use clap::{Parser, Subcommand};
use gemma::chip8::computer_manager::Chip8ComputerManager;
use std::path::Path;
use std::time::Instant;
use std::{default::Default, path::PathBuf};
use support::ui_state::ROMPATH_DEFAULT;
use support::{emmagui_support::GemmaImguiSupport, ui_state::ImGuiUiState};

mod support;

/// Keypad Mappings for my Linux box
/// 1 2 3 C
/// 4 5 6 D
/// 7 8 9 E
/// A 0 B F

const LIN_KEYS: [(u16, u8); 0x10] = [
    (537, 0x01),
    (538, 0x02),
    (539, 0x03),
    (540, 0x0c),
    (562, 0x04),
    (568, 0x05),
    (550, 0x06),
    (563, 0x0d),
    (546, 0x7),
    (564, 0x8),
    (549, 0x9),
    (551, 0xe),
    (571, 0xa),
    (569, 0x0),
    (548, 0xb),
    (567, 0xf),
];

#[derive(Parser)]
#[command(version, about, long_about = None)]
struct GemmaImguiCLIOptions {
    roms_directory: Option<PathBuf>,
}

fn main() {
    pretty_env_logger::init();

    let cli_options = GemmaImguiCLIOptions::parse();

    let mut system = Chip8ComputerManager::default();
    println!("GOT A ROMS_DIRECTORY => [{:?}]", cli_options.roms_directory);
    println!("{:?}", std::env::var("PWD"));
    let mut ui_state = if cli_options.roms_directory.is_none() {
        ImGuiUiState::new(Some(PathBuf::from(ROMPATH_DEFAULT)))
    } else {
        ImGuiUiState::new(cli_options.roms_directory)
    };

    support::simple_init(file!(), move |_, ui| {
        let current_time = Instant::now();
        let mut num_cycles = 0;

        // Key Checks
        let down_keys = ui.io().keys_down;

        // START DEBUG CODE TO DISPLAY WHAT KEYS WE TRAPPED
        for (idx, val) in down_keys.iter().enumerate() {
            if *val {
                println!("{idx} = {val}");
            }
        }
        // END DEBUG CODE

        for (key_code, key_reg) in LIN_KEYS {
            if down_keys[key_code as usize] {
                system.press_key(key_reg);
                system.wait_for_instruction();
            } else {
                // do we need to release it?
                if system.is_key_pressed(key_reg) {
                    system.release_key(key_reg);
                }
            }
        }

        let target_ms = ui_state.frame_time;
        let loop_start_time = Instant::now();
        while Instant::now().duration_since(current_time).as_millis() < target_ms as u128
            && num_cycles < ui_state.target_ips
        {
            if system.tick() {
                num_cycles += 1;
            }
        }
        let cycles_time = Instant::now().duration_since(loop_start_time);
        if num_cycles > 0 {
            println!(
                "Ran for {}ms and executed {}/{} cycles.",
                cycles_time.as_millis(),
                num_cycles,
                ui_state.target_ips
            );
        }
        // GUI Parts
        if ui_state.show_video {
            GemmaImguiSupport::video_display(system.state(), &ui_state, ui);
        }

        GemmaImguiSupport::system_controls(&mut system, &mut ui_state, ui);

        if ui_state.show_registers {
            GemmaImguiSupport::registers_view(system.state(), ui);
        }

        if ui_state.show_memory {
            let active_instruction = system.state().registers.peek_pc();
            GemmaImguiSupport::hex_memory_display(
                system.state().memory.clone(),
                (0x100, 0x10),
                active_instruction as i16,
                ui,
            );
        }

        if ui_state.show_keypad {
            GemmaImguiSupport::keypad_display(system.state(), ui);
        }
    });
}