized[1..];
        }

        var separatorIndex = normalized.IndexOfAny(['-', '+', ' ']);
        if (separatorIndex > 0)
        {
            normalized = normalized[..separatorIndex];
        }

        if (!Version.TryParse(normalized, out var parsed))
        {
            return false;
        }

        version = new Version(
            Math.Max(0, parsed.Major),
            Math.Max(0, parsed.Minor),
            Math.Max(0, parsed.Build));
        return true;
    }
}

internal sealed class AirAppMarketPluginEntry
{
    public string Id { get; init; } = string.Empty;

    public string Name { get; init; } = string.Empty;

    public string Description { get; init; } = string.Empty;

    public string Author { get; init; } = string.Empty;

    public string Version { get; init; } = string.Empty;

    public string ApiVersion { get; init; } = string.Empty;

    public string MinHostVersion { get; init; } = string.Empty;

    public string DownloadUrl { get; init; } = string.Empty;

    public string Sha256 { get; init; } = string.Empty;

    public long PackageSizeBytes { get; init; }

    public string IconUrl { get; init; } = string.Empty;

    public string HomepageUrl { get; init; } = string.Empty;

    public string RepositoryUrl { get; init; } = string.Empty;

    public List<string> Tags { get; init; } = [];

    public DateTimeOffset PublishedAt { get; init; }

    public DateTimeOffset UpdatedAt { get; init; }

    public string ReleaseNotes { get; init; } = string.Empty;

    public AirAppMarketPluginEntry ValidateAndNormalize(string sourceName)
    {
        var normalizedTags = (Tags ?? [])
            .Select(tag => AirAppMarketIndexDocument.NormalizeValue(tag))
            .Where(tag => !string.IsNullOrWhiteSpace(tag))
            .Select(tag => tag!)
            .Distinct(StringComparer.OrdinalIgnoreCase)
            .OrderBy(tag => tag, StringComparer.OrdinalIgnoreCase)
            .ToList();

        var normalizedSha = AirAppMarketIndexDocument.NormalizeValue(Sha256)?.ToLowerInvariant()
            ?? throw new InvalidOperationException(
                $"Market index '{sourceName}' is missing required property '{nameof(Sha256)}'.");

        if (normalizedSha.Length != 64 || normalizedSha.Any(ch => !Uri.IsHexDigit(ch)))
        {
            throw new InvalidOperationException(
                $"Market index '{sourceName}' declares invalid SHA-256 '{normalizedSha}' for plugin '{Id}'.");
        }

        var normalizedDownloadUrl = AirAppMarketIndexDocument.NormalizeValue(DownloadUrl)
            ?? throw new InvalidOperationException(
                $"Market index '{sourceName}' is missing required property '{nameof(DownloadUrl)}'.");
        var normalizedIconUrl = AirAppMarketIndexDocument.NormalizeValue(IconUrl)
            ?? throw new InvalidOperationException(
                $"Market index '{sourceName}' is missing required property '{nameof(IconUrl)}'.");
        var normalizedHomepageUrl = AirAppMarketIndexDocument.NormalizeValue(HomepageUrl)
            ?? throw new InvalidOperationException(
                $"Market index '{sourceName}' is missing required property '{nameof(HomepageUrl)}'.");
        var normalizedRepositoryUrl = AirAppMarketIndexDocument.NormalizeValue(RepositoryUrl)
            ?? throw new InvalidOperationException(
                $"Market index '{sourceName}' is missing required property '{nameof(RepositoryUrl)}'.");

        AirAppMarketIndexDocument.EnsureUrl(normalizedDownloadUrl, nameof(DownloadUrl), sourceName);
        AirAppMarketIndexDocument.EnsureUrl(normalizedIconUrl, nameof(IconUrl), sourceName);
        AirAppMarketIndexDocument.EnsureUrl(normalizedHomepageUrl, nameof(HomepageUrl), sourceName);
        AirAppMarketIndexDocument.EnsureUrl(normalizedRepositoryUrl, nameof(RepositoryUrl), sourceName);

        if (PackageSizeBytes <= 0)
        {
            throw new InvalidOperationException(
                $"Market index '{sourceName}' declares invalid packageSizeBytes '{PackageSizeBytes}' for plugin '{Id}'.");
        }

        if (PublishedAt == default || UpdatedAt == default)
        {
            throw new InvalidOperationException(
                $"Market index '{sourceName}' is missing valid publish timestamps for plugin '{Id}'.");
        }

        return new AirAppMarketPluginEntry
        {
            Id = AirAppMarketIndexDocument.NormalizeValue(Id)
                ?? throw new InvalidOperationException($"Market index '{sourceName}' is missing plugin id."),
            Name = AirAppMarketIndexDocument.NormalizeValue(Name)
                ?? throw new InvalidOperationException($"Market index '{sourceName}' is missing plugin name."),
            Description = AirAppMarketIndexDocument.NormalizeValue(Description)
                ?? throw new InvalidOperationException($"Market index '{sourceName}' is missing plugin description."),
            Author = AirAppMarketIndexDocument.NormalizeValue(Author)
                ?? throw new InvalidOperationException($"Market index '{sourceName}' is missing plugin author."),
            Version = AirAppMarketIndexDocument.NormalizeVersion(Version, nameof(Version), sourceName),
            ApiVersion = AirAppMarketIndexDocument.NormalizeVersion(ApiVersion, nameof(ApiVersion), sourceName),
            MinHostVersion = AirAppMarketIndexDocument.NormalizeVersion(MinHostVersion, nameof(MinHostVersion), sourceName),
            DownloadUrl = normalizedDownloadUrl,
            Sha256 = normalizedSha,
            PackageSizeBytes = PackageSizeBytes,
            IconUrl = normalizedIconUrl,
            HomepageUrl = normalizedHomepageUrl,
            RepositoryUrl = normalizedRepositoryUrl,
            Tags = normalizedTags,
            PublishedAt = PublishedAt,
            UpdatedAt = UpdatedAt,
            ReleaseNotes = AirAppMarketIndexDocument.NormalizeValue(ReleaseNotes)
                ?? throw new InvalidOperationException($"Market index '{sourceName}' is missing release notes for plugin '{Id}'.")
        };
    }

    public string GetVersionSummary()
    {
        return string.Format(
            CultureInfo.InvariantCulture,
            "v{0} | API {1} | Host >= {2}",
            Version,
            ApiVersion,
            MinHostVersion);
    }
}