use super::{
    DecodeState, Error, KeyCode, KeyEvent, KeyState, ScancodeSet, EXTENDED_KEY_CODE,
    KEY_RELEASE_CODE,
};

/// Contains the implementation of Scancode Set 1.
/// See the OS dev wiki: https://wiki.osdev.org/PS/2_Keyboard#Scan_Code_Set_1
pub struct ScancodeSet1;

impl ScancodeSet for ScancodeSet1 {
    /// Implements state logic for scancode set 1
    ///
    /// Start:
    /// E0 => Extended
    /// >= 0x80 => Key Up
    /// <= 0x7F => Key Down
    ///
    /// Extended:
    /// >= 0x80 => Extended Key Up
    /// <= 0x7F => Extended Key Down
    fn advance_state(state: &mut DecodeState, code: u8) -> Result<Option<KeyEvent>, Error> {
        match *state {
            DecodeState::Start => {
                match code {
                    EXTENDED_KEY_CODE => {
                        *state = DecodeState::Extended;
                        Ok(None)
                    }
                    0x80..=0xFF => {
                        // Release codes
                        Ok(Some(KeyEvent::new(
                            Self::map_scancode(code - 0x80)?,
                            KeyState::Up,
                        )))
                    }
                    _ => {
                        // Normal codes
                        Ok(Some(KeyEvent::new(
                            Self::map_scancode(code)?,
                            KeyState::Down,
                        )))
                    }
                }
            }
            DecodeState::Extended => {
                *state = DecodeState::Start;
                match code {
                    0x80..=0xFF => {
                        // Extended Release codes
                        Ok(Some(KeyEvent::new(
                            Self::map_extended_scancode(code - 0x80)?,
                            KeyState::Up,
                        )))
                    }
                    _ => {
                        // Normal release codes
                        Ok(Some(KeyEvent::new(
                            Self::map_extended_scancode(code)?,
                            KeyState::Down,
                        )))
                    }
                }
            }
            _ => {
                // Can't get in to this state
                unimplemented!();
            }
        }
    }

    /// Implements the single byte codes for Set 1.
    fn map_scancode(code: u8) -> Result<KeyCode, Error> {
        match code {
            0x01 => Ok(KeyCode::Escape),             // 01
            0x02 => Ok(KeyCode::Key1),               // 02
            0x03 => Ok(KeyCode::Key2),               // 03
            0x04 => Ok(KeyCode::Key3),               // 04
            0x05 => Ok(KeyCode::Key4),               // 05
            0x06 => Ok(KeyCode::Key5),               // 06
            0x07 => Ok(KeyCode::Key6),               // 07
            0x08 => Ok(KeyCode::Key7),               // 08
            0x09 => Ok(KeyCode::Key8),               // 09
            0x0A => Ok(KeyCode::Key9),               // 0A
            0x0B => Ok(KeyCode::Key0),               // 0B
            0x0C => Ok(KeyCode::Minus),              // 0C
            0x0D => Ok(KeyCode::Equals),             // 0D
            0x0E => Ok(KeyCode::Backspace),          // 0E
            0x0F => Ok(KeyCode::Tab),                // 0F
            0x10 => Ok(KeyCode::Q),                  // 10
            0x11 => Ok(KeyCode::W),                  // 11
            0x12 => Ok(KeyCode::E),                  // 12
            0x13 => Ok(KeyCode::R),                  // 13
            0x14 => Ok(KeyCode::T),                  // 14
            0x15 => Ok(KeyCode::Y),                  // 15
            0x16 => Ok(KeyCode::U),                  // 16
            0x17 => Ok(KeyCode::I),                  // 17
            0x18 => Ok(KeyCode::O),                  // 18
            0x19 => Ok(KeyCode::P),                  // 19
            0x1A => Ok(KeyCode::BracketSquareLeft),  // 1A
            0x1B => Ok(KeyCode::BracketSquareRight), // 1B
