const std = @import("std");
const os = std.os;
const io = std.io;
const fs = std.fs;
const mem = std.mem;
const heap = std.heap;
const fmt = std.fmt;

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

    var term = try Terminal.init(allocator);
    defer term.deinit();

    // var info = try Terminal.Info.init(allocator);
    // defer info.deinit();

    // var seq = Terminal.Info.Sequence.init(allocator, &info);
    // defer seq.deinit();
    // try seq.cursorLeft();
    try term.print("poopoo", .{});
    try term.cursorLeft();
    try term.cursorLeft();
    try term.print("ee", .{});
    // try seq.writeOut(term.tty.writer()); //io.AnyWriter{ .context = &term.tty, .writeFn = &fs.File.write });
}

pub const Terminal = struct {
    tty: fs.File,
    original_termios: os.linux.termios,
    info: Info,
    allocator: mem.Allocator,

    pub fn init(allocator: mem.Allocator) !Terminal {
        var term = Terminal{
            .tty = try fs.openFileAbsolute("/dev/tty", .{ .mode = .read_write }),
            .original_termios = undefined,
            .info = try Info.init(allocator),
            .allocator = allocator,
        };
        errdefer term.tty.close();
        errdefer term.info.deinit();
        term.uncook();
        return term;
    }

    pub fn deinit(self: *Terminal) void {
        self.cook();
        self.tty.close();
        self.info.deinit();
    }

    // pub fn poll(self: *Terminal) void {}

    fn uncook(self: *Terminal) void {
        _ = os.linux.tcgetattr(self.tty.handle, &self.original_termios);
        var raw = self.original_termios;

        raw.lflag.ECHO = false;
        raw.lflag.ICANON = false;
        raw.lflag.ISIG = false;
        raw.lflag.IEXTEN = false;

        raw.iflag.IXON = false;
        raw.iflag.ICRNL = false;
        raw.iflag.BRKINT = false;
        raw.iflag.INPCK = false;
        raw.iflag.ISTRIP = false;

        raw.oflag.OPOST = false;

        raw.cc[@intFromEnum(os.linux.V.TIME)] = 0;
        raw.cc[@intFromEnum(os.linux.V.MIN)] = 1;

        _ = os.linux.tcsetattr(self.tty.handle, .FLUSH, &raw);
    }

    fn cook(self: *Terminal) void {
        _ = os.linux.tcsetattr(self.tty.handle, .FLUSH, &self.original_termios);
    }

    pub fn print(self: *Terminal, comptime format: []const u8, args: anytype) !void {
        const formatted = try fmt.allocPrint(self.allocator, format, args);
        defer self.allocator.free(formatted);
        try self.tty.writeAll(formatted);
    }

    pub fn cursorLeft(self: *Terminal) !void {
        try self.info.writeString(.cursor_left, self.tty.writer());
        // try self.info.cursorLeft(self.tty.writer());
    }

    pub const Info = @import("terminfo.zig");

    pub const SpecialKey = enum(u16) {
        home,
        end,
        page_up,
        page_down,
        delete,
        backspace,
        arrow_left,
        arrow_right,
        arrow_up,
        arrow_down,
    };
};