using CliWrap;
using InnovEnergy.Lib.Utils;
using static System.StringSplitOptions;
using static InnovEnergy.Server.FirmwareCiDaemon.ExitException;

namespace InnovEnergy.Server.FirmwareCiDaemon;

public static class Fossil
{
    public static String FossilFile { get; set; }
    public static String FossilUser { get; set; }

    // TODO: get commit/branch without checkout

    public static Commit Checkout(this Branch branch)
    {
        var fossilDir = Open();
        Update(fossilDir, branch, FossilUser);
        return new Commit(fossilDir);
    }

    public static CommitInfo GetLatestCommitInfo(this Branch branch)
    {
        using var fossilDir = Open();
        var (hash, comment) = Update(fossilDir, branch, FossilUser);
        return new CommitInfo { Hash = hash, Comment = comment, Branch = branch};
    }

    private static Disposable<String> Open()
    {
        var fossilDir = FileSystem.CreateTmpDir();
        var fossilCmd = Cli
            .Wrap("fossil")
            .WithWorkingDirectory(fossilDir);

        var open = fossilCmd
            .WithArguments($"open {FossilFile} --empty")
            .ExecuteSync();

        if (open.exitCode != 0)
        {
            fossilDir.Dispose();
            Exit("failed to open " + Path.GetFileName(FossilFile) + "\n" + open.stdOut + "\n" + open.stdErr);
        }

        return fossilDir.BeforeDisposeDo(Close);

        void Close() => fossilCmd.WithArguments("close").ExecuteSync();
    }

    public static (String hash, String comment) Update(String fossilDir, Branch branch, String fossilUser)
    {
        var fossil = Cli
            .Wrap("fossil")
            .WithArguments($"update --user {fossilUser} {branch.GetName()}")
            .WithWorkingDirectory(fossilDir)
            .WithValidation(CommandResultValidation.None)
            .ExecuteSync();

        if (fossil.exitCode != 0)
            Exit($"failed to update!\n{fossil.stdOut}");

        var fossilOutLines = fossil.stdOut.SplitLines();

        const String checkoutPrefix = "updated-to:";
        const String commentPrefix  = "comment:";

        var hash = fossilOutLines
            .Single(l => l.StartsWith(checkoutPrefix))
            .Split(" ", RemoveEmptyEntries)
            .ElementAt(1);

        var comment = fossilOutLines
            .Single(l => l.StartsWith(commentPrefix))
            .Substring(commentPrefix.Length)
            .SkipWhile(c => c == ' ')
            .TakeWhile(c => c != '(') // there is a (user: ig) at the end, stops at the first (, but whatever
            .Apply(String.Concat)
            .Trim();

        return (hash, comment);
    }
}