            0x1C => Ok(KeyCode::Enter),              // 1C
            0x1D => Ok(KeyCode::ControlLeft),        // 1D
            0x1E => Ok(KeyCode::A),                  // 1E
            0x1F => Ok(KeyCode::S),                  // 1F
            0x20 => Ok(KeyCode::D),                  // 20
            0x21 => Ok(KeyCode::F),                  // 21
            0x22 => Ok(KeyCode::G),                  // 22
            0x23 => Ok(KeyCode::H),                  // 23
            0x24 => Ok(KeyCode::J),                  // 24
            0x25 => Ok(KeyCode::K),                  // 25
            0x26 => Ok(KeyCode::L),                  // 26
            0x27 => Ok(KeyCode::SemiColon),          // 27
            0x28 => Ok(KeyCode::Quote),              // 28
            0x29 => Ok(KeyCode::BackTick),           // 29
            0x2A => Ok(KeyCode::ShiftLeft),          // 2A
            0x2B => Ok(KeyCode::BackSlash),          // 2B
            0x2C => Ok(KeyCode::Z),                  // 2C
            0x2D => Ok(KeyCode::X),                  // 2D
            0x2E => Ok(KeyCode::C),                  // 2E
            0x2F => Ok(KeyCode::V),                  // 2F
            0x30 => Ok(KeyCode::B),                  // 30
            0x31 => Ok(KeyCode::N),                  // 31
            0x32 => Ok(KeyCode::M),                  // 32
            0x33 => Ok(KeyCode::Comma),              // 33
            0x34 => Ok(KeyCode::Fullstop),           // 34
            0x35 => Ok(KeyCode::Slash),              // 35
            0x36 => Ok(KeyCode::ShiftRight),         // 36
            0x37 => Ok(KeyCode::NumpadStar),         // 37
            0x38 => Ok(KeyCode::AltLeft),            // 38
            0x39 => Ok(KeyCode::Spacebar),           // 39
            0x3A => Ok(KeyCode::CapsLock),           // 3A
            0x3B => Ok(KeyCode::F1),                 // 3B
            0x3C => Ok(KeyCode::F2),                 // 3C
            0x3D => Ok(KeyCode::F3),                 // 3D
            0x3E => Ok(KeyCode::F4),                 // 3E
            0x3F => Ok(KeyCode::F5),                 // 3F
            0x40 => Ok(KeyCode::F6),                 // 40
            0x41 => Ok(KeyCode::F7),                 // 41
            0x42 => Ok(KeyCode::F8),                 // 42
            0x43 => Ok(KeyCode::F9),                 // 43
            0x44 => Ok(KeyCode::F10),                // 44
            0x45 => Ok(KeyCode::NumpadLock),         // 45
            0x46 => Ok(KeyCode::ScrollLock),         // 46
            0x47 => Ok(KeyCode::Numpad7),            // 47
            0x48 => Ok(KeyCode::Numpad8),            // 48
            0x49 => Ok(KeyCode::Numpad9),            // 49
            0x4A => Ok(KeyCode::NumpadMinus),        // 4A
            0x4B => Ok(KeyCode::Numpad4),            // 4B
            0x4C => Ok(KeyCode::Numpad5),            // 4C
            0x4D => Ok(KeyCode::Numpad6),            // 4D
            0x4E => Ok(KeyCode::NumpadPlus),         // 4E
            0x4F => Ok(KeyCode::Numpad1),            // 4F
            0x50 => Ok(KeyCode::Numpad2),            // 50
            0x51 => Ok(KeyCode::Numpad3),            // 51
            0x52 => Ok(KeyCode::Numpad0),            // 52
            0x53 => Ok(KeyCode::NumpadPeriod),       // 53
            //0x54
            //0x55
            //0x56
            0x57 => Ok(KeyCode::F11), // 57
            0x58 => Ok(KeyCode::F12), // 58
            0x81..=0xD8 => Ok(Self::map_scancode(code - 0x80)?),
            _ => Err(Error::UnknownKeyCode),
        }
    }

    /// Implements the extended byte codes for set 1 (prefixed with E0)
    fn map_extended_scancode(code: u8) -> Result<KeyCode, Error> {
        match code {
            0x10 => Ok(KeyCode::PrevTrack), // E010
            //0x11
            //0x12
            //0x13
            //0x14
            //0x15
            //0x16
            //0x17
            //0x18
            0x19 => Ok(KeyCode::NextTrack), // E019
