using sh.actions.package_cleanup.Models;

namespace sh.actions.package_cleanup.Service;

public class PackageService(IConfiguration configuration, IGiteaPackageService packageService) : IPackageService
{
    public async Task<List<GiteaPackage>> GetFilteredPackages()
    {
        var packages = (await packageService.GetPackagesByOwnerAsync()).ToList();
        return packages;
    }

    public List<GiteaPackage> FilterPackagesToDelete(List<GiteaPackage> packages)
    {
        var packagesToDelete = new List<GiteaPackage>();

        // Group packages by versioning variant
        var semanticVersionPackages = packages.Where(p => IsSemanticVersion(p.Version)).ToList();
        var dateVersionPackages = packages.Where(p => IsDateVersion(p.Version)).ToList();

        // Process each group with their respective variant logic
        packagesToDelete.AddRange(FilterPackagesToDeleteBySemanticVersion(semanticVersionPackages));
        packagesToDelete.AddRange(FilterPackagesToDeleteByDateVersion(dateVersionPackages));

        return packagesToDelete;
    }

    private List<GiteaPackage> FilterPackagesToDeleteBySemanticVersion(List<GiteaPackage> packages)
    {
        var packagesToDelete = new List<GiteaPackage>();

        // Group packages by release type
        // Note: Dev releases must be checked before prerelease since -dev is a suffix
        var devPackages = packages.Where(p => IsDevRelease(p.Version))
            .OrderByDescending(p => ParseSemanticVersion(p.Version))
            .ThenByDescending(p => p.CreatedAt)
            .ToList();
        var prereleasePackages = packages.Where(p => IsPrereleaseRelease(p.Version) && !IsDevRelease(p.Version))
            .OrderByDescending(p => ParseSemanticVersion(p.Version))
            .ThenByDescending(p => p.CreatedAt)
            .ToList();
        var prodPackages = packages.Where(p => IsProdRelease(p.Version))
            .OrderByDescending(p => ParseSemanticVersion(p.Version))
            .ThenByDescending(p => p.CreatedAt)
            .ToList();

        // Apply cleanup rules for each type
        packagesToDelete.AddRange(FilterProdReleases(prodPackages));
        packagesToDelete.AddRange(FilterPrereleaseReleases(prereleasePackages));
        packagesToDelete.AddRange(FilterDevReleases(devPackages));

        return packagesToDelete;
    }

    private List<GiteaPackage> FilterPackagesToDeleteByDateVersion(List<GiteaPackage> packages)
    {
        var packagesToDelete = new List<GiteaPackage>();

        // Group packages by release type
        // Note: Dev releases must be checked before prerelease since -dev is a suffix
        var devPackages = packages.Where(p => IsDevRelease(p.Version))
            .OrderByDescending(p => ParseDateVersion(p.Version))
            .ThenByDescending(p => p.CreatedAt)
            .ToList();
        var prereleasePackages = packages.Where(p => IsPrereleaseRelease(p.Version) && !IsDevRelease(p.Version))
            .OrderByDescending(p => ParseDateVersion(p.Version))
            .ThenByDescending(p => p.CreatedAt)
            .ToList();
        var prodPackages = packages.Where(p => IsProdRelease(p.Version))
            .OrderByDescending(p => ParseDateVersion(p.Version))
            .ThenByDescending(p => p.CreatedAt)
            .ToList();

        // Apply cleanup rules for each type
        packagesToDelete.AddRange(FilterProdReleasesDateVersion(prodPackages));
        packagesToDelete.AddRange(FilterPrereleaseReleasesDateVersion(prereleasePackages));
        packagesToDelete.AddRange(FilterDevReleasesDateVersion(devPackages));

        return packagesToDelete;
    }

    // Prod release methods for semantic versioning
    private List<GiteaPackage> FilterProdReleases(List<GiteaPackage> packages)
    {
        // Check if prod cleaning is enabled
        if (!GetBoolConfigValue("CLEAN_PROD_VERSIONS", false))
            return new List<GiteaPackage>();

        // Get keep count
        var keepCount = GetIntConfigValue("KEEP_PROD_VERSIONS", 5);

        // If keepCount <= 0, keep all
        if (keepCount <= 0)
            return new List<GiteaPackage>();

        // Packages are already sorted descending by version
        // Keep top N, delete rest
        return packages.Skip(keepCount).ToList();
    }

    // Prerelease methods for semantic versioning
    private List<GiteaPackage> FilterPrereleaseReleases(List<GiteaPackage> packages)
    {
        // Get keep count
        var keepCount = GetIntConfigValue("KEEP_PRERELEASE_VERSIONS", 3);

        // If keepCount <= 0, keep all
        if (keepCount <= 0)
            return new List<GiteaPackage>();

        // Packages are already sorted descending by version
        // Keep top N, delete rest
        return packages.Skip(keepCount).ToList();
    }

    // Dev release methods for semantic versioning
    private List<GiteaPackage> FilterDevReleases(List<GiteaPackage> packages)
    {
        // Get keep count
        var keepCount = GetIntConfigValue("KEEP_DEV_VERSIONS", 5);

        // If keepCount <= 0, keep all
        if (keepCount <= 0)
            return new List<GiteaPackage>();

        // Packages are already sorted descending by version
        // Keep top N, delete rest
        return packages.Skip(keepCount).ToList();
    }

    // Prod release methods for date-based versioning
    private List<GiteaPackage> FilterProdReleasesDateVersion(List<GiteaPackage> packages)
    {
        // Check if prod cleaning is enabled
        if (!GetBoolConfigValue("CLEAN_PROD_VERSIONS", false))
            return new List<GiteaPackage>();

        // Get keep count
        var keepCount = GetIntConfigValue("KEEP_PROD_VERSIONS", 5);

