#include "circularbuffer.hpp"
#include "idt.hpp"
#include "keyboard.hpp"
#include "portio.hpp"
#include "vgaterminal.hpp"

#include <array>
#include <cstdint>

extern TextOutput& term;

static CircularBuffer<char> keyboardBuffer;
static Port<0x60> keyboardPort;

static const std::array<char, 0x59> ScanCodeSet1 {{
    0, K_ESCAPE,
    '1', '2', '3', '4', '5', '6', '7', '8', '9', '0',
    '-', '=', '\b', '\t',
    'Q', 'W', 'E', 'R', 'T', 'Y', 'U', 'I', 'O', 'P', '[', ']', '\n', K_CONTROL_L,
    'A', 'S', 'D', 'F', 'G', 'H', 'J', 'K', 'L', ';', '\'', '`', K_SHIFT_L, '\\',
    'Z', 'X', 'C', 'V', 'B', 'N', 'M', ',', '.', '/',
    K_SHIFT_R, '*', K_ALT_L, ' ', K_CAPS,
    K_F1, K_F2, K_F3, K_F4, K_F5, K_F6, K_F7, K_F8, K_F9, K_F10,
    K_NUM, K_SCROLL, '7', '8', '9', '-', '4', '5', '6', '+', '1', '2', '3', '0', '.',
    0, 0, 0, // non-existant
    K_F11, K_F12
}};

static constexpr bool isReleased(auto ch) {
    return ch & 0x80;
}

static constexpr auto keycode(auto ch) {
    return ch & 0x7F;
}

void keyboard_initialize()
{
    keyboardBuffer = CircularBuffer<char>(128);

    idt_register_callback(33, [](auto& regs) {
        const std::uint8_t kc = keyboardPort;

        if (!isReleased(kc)) {
            const auto ch = ScanCodeSet1[keycode(kc)];
            //if (ch > 0)
            //    term.write(ch);

            keyboardBuffer.push_back(ch);
        }
    });
}

std::optional<char> keyboard_read()
{
    if (keyboardBuffer.empty()) {
        return {};
    } else {
        const auto ch = keyboardBuffer.front();
        keyboardBuffer.pop_front();
        return ch;
    }
}