            //0x1A
            //0x1B
            0x1C => Ok(KeyCode::NumpadEnter),  // E01C
            0x1D => Ok(KeyCode::ControlRight), // E01D
            //0x1E
            //0x1F
            0x20 => Ok(KeyCode::Mute),       // E020
            0x21 => Ok(KeyCode::Calculator), // E021
            0x22 => Ok(KeyCode::Play),       // E022
            //0x23
            0x24 => Ok(KeyCode::Stop), // E024
            //0x25
            //0x26
            //0x27
            //0x28
            //0x29
            //0x2A
            //0x2B
            //0x2C
            //0x2D
            0x2E => Ok(KeyCode::VolumeDown), // E02E
            //0x2F
            0x30 => Ok(KeyCode::VolumeUp), // E030
            //0x31
            0x32 => Ok(KeyCode::WWWHome), // E032
            //0x33
            //0x34
            0x35 => Ok(KeyCode::NumpadSlash), // E035
            //0x36
            //0x37
            0x38 => Ok(KeyCode::AltRight), // E038
            //0x39
            //0x3A
            //0x3B
            //0x3C
            //0x3D
            //0x3E
            //0x3F
            //0x40
            //0x41
            //0x42
            //0x43
            //0x44
            //0x45
            //0x46
            0x47 => Ok(KeyCode::Home),    // E047
            0x48 => Ok(KeyCode::ArrowUp), // E048
            0x49 => Ok(KeyCode::PageUp),  // E049
            //0x4A
            0x4B => Ok(KeyCode::ArrowLeft), // E04B
            //0x4C
            0x4D => Ok(KeyCode::ArrowRight), // E04D
            //0x4E
            0x4F => Ok(KeyCode::End),       // E04F
            0x50 => Ok(KeyCode::ArrowDown), // E050
            0x51 => Ok(KeyCode::PageDown),  // E051
            0x52 => Ok(KeyCode::Insert),    // E052
            0x53 => Ok(KeyCode::Delete),    // E053
            0x90..=0xED => Ok(Self::map_extended_scancode(code - 0x80)?),
            _ => Err(Error::UnknownKeyCode),
        }
    }
}

/// Contains the implementation of Scancode Set 2.
/// See the OS dev wiki: https://wiki.osdev.org/PS/2_Keyboard#Scan_Code_Set_2
pub struct ScancodeSet2;

impl ScancodeSet for ScancodeSet2 {
    /// Implements state logic for scancode set 2
    ///
    /// Start:
    /// F0 => Release
    /// E0 => Extended
    /// xx => Key Down
    ///
    /// Release:
    /// xxx => Key Up
    ///
    /// Extended:
    /// F0 => Release Extended
    /// xx => Extended Key Down
    ///
    /// Release Extended:
    /// xxx => Extended Key Up
    fn advance_state(state: &mut DecodeState, code: u8) -> Result<Option<KeyEvent>, Error> {
        match *state {
            DecodeState::Start => match code {
                EXTENDED_KEY_CODE => {
                    *state = DecodeState::Extended;
                    Ok(None)
                }
                KEY_RELEASE_CODE => {
                    *state = DecodeState::Release;
                    Ok(None)
                }
                _ => Ok(Some(KeyEvent::new(
                    Self::map_scancode(code)?,
                    KeyState::Down,
                ))),
            },
            DecodeState::Release => {
                *state = DecodeState::Start;
                Ok(Some(KeyEvent::new(Self::map_scancode(code)?, KeyState::Up)))
            }
            DecodeState::Extended => match code {
                KEY_RELEASE_CODE => {
                    *state = DecodeState::ExtendedRelease;
                    Ok(None)
                }
                _ => {
                    *state = DecodeState::Start;
                    Ok(Some(KeyEvent::new(
                        Self::map_extended_scancode(code)?,
                        KeyState::Down,
                    )))
                }
            },
            DecodeState::ExtendedRelease => {
                *state = DecodeState::Start;
                Ok(Some(KeyEvent::new(
                    Self::map_extended_scancode(code)?,
                    KeyState::Up,
                )))
            }
        }
    }

    /// Implements the single byte codes for Set 2.
