solverforge-core 0.8.1

/* HardSoftDecimalScore - Two-level score with i64 precision and x100000 scaling

This score type represents a decimal score without heap allocation.
Internal values are scaled by 100000 to provide 5 decimal places of precision.
*/

use std::cmp::Ordering;
use std::fmt;

use super::traits::{ParseableScore, Score, ScoreParseError};
use super::ScoreLevel;

// Scale factor for 5 decimal places of precision.
const SCALE: i64 = 100_000;

/* A score with separate hard and soft constraint levels, using i64 with x100000 scaling.

This provides 5 decimal places of precision while maintaining zero heap allocation
and full type safety.

Internal values are stored pre-scaled. Use [`of`](Self::of) for unscaled input
or [`of_scaled`](Self::of_scaled) for pre-scaled values.

# Examples

```
use solverforge_core::{HardSoftDecimalScore, Score};

// Create from unscaled values (automatically multiplied by 100000)
let score1 = HardSoftDecimalScore::of(-1, -100);
assert_eq!(score1.hard_scaled(), -100000);
assert_eq!(score1.soft_scaled(), -10000000);

// Create from pre-scaled values (for minute-based penalties)
let score2 = HardSoftDecimalScore::of_scaled(-3050000, 0);  // -30.5 hard
assert!(!score2.is_feasible());

// Display shows values (trailing zeros stripped)
let score3 = HardSoftDecimalScore::of_scaled(-150000, -250000);
assert_eq!(format!("{}", score3), "-1.5hard/-2.5soft");
```
*/
#[derive(Clone, Copy, PartialEq, Eq, Hash, Default)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub struct HardSoftDecimalScore {
    hard: i64,
    soft: i64,
}

impl HardSoftDecimalScore {
    /// The zero score.
    pub const ZERO: HardSoftDecimalScore = HardSoftDecimalScore { hard: 0, soft: 0 };

    /// One hard constraint penalty (scaled).
    pub const ONE_HARD: HardSoftDecimalScore = HardSoftDecimalScore {
        hard: SCALE,
        soft: 0,
    };

    /// One soft constraint penalty (scaled).
    pub const ONE_SOFT: HardSoftDecimalScore = HardSoftDecimalScore {
        hard: 0,
        soft: SCALE,
    };

    /* Creates a new score from unscaled values.

    The values are automatically multiplied by 100000.

    # Examples

    ```
    use solverforge_core::HardSoftDecimalScore;

    let score = HardSoftDecimalScore::of(-2, -100);
    assert_eq!(score.hard_scaled(), -200000);
    assert_eq!(score.soft_scaled(), -10000000);
    ```
    */
    #[inline]
    pub const fn of(hard: i64, soft: i64) -> Self {
        HardSoftDecimalScore {
            hard: hard * SCALE,
            soft: soft * SCALE,
        }
    }

    /* Creates a new score from pre-scaled values.

    Use this for minute-based penalties where precision matters.

    # Examples

    ```
    use solverforge_core::HardSoftDecimalScore;

    // -30.5 hard constraint (overlap of 30.5 minutes)
    let score = HardSoftDecimalScore::of_scaled(-3050000, 0);
    assert_eq!(score.hard_scaled(), -3050000);
    ```
    */
    #[inline]
    pub const fn of_scaled(hard: i64, soft: i64) -> Self {
        HardSoftDecimalScore { hard, soft }
    }

    #[inline]
    pub const fn of_hard(hard: i64) -> Self {
        HardSoftDecimalScore {
            hard: hard * SCALE,
            soft: 0,
        }
    }

    #[inline]
    pub const fn of_soft(soft: i64) -> Self {
        HardSoftDecimalScore {
            hard: 0,
            soft: soft * SCALE,
        }
    }

    #[inline]
    pub const fn of_hard_scaled(hard: i64) -> Self {
        HardSoftDecimalScore { hard, soft: 0 }
    }

    #[inline]
    pub const fn of_soft_scaled(soft: i64) -> Self {
        HardSoftDecimalScore { hard: 0, soft }
    }

    #[inline]
    pub const fn hard_scaled(&self) -> i64 {
        self.hard
    }

    #[inline]
    pub const fn soft_scaled(&self) -> i64 {
        self.soft
    }

    pub const fn hard_score(&self) -> HardSoftDecimalScore {
        HardSoftDecimalScore::of_scaled(self.hard, 0)
    }

    pub const fn soft_score(&self) -> HardSoftDecimalScore {
        HardSoftDecimalScore::of_scaled(0, self.soft)
    }

    /* Returns true if this score has a non-zero hard component.

