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();
    try term.clearScreen();

    var box = Terminal.Box.init(allocator);
    defer box.deinit();
    box.content = "hi";
    box.border = true;

    try term.box.addChild(&box);
    term.box.border = true;

    try term.draw();

    // var box = Terminal.Box{
    //     .x = 0,
    //     .y = 0,
    //     .width = 13,
    //     .height = 1,

    //     .content = "hello world",
    //     .border = true,
    // };
    // try box.draw(&term);

    // try term.clearScreen();
    // try term.print("fooboo", .{});
    // try term.cursorLeft();
    // try term.cursorLeft();
    // try term.print("ar", .{});
    // // try term.cursorSet(12, 3);
    // try term.blinkOn();
    // try term.boldOn();
    // try term.underlineOn();
    // try term.italicsOn();
    // try term.print("ABCDEFGHIJKLMNOPQRSTUVWXYZ", .{});
    // try term.blinkOff();
    // try term.boldOff();
    // try term.underlineOff();
    // try term.italicsOff();
    // try term.print("eeheeveehee\n", .{});
}

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

    box: Box,

    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,
            .box = Box.init(allocator),
        };
        errdefer term.tty.close();
        errdefer term.info.deinit();
        term.uncook();
        return term;
    }

    pub fn deinit(self: *Terminal) void {
        self.box.deinit();
        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 draw(self: *Terminal) !void {
        try self.box.draw(self);
    }

    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 cursorUp(self: *Terminal) !void {
        try self.info.writeString(.cursor_up, self.tty.writer(), &[_]u32{});
    }

    pub fn cursorDown(self: *Terminal) !void {
        try self.info.writeString(.cursor_down, self.tty.writer(), &[_]u32{});
    }

    pub fn cursorLeft(self: *Terminal) !void {
        try self.info.writeString(.cursor_left, self.tty.writer(), &[_]u32{});
    }

    pub fn cursorRight(self: *Terminal) !void {
        try self.info.writeString(.cursor_right, self.tty.writer(), &[_]u32{});
    }

    pub fn cursorSet(self: *Terminal, x: u32, y: u32) !void {
        try self.info.writeString(.cursor_address, self.tty.writer(), &[_]u32{ y, x });
    }

    pub fn blinkOn(self: *Terminal) !void {
        try self.info.writeString(.enter_blink_mode, self.tty.writer(), &[_]u32{});
    }

    pub fn blinkOff(self: *Terminal) !void {
        try self.info.writeString(.exit_blink_mode, self.tty.writer(), &[_]u32{});
    }

    pub fn boldOn(self: *Terminal) !void {
        try self.info.writeString(.enter_bold_mode, self.tty.writer(), &[_]u32{});
    }

    pub fn boldOff(self: *Terminal) !void {
        try self.info.writeString(.exit_bold_mode, self.tty.writer(), &[_]u32{});
    }

    pub fn italicsOn(self: *Terminal) !void {
        try self.info.writeString(.enter_italics_mode, self.tty.writer(), &[_]u32{});
    }

    pub fn italicsOff(self: *Terminal) !void {
        try self.info.writeString(.exit_italics_mode, self.tty.writer(), &[_]u32{});
    }

    pub fn underlineOn(self: *Terminal) !void {
        try self.info.writeString(.enter_underline_mode, self.tty.writer(), &[_]u32{});
    }

    pub fn underlineOff(self: *Terminal) !void {
        try self.info.writeString(.exit_underline_mode, self.tty.writer(), &[_]u32{});
    }

    pub fn clearScreen(self: *Terminal) !void {
        try self.info.writeString(.clear_screen, self.tty.writer(), &[_]u32{});
    }

    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,
    };

    pub const Box = struct {
        parent: ?*Box,
        children: std.ArrayList(*Box),

        // x: u32,
        // y: u32,
        // width: u32,
        // height: u32,

        left: u32,
        right: u32,
        top: u32,
        bottom: u32,

        border_type: enum { line, bg } = .line,
        border_char: u8 = ' ',
        border_bg: i16 = -1,
        border_fg: i16 = -1,

        content: []const u8 = "",
        border: bool = false,

        pub fn init(allocator: mem.Allocator) Box {
            return .{
                .parent = null,
                .children = std.ArrayList(*Box).init(allocator),
                .x = 0,
                .y = 0,
                .width = 20,
                .height = 8,
            };
        }

        pub fn deinit(self: *Box) void {
            for (self.children.items) |child| child.deinit();
            self.children.deinit();
        }

        pub fn draw(self: *Box, term: *Terminal) !void {
            var x: u32 = 0;
            var y: u32 = 0;
            try term.cursorSet(self.x, self.y);

            switch (self.border_type) {
                .line => {
                    try term.print("", .{});
                    while (x < self.width) : (x += 1) try term.print("", .{});
                    try term.print("", .{});

                    y += 1;
                    while (y <= self.height) : (y += 1) {
                        try term.cursorSet(self.x, self.y + y);
                        try term.print("", .{});
                        try term.cursorSet(self.x + self.width + 1, self.y + y);
                        try term.print("", .{});
                    }

                    try term.cursorSet(self.x, self.y + y);
                },
                .bg => {},
            }

            // if (self.border) {
            //     try term.print("┌", .{});
            //     // x += 1;
            //     while (x < self.width) : (x += 1) try term.print("─", .{});
            //     try term.print("┐", .{});
            //     // x += 1;
            //     y += 1;
            //     while (y <= self.height) : (y += 1) {
            //         try term.cursorSet(self.x, self.y + y);
            //         try term.print("│", .{});
            //         try term.cursorSet(self.x + self.width + 1, self.y + y);
            //         try term.print("│", .{});
            //     }
            //     x = 0;
            //     try term.cursorSet(self.x + x, self.y + y);
            //     try term.print("└", .{});
            //     while (x < self.width) : (x += 1) try term.print("─", .{});
            //     try term.print("┘", .{});
            // }

            // x = self.x + 2;
            // y = self.y + 1;
            // try term.cursorSet(x, y);
            // if (self.content.len < self.width) {
            //     try term.print("{s}", .{self.content});
            //     x += @intCast(self.content.len);
            // } else {
            //     const space = mem.indexOfScalar(u8, self.content, ' ');
            //     if (space) |sp| {
            //         try term.print("{s}", .{self.content[0..sp]});
            //         y += 1;
            //         try term.cursorSet(x, y);
            //         try term.print("{s}", .{self.content[sp + 1 ..]});
            //     }
            // }

            for (self.children.items) |child| try child.draw(term);

            try term.cursorSet(self.x + self.width + 2, self.y + self.height + 1);
        }

        pub fn addChild(self: *Box, child: *Box) !void {
            std.debug.assert(child.parent == null);
            child.parent = self;
            child.x = self.x + 2;
            child.y = self.y + 2;
            child.width = self.width - 4;
            child.height = self.height - 4;
            try self.children.append(child);
        }
    };
};