const std = @import("std");
const rats = @import("rats");

const version = "0.0.0"; // TODO: pull this from build.zig.zon

pub fn main() !void {
    var gpa: std.heap.DebugAllocator(.{}) = .init;
    defer std.debug.assert(gpa.deinit() == .ok);
    const allocator = gpa.allocator();

    var file_path: ?[]const u8 = null;

    { // argument parsing
        var args = try std.process.argsWithAllocator(allocator);
        defer args.deinit();
        _ = args.next(); // Discargd argv[0];

        while (args.next()) |arg| {
            const eql = std.mem.eql;
            if (file_path != null) {
                std.debug.print("Ignoring argument after file path: {s}\n", .{arg});
            } else if (eql(u8, arg, "-h") or eql(u8, arg, "--help")) {
                std.debug.print(
                    \\Usage: rats [options] [file]
                    \\
                    \\Options:
                    \\  -h, --help      Display this help and exit.
                    \\  -v, --version   Display version information and exit.
                    \\
                , .{});
                return;
            } else if (eql(u8, arg, "-v") or eql(u8, arg, "--version")) {
                std.debug.print("rats v{s}\n", .{version});
                return;
            } else {
                file_path = arg;
            }
        }
    } // end argument parsing

    const use_stdin = (file_path == null) or std.mem.eql(u8, file_path.?, "-");

    std.debug.print(
        \\File path:  {?s}
        \\Stdin mode: {}
        \\
    , .{ file_path, use_stdin });

    // TODO: actually parse and run the file, or do a repl on stdin.
}