    Used by constraint streams to determine if a weight represents
    a hard or soft constraint.
    */
    #[inline]
    pub const fn has_hard_component(&self) -> bool {
        self.hard != 0
    }
}

impl Score for HardSoftDecimalScore {
    #[inline]
    fn is_feasible(&self) -> bool {
        self.hard >= 0
    }

    #[inline]
    fn zero() -> Self {
        HardSoftDecimalScore::ZERO
    }

    #[inline]
    fn levels_count() -> usize {
        2
    }

    fn to_level_numbers(&self) -> Vec<i64> {
        vec![self.hard, self.soft]
    }

    fn from_level_numbers(levels: &[i64]) -> Self {
        assert_eq!(
            levels.len(),
            2,
            "HardSoftDecimalScore requires exactly 2 levels"
        );
        HardSoftDecimalScore::of_scaled(levels[0], levels[1])
    }

    impl_score_scale!(HardSoftDecimalScore { hard, soft } => of_scaled);

    fn level_label(index: usize) -> ScoreLevel {
        match index {
            0 => ScoreLevel::Hard,
            1 => ScoreLevel::Soft,
            _ => panic!("HardSoftDecimalScore has 2 levels, got index {}", index),
        }
    }

    #[inline]
    fn to_scalar(&self) -> f64 {
        self.hard as f64 * 1_000_000.0 + self.soft as f64
    }
}

impl Ord for HardSoftDecimalScore {
    fn cmp(&self, other: &Self) -> Ordering {
        match self.hard.cmp(&other.hard) {
            Ordering::Equal => self.soft.cmp(&other.soft),
            other => other,
        }
    }
}

impl_score_ops!(HardSoftDecimalScore { hard, soft } => of_scaled);

impl fmt::Debug for HardSoftDecimalScore {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(
            f,
            "HardSoftDecimalScore({:.3}, {:.3})",
            self.hard as f64 / SCALE as f64,
            self.soft as f64 / SCALE as f64
        )
    }
}

impl fmt::Display for HardSoftDecimalScore {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        fn format_score_part(scaled: i64) -> String {
            if scaled % SCALE == 0 {
                // Integer value, no decimals needed
                (scaled / SCALE).to_string()
            } else {
                // Has decimal part - format with precision and strip trailing zeros
                let value = scaled as f64 / SCALE as f64;
                let formatted = format!("{:.6}", value);
                formatted
                    .trim_end_matches('0')
                    .trim_end_matches('.')
                    .to_string()
            }
        }
        write!(
            f,
            "{}hard/{}soft",
            format_score_part(self.hard),
            format_score_part(self.soft)
        )
    }
}

// HardSoftDecimalScore has custom parse logic (f64 parsing with scaling) so no macro.
impl ParseableScore for HardSoftDecimalScore {
    fn parse(s: &str) -> Result<Self, ScoreParseError> {
        let s = s.trim();

        // Format: "0.000hard/-100.500soft" or "-1hard/0soft"
        let parts: Vec<&str> = s.split('/').collect();
        if parts.len() != 2 {
            return Err(ScoreParseError {
                message: format!(
                    "Invalid HardSoftDecimalScore format '{}': expected 'Xhard/Ysoft'",
                    s
                ),
            });
        }

        let hard_str = parts[0]
            .trim()
            .strip_suffix("hard")
            .ok_or_else(|| ScoreParseError {
                message: format!("Hard score part '{}' must end with 'hard'", parts[0]),
            })?;

        let soft_str = parts[1]
            .trim()
            .strip_suffix("soft")
            .ok_or_else(|| ScoreParseError {
                message: format!("Soft score part '{}' must end with 'soft'", parts[1]),
            })?;

        let hard_float = hard_str.parse::<f64>().map_err(|e| ScoreParseError {
            message: format!("Invalid hard score '{}': {}", hard_str, e),
        })?;

        let soft_float = soft_str.parse::<f64>().map_err(|e| ScoreParseError {
            message: format!("Invalid soft score '{}': {}", soft_str, e),
        })?;

        // Convert to scaled integers
        let hard = (hard_float * SCALE as f64).round() as i64;
        let soft = (soft_float * SCALE as f64).round() as i64;

        Ok(HardSoftDecimalScore::of_scaled(hard, soft))
    }

    fn to_string_repr(&self) -> String {
        format!("{}", self)
    }
}