reputation-core 0.1.0

//! Enhanced builder pattern for Calculator construction
//! 
//! Provides a fluent API for creating Calculator instances with
//! custom configurations, presets, and bonus settings.

use crate::{Calculator, Result, BuilderError, CalculatorConfig};

/// Configuration for prior score bonuses
#[derive(Debug, Clone)]
pub struct BonusConfig {
    /// MCP level bonuses (per level)
    pub mcp_bonus_per_level: f64,
    /// Identity verification bonus
    pub identity_bonus: f64,
    /// Security audit bonus
    pub security_audit_bonus: f64,
    /// Open source bonus
    pub open_source_bonus: f64,
    /// Age bonus (for agents > 365 days)
    pub age_bonus: f64,
}

impl Default for BonusConfig {
    fn default() -> Self {
        Self {
            mcp_bonus_per_level: 5.0,
            identity_bonus: 5.0,
            security_audit_bonus: 7.0,
            open_source_bonus: 3.0,
            age_bonus: 5.0,
        }
    }
}

/// Preset configurations for common scenarios
#[derive(Debug, Clone, Copy, PartialEq)]
pub enum CalculatorPreset {
    /// Fast confidence growth for testing (k=5.0)
    Testing,
    /// Slow confidence growth for conservative scoring (k=30.0)
    Conservative,
    /// Medium confidence growth for balanced scoring (k=10.0)
    Aggressive,
    /// Standard default configuration
    Default,
}

/// Enhanced builder for creating Calculator instances
/// 
/// Provides a fluent API with validation, presets, and custom bonus configurations.
/// 
/// # Example
/// 
/// ```
/// use reputation_core::{Calculator, CalculatorPreset};
/// 
/// // Using presets
/// let calc = Calculator::builder()
///     .preset(CalculatorPreset::Testing)
///     .build()
///     .unwrap();
/// 
/// // Custom configuration
/// let calc = Calculator::builder()
///     .confidence_k(20.0)
///     .prior_base(60.0)
///     .prior_max(90.0)
///     .build()
///     .unwrap();
/// ```
#[derive(Debug, Clone)]
pub struct CalculatorBuilder {
    confidence_k: Option<f64>,
    prior_base: Option<f64>,
    prior_max: Option<f64>,
    bonuses: Option<BonusConfig>,
    preset_applied: Option<CalculatorPreset>,
}

impl Default for CalculatorBuilder {
    fn default() -> Self {
        Self {
            confidence_k: None,
            prior_base: None,
            prior_max: None,
            bonuses: None,
            preset_applied: None,
        }
    }
}

impl CalculatorBuilder {
    /// Create a new builder with no configuration
    pub fn new() -> Self {
        Self::default()
    }
    
    /// Set confidence growth parameter (k in the formula)
    /// 
    /// Higher values result in slower confidence growth.
    /// Must be positive.
    /// 
    /// # Example
    /// 
    /// ```
    /// use reputation_core::Calculator;
    /// 
    /// let calc = Calculator::builder()
    ///     .confidence_k(20.0)  // Slower growth
    ///     .build()
    ///     .unwrap();
    /// ```
    pub fn confidence_k(mut self, k: f64) -> Self {
        self.confidence_k = Some(k);
        self
    }
    
    /// Set base prior score (starting reputation)
    /// 
    /// Must be between 0 and 100.
    /// 
    /// # Example
    /// 
    /// ```
    /// use reputation_core::Calculator;
    /// 
    /// let calc = Calculator::builder()
    ///     .prior_base(60.0)  // Higher starting score
    ///     .build()
    ///     .unwrap();
    /// ```
    pub fn prior_base(mut self, base: f64) -> Self {
        self.prior_base = Some(base);
        self
    }
    
    /// Set maximum prior score (cap for credential bonuses)
    /// 
    /// Must be between prior_base and 100.
    /// 
    /// # Example
    /// 
    /// ```
    /// use reputation_core::Calculator;
    /// 
    /// let calc = Calculator::builder()
    ///     .prior_base(50.0)
    ///     .prior_max(85.0)  // Higher ceiling
    ///     .build()
    ///     .unwrap();
    /// ```
    pub fn prior_max(mut self, max: f64) -> Self {
        self.prior_max = Some(max);
        self
    }
    
    /// Set custom bonus configuration
    /// 
    /// Allows fine-tuning of individual credential bonuses.
    /// 
    /// # Example
    /// 
    /// ```
    /// use reputation_core::{Calculator, BonusConfig};
    /// 
    /// let bonuses = BonusConfig {
    ///     mcp_bonus_per_level: 7.0,  // Higher MCP bonus
    ///     identity_bonus: 10.0,      // Higher identity bonus
    ///     ..Default::default()
    /// };
    /// 
    /// let calc = Calculator::builder()
    ///     .prior_bonuses(bonuses)
    ///     .build()
    ///     .unwrap();
    /// ```
    pub fn prior_bonuses(mut self, bonuses: BonusConfig) -> Self {
        self.bonuses = Some(bonuses);
        self
    }
    
