namespace Journal.WebGateway.Infrastructure;

public sealed record RepoRootResolution(string Root, bool IsCustom, string Source);

public static class PathResolver
{
    public static RepoRootResolution ResolveRepoRoot(IConfiguration config)
    {
        var fromConfig = config.GetValue<string>("GatewaySettings:RepoRoot");
        if (!string.IsNullOrWhiteSpace(fromConfig) && Directory.Exists(fromConfig))
            return new RepoRootResolution(Path.GetFullPath(fromConfig), true, "config");

        var fromEnv = Environment.GetEnvironmentVariable("JOURNAL_PROJECT_ROOT");
        if (!string.IsNullOrWhiteSpace(fromEnv) && Directory.Exists(fromEnv))
            return new RepoRootResolution(Path.GetFullPath(fromEnv), true, "env");

        if (IsPublishedLayout())
        {
            throw new InvalidOperationException(
                "Published WebGateway requires an explicit root. Set GatewaySettings:RepoRoot or JOURNAL_PROJECT_ROOT before launch.");
        }

        foreach (var start in new[] { Directory.GetCurrentDirectory(), AppContext.BaseDirectory })
        {
            var resolved = FindRepoRoot(start);
            if (resolved is not null)
                return new RepoRootResolution(resolved, false, "auto");
        }

        return new RepoRootResolution(Path.GetFullPath(Directory.GetCurrentDirectory()), false, "cwd");
    }

    private static string? FindRepoRoot(string start)
    {
        var cursor = Path.GetFullPath(start);
        while (!string.IsNullOrWhiteSpace(cursor))
        {
            if (File.Exists(Path.Combine(cursor, "Journal.slnx")) ||
                Directory.Exists(Path.Combine(cursor, "Journal.Sidecar")) ||
                File.Exists(Path.Combine(cursor, "Journal.Sidecar.exe")) ||
                File.Exists(Path.Combine(cursor, "Journal.Sidecar")) ||
                Directory.Exists(Path.Combine(cursor, "Journal.Core")))
                return cursor;

            var parent = Directory.GetParent(cursor);
            if (parent is null || string.Equals(parent.FullName, cursor, StringComparison.OrdinalIgnoreCase))
                return null;

            cursor = parent.FullName;
        }
        return null;
    }

    public static string ResolveWebDist(string repoRootPath, IConfiguration config)
    {
        var fromConfig = config.GetValue<string>("GatewaySettings:WebDist");
        if (!string.IsNullOrWhiteSpace(fromConfig)) return Path.GetFullPath(fromConfig);

        var fromEnv = Environment.GetEnvironmentVariable("JOURNAL_WEB_DIST");
        if (!string.IsNullOrWhiteSpace(fromEnv)) return Path.GetFullPath(fromEnv);

        var packagedWwwRoot = Path.Combine(AppContext.BaseDirectory, "wwwroot");
        if (Directory.Exists(packagedWwwRoot)) return packagedWwwRoot;

        return Path.Combine(repoRootPath, "Journal.App", "build");
    }

    private static bool IsPublishedLayout()
    {
        var baseDir = Path.GetFullPath(AppContext.BaseDirectory);
        return Directory.Exists(Path.Combine(baseDir, "wwwroot")) &&
               !File.Exists(Path.Combine(baseDir, "Journal.slnx")) &&
               !Directory.Exists(Path.Combine(baseDir, "Journal.WebGateway"));
    }
}