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use crate::error::EngineError;

#[derive(Debug, PartialEq, Copy, Clone)]
pub enum Meaning {
    Plain,
    Delta,
    Time,
}

impl Meaning {
    pub fn combine(
        self,
        other: Meaning,
        plain: fn(Meaning) -> Result<Meaning, EngineError>,
        delta: fn(Meaning) -> Result<Meaning, EngineError>,
        time: fn(Meaning) -> Result<Meaning, EngineError>,
    ) -> Result<Meaning, EngineError> {
        match self {
            Meaning::Plain => plain(other),
            Meaning::Delta => delta(other),
            Meaning::Time => time(other),
        }
    }

    pub fn pdt(self) -> Result<Meaning, EngineError> {
        match self {
            Meaning::Plain => Ok(Meaning::Plain),
            Meaning::Delta => Ok(Meaning::Delta),
            Meaning::Time => Ok(Meaning::Time),
        }
    }

    pub fn pdx(self) -> Result<Meaning, EngineError> {
        match self {
            Meaning::Plain => Ok(Meaning::Plain),
            Meaning::Delta => Ok(Meaning::Delta),
            Meaning::Time => Err(EngineError::BadTimeOp),
        }
    }

    pub fn pxx(self) -> Result<Meaning, EngineError> {
        match self {
            Meaning::Plain => Ok(Meaning::Plain),
            Meaning::Delta => Err(EngineError::BadTimeOp),
            Meaning::Time => Err(EngineError::BadTimeOp),
        }
    }

    pub fn ddt(self) -> Result<Meaning, EngineError> {
        match self {
            Meaning::Plain => Ok(Meaning::Delta),
            Meaning::Delta => Ok(Meaning::Delta),
            Meaning::Time => Ok(Meaning::Time),
        }
    }

    pub fn ddx(self) -> Result<Meaning, EngineError> {
        match self {
            Meaning::Plain => Ok(Meaning::Delta),
            Meaning::Delta => Ok(Meaning::Delta),
            Meaning::Time => Err(EngineError::BadTimeOp),
        }
    }

    pub fn dxx(self) -> Result<Meaning, EngineError> {
        match self {
            Meaning::Plain => Ok(Meaning::Delta),
            Meaning::Delta => Err(EngineError::BadTimeOp),
            Meaning::Time => Err(EngineError::BadTimeOp),
        }
    }

    pub fn ttd(self) -> Result<Meaning, EngineError> {
        match self {
            Meaning::Plain => Ok(Meaning::Time),
            Meaning::Delta => Ok(Meaning::Time),
            Meaning::Time => Ok(Meaning::Delta),
        }
    }

    pub fn ttx(self) -> Result<Meaning, EngineError> {
        match self {
            Meaning::Plain => Ok(Meaning::Time),
            Meaning::Delta => Ok(Meaning::Time),
            Meaning::Time => Err(EngineError::BadTimeOp),
        }
    }

    pub fn xxx(self) -> Result<Meaning, EngineError> {
        match self {
            Meaning::Plain => Err(EngineError::BadTimeOp),
            Meaning::Delta => Err(EngineError::BadTimeOp),
            Meaning::Time => Err(EngineError::BadTimeOp),
        }
    }
}