use uuid::Uuid;

pub const WAVE_TAG_PCM: u16 = 0x0001;
pub const WAVE_TAG_FLOAT: u16 = 0x0003;
pub const WAVE_TAG_MPEG: u16 = 0x0050;
pub const WAVE_TAG_EXTENDED: u16 = 0xFFFE;

/* RC 2361 §4:

 WAVE Format IDs are converted to GUIDs by inserting the hexadecimal
   value of the WAVE Format ID into the XXXXXXXX part of the following
   template: {XXXXXXXX-0000-0010-8000-00AA00389B71}. For example, a WAVE
   Format ID of 123 has the GUID value of {00000123-0000-0010-8000-
   00AA00389B71}.

*/

pub const WAVE_UUID_PCM: Uuid = Uuid::from_bytes([
    0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00, 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71,
]);

pub const WAVE_UUID_FLOAT: Uuid = Uuid::from_bytes([
    0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00, 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71,
]);

pub const WAVE_UUID_MPEG: Uuid = Uuid::from_bytes([
    0x50, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00, 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71,
]);

pub const WAVE_UUID_BFORMAT_PCM: Uuid = Uuid::from_bytes([
    0x01, 0x00, 0x00, 0x00, 0x21, 0x07, 0xd3, 0x11, 0x86, 0x44, 0xc8, 0xc1, 0xca, 0x00, 0x00, 0x00,
]);

pub const WAVE_UUID_BFORMAT_FLOAT: Uuid = Uuid::from_bytes([
    0x03, 0x00, 0x00, 0x00, 0x21, 0x07, 0xd3, 0x11, 0x86, 0x44, 0xc8, 0xc1, 0xca, 0x00, 0x00, 0x00,
]);

fn uuid_from_basic_tag(tag: u16) -> Uuid {
    let tail: [u8; 6] = [0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71];
    Uuid::from_fields_le(tag as u32, 0x0000, 0x0010, &tail).unwrap()
}

/// Sample format of the Wave file.
///
///
#[derive(Debug, Copy, Clone, PartialEq)]
pub enum CommonFormat {
    /// Integer linear PCM
    IntegerPCM,

    /// IEEE Floating-point Linear PCM
    IeeeFloatPCM,

    /// MPEG
    Mpeg,

    /// Ambisonic B-Format Linear PCM
    AmbisonicBFormatIntegerPCM,

    /// Ambisonic B-Format Float PCM
    AmbisonicBFormatIeeeFloatPCM,

    /// An unknown format identified by a basic format tag.
    UnknownBasic(u16),

    /// An unknown format identified by an extension UUID.
    UnknownExtended(Uuid),
}

impl CommonFormat {
    /// Resolve a tag and Uuid to a `CommonFormat`.
    pub fn make(basic: u16, uuid: Option<Uuid>) -> Self {
        match (basic, uuid) {
            (WAVE_TAG_PCM, _) => Self::IntegerPCM,
            (WAVE_TAG_FLOAT, _) => Self::IeeeFloatPCM,
            (WAVE_TAG_MPEG, _) => Self::Mpeg,
            (WAVE_TAG_EXTENDED, Some(WAVE_UUID_PCM)) => Self::IntegerPCM,
            (WAVE_TAG_EXTENDED, Some(WAVE_UUID_FLOAT)) => Self::IeeeFloatPCM,
            (WAVE_TAG_EXTENDED, Some(WAVE_UUID_BFORMAT_PCM)) => Self::AmbisonicBFormatIntegerPCM,
            (WAVE_TAG_EXTENDED, Some(WAVE_UUID_BFORMAT_FLOAT)) => Self::AmbisonicBFormatIeeeFloatPCM,
            (WAVE_TAG_EXTENDED, Some(x)) => CommonFormat::UnknownExtended(x),
            (x, _) => CommonFormat::UnknownBasic(x),
        }
    }

    /// Get the appropriate tag and `Uuid` for the callee.
    ///
    /// If there is no appropriate tag for the format of the callee, the
    /// returned tag will be 0xFFFE and the `Uuid` will describe the format.
    pub fn take(self) -> (u16, Uuid) {
        match self {
            Self::IntegerPCM => (WAVE_TAG_PCM, WAVE_UUID_PCM),
            Self::IeeeFloatPCM => (WAVE_TAG_FLOAT, WAVE_UUID_FLOAT),
            Self::Mpeg => (WAVE_TAG_MPEG, WAVE_UUID_MPEG),
            Self::AmbisonicBFormatIntegerPCM => (WAVE_TAG_EXTENDED, WAVE_UUID_BFORMAT_PCM),
            Self::AmbisonicBFormatIeeeFloatPCM => (WAVE_TAG_EXTENDED, WAVE_UUID_BFORMAT_FLOAT),
            Self::UnknownBasic(x) => (x, uuid_from_basic_tag(x)),
            Self::UnknownExtended(x) => (WAVE_TAG_EXTENDED, x),
        }
    }
}