using PostFundManagement.Domain.Abstractions;
using PostFundManagement.Domain.Errors;
using PostFundManagement.Application.Extensions;

namespace PostFundManagement.Application.Services.Shared;

public sealed partial class HashService(IHashids hasher) : IService
{
    public static bool IsMd5Hash(string? value) =>
        !string.IsNullOrWhiteSpace(value) && Patterns.Md5Regex.IsMatch(value);

    public static bool IsSha256Hash(string? value) =>
        !string.IsNullOrWhiteSpace(value) && Patterns.Sha256Regex.IsMatch(value);

    public static string? StringToSha256Hash(string? input) =>
        string.IsNullOrEmpty(input) ? null : Convert.ToHexString(SHA256.HashData(Encoding.UTF8.GetBytes(input)));

    public static string? StreamToSha256Hash(Stream stream) =>
        stream is null ? null : Convert.ToHexString(SHA256.HashData(stream));

    public static string? BytesToSha256Hash(byte[] bytes) =>
        bytes is null ? null : Convert.ToHexString(SHA256.HashData(bytes));

    public static Result<string> ToMd5Hash(string input)
    {
        if (string.IsNullOrEmpty(input))
            return Result.Fail<string>(ValidationError.Create("Input content cannot be null or empty for MD5 processing."));

        byte[] bytes = MD5.HashData(Encoding.UTF8.GetBytes(input));

        return Result.Ok(Convert.ToHexString(bytes).ToLowerInvariant());
    }

    public Result<string> HashEncodeHex(string input) => 
        Result.FailIf(string.IsNullOrWhiteSpace(input) || !Patterns.HexHashRegex.IsMatch(input), 
            ValidationError.Create("Input must be a valid hexadecimal string."))
                    .ToResult(hasher.EncodeHex(input));

    public Result<string> HashEncodeIntId(int id) => 
        Result.FailIf(id < 0, ValidationError.Create("Id cannot be negative."))
            .ToResult(hasher.Encode(id));

    public Result<string> HashEncodeLongId(long id) => 
        Result.FailIf(id < 0, ValidationError.Create("Id cannot be negative."))
            .ToResult(hasher.EncodeLong(id));

    public Result<int> DecodeIntIdHash(string hash)
    {
        if (string.IsNullOrWhiteSpace(hash))
            return Result.Fail<int>(ValidationError.Create("Invalid token layout."));

        int[] decoded = hasher.Decode(hash);

        return Result.FailIf(decoded.Length <= 0, ValidationError.Create("Invalid or modified Int hash token."))
            .ToResult(decoded[0]);
    }

    public Result<long> DecodeLongIdHash(string hash)
    {
        if (string.IsNullOrWhiteSpace(hash))
            return Result.Fail<long>(ValidationError.Create("Invalid token layout."));

        long[] decoded = hasher.DecodeLong(hash);

        return Result.FailIf(decoded.Length <= 0, ValidationError.Create("Invalid or modified Long hash token."))
            .ToResult(decoded[0]);
    }

    public async Task<Result<string>> DecodeHexHash(string hex) =>
        await Result.Try((Func<Task<Result<string>>>)(async () =>
        {
            string decoded = hasher.DecodeHex(hex);

            return Result.FailIf(string.IsNullOrEmpty(decoded), ValidationError.Create("Invalid or corrupted hex hash."))
            .ToResult(decoded);
        }));
}