// client/src/input/keymap.rs

use evdev::KeyCode;

/// Return Some(usage) if we have a known mapping from evdev::KeyCode -> HID usage code
pub fn keycode_to_usage(key: KeyCode) -> Option<u8> {
    match key {
        // --- Letters ------------------------------------------------------
        KeyCode::KEY_A => Some(0x04),
        KeyCode::KEY_B => Some(0x05),
        KeyCode::KEY_C => Some(0x06),
        KeyCode::KEY_D => Some(0x07),
        KeyCode::KEY_E => Some(0x08),
        KeyCode::KEY_F => Some(0x09),
        KeyCode::KEY_G => Some(0x0A),
        KeyCode::KEY_H => Some(0x0B),
        KeyCode::KEY_I => Some(0x0C),
        KeyCode::KEY_J => Some(0x0D),
        KeyCode::KEY_K => Some(0x0E),
        KeyCode::KEY_L => Some(0x0F),
        KeyCode::KEY_M => Some(0x10),
        KeyCode::KEY_N => Some(0x11),
        KeyCode::KEY_O => Some(0x12),
        KeyCode::KEY_P => Some(0x13),
        KeyCode::KEY_Q => Some(0x14),
        KeyCode::KEY_R => Some(0x15),
        KeyCode::KEY_S => Some(0x16),
        KeyCode::KEY_T => Some(0x17),
        KeyCode::KEY_U => Some(0x18),
        KeyCode::KEY_V => Some(0x19),
        KeyCode::KEY_W => Some(0x1A),
        KeyCode::KEY_X => Some(0x1B),
        KeyCode::KEY_Y => Some(0x1C),
        KeyCode::KEY_Z => Some(0x1D),

        // --- Number row ---------------------------------------------------
        KeyCode::KEY_1 => Some(0x1E),
        KeyCode::KEY_2 => Some(0x1F),
        KeyCode::KEY_3 => Some(0x20),
        KeyCode::KEY_4 => Some(0x21),
        KeyCode::KEY_5 => Some(0x22),
        KeyCode::KEY_6 => Some(0x23),
        KeyCode::KEY_7 => Some(0x24),
        KeyCode::KEY_8 => Some(0x25),
        KeyCode::KEY_9 => Some(0x26),
        KeyCode::KEY_0 => Some(0x27),

        // --- Common punctuation -------------------------------------------
        KeyCode::KEY_ENTER => Some(0x28),
        KeyCode::KEY_ESC => Some(0x29),
        KeyCode::KEY_BACKSPACE => Some(0x2A),
        KeyCode::KEY_TAB => Some(0x2B),
        KeyCode::KEY_SPACE => Some(0x2C),
        KeyCode::KEY_MINUS => Some(0x2D),
        KeyCode::KEY_EQUAL => Some(0x2E),
        KeyCode::KEY_LEFTBRACE => Some(0x2F),
        KeyCode::KEY_RIGHTBRACE => Some(0x30),
        KeyCode::KEY_BACKSLASH => Some(0x31),
        KeyCode::KEY_SEMICOLON => Some(0x33),
        KeyCode::KEY_APOSTROPHE => Some(0x34),
        KeyCode::KEY_GRAVE => Some(0x35),
        KeyCode::KEY_COMMA => Some(0x36),
        KeyCode::KEY_DOT => Some(0x37),
        KeyCode::KEY_SLASH => Some(0x38),

        // --- Function keys ------------------------------------------------
        KeyCode::KEY_CAPSLOCK => Some(0x39),
        KeyCode::KEY_F1 => Some(0x3A),
        KeyCode::KEY_F2 => Some(0x3B),
        KeyCode::KEY_F3 => Some(0x3C),
        KeyCode::KEY_F4 => Some(0x3D),
        KeyCode::KEY_F5 => Some(0x3E),
        KeyCode::KEY_F6 => Some(0x3F),
        KeyCode::KEY_F7 => Some(0x40),
        KeyCode::KEY_F8 => Some(0x41),
        KeyCode::KEY_F9 => Some(0x42),
        KeyCode::KEY_F10 => Some(0x43),
        KeyCode::KEY_F11 => Some(0x44),
        KeyCode::KEY_F12 => Some(0x45),
      
        // --- Navigation / editing cluster ---------------------------------
        KeyCode::KEY_SYSRQ        => Some(0x46),   // Print‑Screen
        KeyCode::KEY_SCROLLLOCK   => Some(0x47),
        KeyCode::KEY_PAUSE        => Some(0x48),
        KeyCode::KEY_INSERT       => Some(0x49),
        KeyCode::KEY_HOME         => Some(0x4A),
        KeyCode::KEY_PAGEUP       => Some(0x4B),
        KeyCode::KEY_DELETE       => Some(0x4C),
        KeyCode::KEY_END          => Some(0x4D),
        KeyCode::KEY_PAGEDOWN     => Some(0x4E),
        KeyCode::KEY_RIGHT        => Some(0x4F),
        KeyCode::KEY_LEFT         => Some(0x50),
        KeyCode::KEY_DOWN         => Some(0x51),
        KeyCode::KEY_UP           => Some(0x52),

        // --- Keypad / Num‑lock block --------------------------------------
        KeyCode::KEY_NUMLOCK      => Some(0x53),
        KeyCode::KEY_KPSLASH      => Some(0x54),
        KeyCode::KEY_KPASTERISK   => Some(0x55),
        KeyCode::KEY_KPMINUS      => Some(0x56),
        KeyCode::KEY_KPPLUS       => Some(0x57),
        KeyCode::KEY_KPENTER      => Some(0x58),
        KeyCode::KEY_KP1          => Some(0x59),
        KeyCode::KEY_KP2          => Some(0x5A),
        KeyCode::KEY_KP3          => Some(0x5B),
        KeyCode::KEY_KP4          => Some(0x5C),
        KeyCode::KEY_KP5          => Some(0x5D),
        KeyCode::KEY_KP6          => Some(0x5E),
        KeyCode::KEY_KP7          => Some(0x5F),
        KeyCode::KEY_KP8          => Some(0x60),
        KeyCode::KEY_KP9          => Some(0x61),
        KeyCode::KEY_KP0          => Some(0x62),
        KeyCode::KEY_KPDOT        => Some(0x63),
        KeyCode::KEY_KPEQUAL      => Some(0x67),

        // --- Misc ---------------------------------------------------------
        KeyCode::KEY_102ND        => Some(0x64),   // “<>” on ISO boards
        KeyCode::KEY_MENU         => Some(0x65),   // Application / Compose
        
        // We'll handle modifiers (ctrl, shift, alt, meta) in `is_modifier()`
        _ => None,
    }
}

/// If a key is a modifier, return the bit(s) to set in HID byte[0].
pub fn is_modifier(key: KeyCode) -> Option<u8> {
    match key {
        KeyCode::KEY_LEFTCTRL  => Some(0x01),
        KeyCode::KEY_LEFTSHIFT => Some(0x02),
        KeyCode::KEY_LEFTALT   => Some(0x04),
        KeyCode::KEY_LEFTMETA  => Some(0x08),
        KeyCode::KEY_RIGHTCTRL => Some(0x10),
        KeyCode::KEY_RIGHTSHIFT => Some(0x20),
        KeyCode::KEY_RIGHTALT  => Some(0x40),
        KeyCode::KEY_RIGHTMETA => Some(0x80),
        _ => None,
    }
}