    fn map_scancode(code: u8) -> Result<KeyCode, Error> {
        match code {
            0x01 => Ok(KeyCode::F9),                 // 01
            0x03 => Ok(KeyCode::F5),                 // 03
            0x04 => Ok(KeyCode::F3),                 // 04
            0x05 => Ok(KeyCode::F1),                 // 05
            0x06 => Ok(KeyCode::F2),                 // 06
            0x07 => Ok(KeyCode::F12),                // 07
            0x09 => Ok(KeyCode::F10),                // 09
            0x0A => Ok(KeyCode::F8),                 // 0A
            0x0B => Ok(KeyCode::F6),                 // 0B
            0x0C => Ok(KeyCode::F4),                 // 0C
            0x0D => Ok(KeyCode::Tab),                // 0D
            0x0E => Ok(KeyCode::BackTick),           // 0E
            0x11 => Ok(KeyCode::AltLeft),            // 11
            0x12 => Ok(KeyCode::ShiftLeft),          // 12
            0x14 => Ok(KeyCode::ControlLeft),        // 14
            0x15 => Ok(KeyCode::Q),                  // 15
            0x16 => Ok(KeyCode::Key1),               // 16
            0x1A => Ok(KeyCode::Z),                  // 1A
            0x1B => Ok(KeyCode::S),                  // 1B
            0x1C => Ok(KeyCode::A),                  // 1C
            0x1D => Ok(KeyCode::W),                  // 1D
            0x1e => Ok(KeyCode::Key2),               // 1e
            0x21 => Ok(KeyCode::C),                  // 21
            0x22 => Ok(KeyCode::X),                  // 22
            0x23 => Ok(KeyCode::D),                  // 23
            0x24 => Ok(KeyCode::E),                  // 24
            0x25 => Ok(KeyCode::Key4),               // 25
            0x26 => Ok(KeyCode::Key3),               // 26
            0x29 => Ok(KeyCode::Spacebar),           // 29
            0x2A => Ok(KeyCode::V),                  // 2A
            0x2B => Ok(KeyCode::F),                  // 2B
            0x2C => Ok(KeyCode::T),                  // 2C
            0x2D => Ok(KeyCode::R),                  // 2D
            0x2E => Ok(KeyCode::Key5),               // 2E
            0x31 => Ok(KeyCode::N),                  // 31
            0x32 => Ok(KeyCode::B),                  // 32
            0x33 => Ok(KeyCode::H),                  // 33
            0x34 => Ok(KeyCode::G),                  // 34
            0x35 => Ok(KeyCode::Y),                  // 35
            0x36 => Ok(KeyCode::Key6),               // 36
            0x3A => Ok(KeyCode::M),                  // 3A
            0x3B => Ok(KeyCode::J),                  // 3B
            0x3C => Ok(KeyCode::U),                  // 3C
            0x3D => Ok(KeyCode::Key7),               // 3D
            0x3E => Ok(KeyCode::Key8),               // 3E
            0x41 => Ok(KeyCode::Comma),              // 41
            0x42 => Ok(KeyCode::K),                  // 42
            0x43 => Ok(KeyCode::I),                  // 43
            0x44 => Ok(KeyCode::O),                  // 44
            0x45 => Ok(KeyCode::Key0),               // 45
            0x46 => Ok(KeyCode::Key9),               // 46
            0x49 => Ok(KeyCode::Fullstop),           // 49
            0x4A => Ok(KeyCode::Slash),              // 4A
