using Microsoft.AspNetCore.Http;

namespace ErsatzTV;

// Phase (a) of the Blazor -> ChicoryTV SPA cutover (ersatztv#91).
//
// The React SPA (served under /app) is now the default UI: the legacy Blazor
// routes below 302-redirect to their SPA equivalents. Only routes that already
// have SPA parity are listed here. Blazor pages WITHOUT a SPA equivalent are
// deliberately left reachable (no redirect) so their functionality stays
// available while the SPA catches up:
//   /system/health (Blazor home escape hatch; Index.razor also lives here),
//   /channels/{id} edit, /channels/numbers, /media/* (collections etc.),
//   /ffmpeg, /watermarks, /blocks, /decos, /templates, /deco-templates,
//   schedule/playout detail editors, /system/logs, /system/troubleshooting.
//
// Phase (b) removes the redirected Blazor pages entirely, but that is GATED on
// full SPA parity for every route in this map. Until then this map is the
// single source of truth for "what has migrated" and is expected to grow.
public static class LegacyUiRedirects
{
    // Blazor route -> SPA route. EXACT paths only (no prefix matching); a single
    // trailing slash on the request is normalized away before lookup.
    public static readonly IReadOnlyDictionary<string, string> Map =
        new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase)
        {
            ["/"] = "/app",
            ["/channels"] = "/app/channels",
            ["/channels/add"] = "/app/new-channel",
            ["/schedules"] = "/app/schedules",
            ["/playouts"] = "/app/playouts",
            ["/media/libraries"] = "/app/libraries",
            ["/settings/ffmpeg"] = "/app/settings/streaming",
            ["/settings/hdhr"] = "/app/settings/system",
            ["/settings/logging"] = "/app/settings/logging",
            ["/settings/playout"] = "/app/settings/playout",
            ["/settings/scanner"] = "/app/settings/scanner",
            ["/settings/ui"] = "/app/settings/general",
            ["/settings/xmltv"] = "/app/settings/xmltv"
        };

    public static bool TryGetRedirect(PathString path, out string target)
    {
        target = string.Empty;

        string value = path.Value;
        if (string.IsNullOrEmpty(value))
        {
            return false;
        }

        // Normalize a single trailing slash so "/channels/" matches "/channels"
        // (but keep root "/" intact). Guard against a path of all slashes (e.g.
        // "//") collapsing down to "/" and falsely matching the root entry.
        if (value.Length > 1 && value.EndsWith('/'))
        {
            string trimmed = value[..^1];
            if (trimmed == "/")
            {
                return false;
            }

            value = trimmed;
        }

        if (Map.TryGetValue(value, out string mapped))
        {
            target = mapped;
            return true;
        }

        return false;
    }
}