        // If keepCount <= 0, keep all
        if (keepCount <= 0)
            return new List<GiteaPackage>();

        // Packages are already sorted descending by version
        // Keep top N, delete rest
        return packages.Skip(keepCount).ToList();
    }

    // Prerelease methods for date-based versioning
    private List<GiteaPackage> FilterPrereleaseReleasesDateVersion(List<GiteaPackage> packages)
    {
        // Get keep count
        var keepCount = GetIntConfigValue("KEEP_PRERELEASE_VERSIONS", 3);

        // If keepCount <= 0, keep all
        if (keepCount <= 0)
            return new List<GiteaPackage>();

        // Packages are already sorted descending by version
        // Keep top N, delete rest
        return packages.Skip(keepCount).ToList();
    }

    // Dev release methods for date-based versioning
    private List<GiteaPackage> FilterDevReleasesDateVersion(List<GiteaPackage> packages)
    {
        // Get keep count
        var keepCount = GetIntConfigValue("KEEP_DEV_VERSIONS", 5);

        // If keepCount <= 0, keep all
        if (keepCount <= 0)
            return new List<GiteaPackage>();

        // Packages are already sorted descending by version
        // Keep top N, delete rest
        return packages.Skip(keepCount).ToList();
    }

    // Helper methods to identify release types
    private bool IsProdRelease(string version)
    {
        // Prod versions typically don't have pre-release identifiers (alpha, beta, rc, dev, etc.)
        return !version.Contains("-", StringComparison.OrdinalIgnoreCase);
    }

    private bool IsPrereleaseRelease(string version)
    {
        // Prerelease versions contain identifiers like -alpha, -beta, -rc, -preview
        // But NOT -dev, which is a separate release type
        var lowerVersion = version.ToLowerInvariant();
        return (lowerVersion.Contains("alpha") || lowerVersion.Contains("beta") ||
                lowerVersion.Contains("rc") || lowerVersion.Contains("preview")) ||
               lowerVersion.Contains("staging") && !lowerVersion.Contains("dev");
    }

    private bool IsDevRelease(string version)
    {
        // Dev versions contain identifiers like dev or similar
        return version.ToLowerInvariant().Contains("dev");
    }

    // Helper methods to identify versioning variant
    private bool IsSemanticVersion(string version)
    {
        // Semantic versioning: major.minor.micro.build with typically smaller numbers
        // Examples: 1.2.3.4, 2.0.1.100
        var versionPart = version.Split('-')[0];
        var parts = versionPart.Split('.').Where(p => !string.IsNullOrEmpty(p)).ToArray();

        if (parts.Length < 2 || parts.Length > 4)
            return false;

        // Try to parse all parts as numbers
        if (!parts.All(p => int.TryParse(p, out var num)))
            return false;

        // Semantic versioning typically has smaller major version numbers (0-20 range)
        if (int.TryParse(parts[0], out var major) && major > 100)
            return false; // Likely a date version if first number > 100

        return true;
    }

    private bool IsDateVersion(string version)
    {
        // Date-based versioning: year.month.day.build
        // Examples: 2024.12.25.1, 2025.2.14.100
        var versionPart = version.Split('-')[0];
        var parts = versionPart.Split('.').Where(p => !string.IsNullOrEmpty(p)).ToArray();

        if (parts.Length != 4)
            return false;

        // Try to parse all parts as numbers
        if (!parts.All(p => int.TryParse(p, out var num)))
            return false;

        // Date version should have year > 1000 and < 3000
        if (!int.TryParse(parts[0], out var year) || year < 1000 || year > 3000)
            return false;

        // Month should be 1-12
        if (!int.TryParse(parts[1], out var month) || month < 1 || month > 12)
            return false;

        // Day should be 1-31
        if (!int.TryParse(parts[2], out var day) || day < 1 || day > 31)
            return false;

        return true;
    }

    // Version parsing methods
    private (int major, int minor, int micro, int build) ParseSemanticVersion(string version)
    {
        // Remove suffix if present (e.g., "-alpha", "-dev")
        var versionPart = version.Split('-')[0];
        var parts = versionPart.Split('.').Select(p => int.TryParse(p, out var num) ? num : 0).ToArray();

        return (
            parts.Length > 0 ? parts[0] : 0,
            parts.Length > 1 ? parts[1] : 0,
            parts.Length > 2 ? parts[2] : 0,
            parts.Length > 3 ? parts[3] : 0
        );
    }

    private (int year, int month, int day, int build) ParseDateVersion(string version)
    {
        // Remove suffix if present (e.g., "-alpha", "-dev")
        var versionPart = version.Split('-')[0];
        var parts = versionPart.Split('.').Select(p => int.TryParse(p, out var num) ? num : 0).ToArray();

        return (
            parts.Length > 0 ? parts[0] : 0,
            parts.Length > 1 ? parts[1] : 0,
            parts.Length > 2 ? parts[2] : 0,
            parts.Length > 3 ? parts[3] : 0
        );
    }

    // Configuration helper methods
    private int GetIntConfigValue(string key, int defaultValue)
    {
        var value = configuration[key];
        if (string.IsNullOrEmpty(value))
            return defaultValue;

        if (int.TryParse(value, out var result))
            return result;

        return defaultValue;
    }

    private bool GetBoolConfigValue(string key, bool defaultValue)
    {
        var value = configuration[key];
        if (string.IsNullOrEmpty(value))
            return defaultValue;

        if (bool.TryParse(value, out var result))
            return result;

        // Handle common string representations
        if (value.Equals("true", StringComparison.OrdinalIgnoreCase) ||
            value.Equals("1", StringComparison.OrdinalIgnoreCase))
            return true;

        return defaultValue;
    }
}