            0x4B => Ok(KeyCode::L),                  // 4B
            0x4C => Ok(KeyCode::SemiColon),          // 4C
            0x4D => Ok(KeyCode::P),                  // 4D
            0x4E => Ok(KeyCode::Minus),              // 4E
            0x52 => Ok(KeyCode::Quote),              // 52
            0x54 => Ok(KeyCode::BracketSquareLeft),  // 54
            0x55 => Ok(KeyCode::Equals),             // 55
            0x58 => Ok(KeyCode::CapsLock),           // 58
            0x59 => Ok(KeyCode::ShiftRight),         // 59
            0x5A => Ok(KeyCode::Enter),              // 5A
            0x5B => Ok(KeyCode::BracketSquareRight), // 5B
            0x5D => Ok(KeyCode::HashTilde),          // 5D
            0x61 => Ok(KeyCode::BackSlash),          // 61
            0x66 => Ok(KeyCode::Backspace),          // 66
            0x69 => Ok(KeyCode::Numpad1),            // 69
            0x6B => Ok(KeyCode::Numpad4),            // 6B
            0x6C => Ok(KeyCode::Numpad7),            // 6C
            0x70 => Ok(KeyCode::Numpad0),            // 70
            0x71 => Ok(KeyCode::NumpadPeriod),       // 71
            0x72 => Ok(KeyCode::Numpad2),            // 72
            0x73 => Ok(KeyCode::Numpad5),            // 73
            0x74 => Ok(KeyCode::Numpad6),            // 74
            0x75 => Ok(KeyCode::Numpad8),            // 75
            0x76 => Ok(KeyCode::Escape),             // 76
            0x77 => Ok(KeyCode::NumpadLock),         // 77
            0x78 => Ok(KeyCode::F11),                // 78
            0x79 => Ok(KeyCode::NumpadPlus),         // 79
            0x7A => Ok(KeyCode::Numpad3),            // 7A
            0x7B => Ok(KeyCode::NumpadMinus),        // 7B
            0x7C => Ok(KeyCode::NumpadStar),         // 7C
            0x7D => Ok(KeyCode::Numpad9),            // 7D
            0x7E => Ok(KeyCode::ScrollLock),         // 7E
            0x83 => Ok(KeyCode::F7),                 // 83
            _ => Err(Error::UnknownKeyCode),
        }
    }

    /// Implements the extended byte codes for set 1 (prefixed with E0)
    fn map_extended_scancode(code: u8) -> Result<KeyCode, Error> {
        match code {
            0x11 => Ok(KeyCode::AltRight),     // E011
            0x14 => Ok(KeyCode::ControlRight), // E014
            0x1F => Ok(KeyCode::WindowsLeft),  // E01F
            0x27 => Ok(KeyCode::WindowsRight), // E027
            0x2F => Ok(KeyCode::Menus),        // E02F
            0x4A => Ok(KeyCode::NumpadSlash),  // E04A
            0x5A => Ok(KeyCode::NumpadEnter),  // E05A
            0x69 => Ok(KeyCode::End),          // E069
            0x6B => Ok(KeyCode::ArrowLeft),    // E06B
            0x6C => Ok(KeyCode::Home),         // E06C
            0x70 => Ok(KeyCode::Insert),       // E070
            0x71 => Ok(KeyCode::Delete),       // E071
            0x72 => Ok(KeyCode::ArrowDown),    // E072
            0x74 => Ok(KeyCode::ArrowRight),   // E074
            0x75 => Ok(KeyCode::ArrowUp),      // E075
            0x7A => Ok(KeyCode::PageDown),     // E07A
            0x7D => Ok(KeyCode::PageUp),       // E07D
            _ => Err(Error::UnknownKeyCode),
        }
    }
}