const std = @import("std");
var stdout_buffer: [1024]u8 = undefined;
var stdout_writer = std.fs.File.stdout().writer(&stdout_buffer);
const stdout = &stdout_writer.interface;

pub fn main() !void {
    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
    defer _ = gpa.deinit();
    const allocator = gpa.allocator();

    const args = try std.process.argsAlloc(allocator);
    defer std.process.argsFree(allocator, args);

    if (args.len < 3) {
        std.debug.print("Usage: {s} <database_file_path> <command>\n", .{args[0]});
        std.process.exit(1);
    }

    const database_file_path: []const u8 = args[1];
    const command: []const u8 = args[2];

    if (std.mem.eql(u8, command, ".dbinfo")) {
        var file = try std.fs.cwd().openFile(database_file_path, .{});
        defer file.close();

        var buf: [2]u8 = undefined;
        _ = try file.seekTo(16);
        _ = try file.read(&buf);
        const page_size = std.mem.readInt(u16, &buf, .big);
        try stdout.print("database page size: {}\n", .{page_size});

        _ = try file.seekTo(103);
        _ = try file.read(&buf);
        const num_tables = std.mem.readInt(u16, &buf, .big);
        try stdout.print("number of tables: {}\n", .{num_tables});
        try stdout.flush();
    }
}