    /// Apply a preset configuration
    /// 
    /// Presets provide tested configurations for common scenarios.
    /// Individual settings can still be overridden after applying a preset.
    /// 
    /// # Example
    /// 
    /// ```
    /// use reputation_core::{Calculator, CalculatorPreset};
    /// 
    /// // Use testing preset with custom prior_base
    /// let calc = Calculator::builder()
    ///     .preset(CalculatorPreset::Testing)
    ///     .prior_base(55.0)  // Override preset's prior_base
    ///     .build()
    ///     .unwrap();
    /// ```
    pub fn preset(mut self, preset: CalculatorPreset) -> Self {
        self.preset_applied = Some(preset);
        
        // Apply preset values (can be overridden by subsequent calls)
        match preset {
            CalculatorPreset::Testing => {
                self.confidence_k = Some(5.0);
                self.prior_base = Some(50.0);
                self.prior_max = Some(80.0);
            }
            CalculatorPreset::Conservative => {
                self.confidence_k = Some(30.0);
                self.prior_base = Some(60.0);
                self.prior_max = Some(80.0);
            }
            CalculatorPreset::Aggressive => {
                self.confidence_k = Some(10.0);
                self.prior_base = Some(40.0);
                self.prior_max = Some(90.0);
            }
            CalculatorPreset::Default => {
                self.confidence_k = Some(15.0);
                self.prior_base = Some(50.0);
                self.prior_max = Some(80.0);
            }
        }
        
        self
    }
    
    /// Load configuration from a CalculatorConfig
    /// 
    /// # Example
    /// 
    /// ```
    /// use reputation_core::{Calculator, CalculatorConfig};
    /// 
    /// let config = CalculatorConfig::default();
    /// let calc = Calculator::builder()
    ///     .from_config(config)
    ///     .build()
    ///     .unwrap();
    /// ```
    pub fn from_config(mut self, config: CalculatorConfig) -> Self {
        self.confidence_k = Some(config.confidence_k);
        self.prior_base = Some(config.prior_base);
        self.prior_max = Some(config.prior_max);
        self
    }
    
    /// Get the current configuration (for inspection)
    pub fn config(&self) -> CalculatorConfig {
        CalculatorConfig {
            confidence_k: self.confidence_k.unwrap_or(15.0),
            prior_base: self.prior_base.unwrap_or(50.0),
            prior_max: self.prior_max.unwrap_or(80.0),
        }
    }
    
    /// Build the Calculator with validation
    /// 
    /// # Errors
    /// 
    /// Returns an error if:
    /// - confidence_k <= 0
    /// - prior_base < 0 or > 100
    /// - prior_max < prior_base or > 100
    /// 
    /// # Example
    /// 
    /// ```
    /// use reputation_core::Calculator;
    /// 
    /// let result = Calculator::builder()
    ///     .confidence_k(-5.0)  // Invalid!
    ///     .build();
    /// 
    /// assert!(result.is_err());
    /// ```
    pub fn build(self) -> Result<Calculator> {
        let config = self.config();
        
        // Validate configuration
        if config.confidence_k <= 0.0 {
            return Err(BuilderError::InvalidConfig(
                "confidence_k must be positive".to_string()
            ).into());
        }
        
        if config.prior_base < 0.0 || config.prior_base > 100.0 {
            return Err(BuilderError::InvalidConfig(
                "prior_base must be between 0 and 100".to_string()
            ).into());
        }
        
        if config.prior_max <= config.prior_base {
            return Err(BuilderError::InvalidConfig(
                format!("prior_max must be greater than prior_base ({})", config.prior_base)
            ).into());
        }
        
        if config.prior_max > 100.0 {
            return Err(BuilderError::InvalidConfig(
                "prior_max must not exceed 100".to_string()
            ).into());
        }
        
        // Create calculator
        // Note: In a real implementation, we might pass the bonus config to the Calculator
        // For now, we'll use the standard constructor
        Calculator::new(config.confidence_k, config.prior_base, config.prior_max)
    }
    
    /// Reset the builder to default state
    pub fn reset(mut self) -> Self {
        self.confidence_k = None;
        self.prior_base = None;
        self.prior_max = None;
        self.bonuses = None;
        self.preset_applied = None;
        self
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    
    #[test]
    fn test_builder_defaults() {
        let calc = CalculatorBuilder::new().build().unwrap();
        assert_eq!(calc.confidence_k, 15.0);
        assert_eq!(calc.prior_base, 50.0);
        assert_eq!(calc.prior_max, 80.0);
    }
    
    #[test]
    fn test_builder_custom_values() {
        let calc = CalculatorBuilder::new()
            .confidence_k(25.0)
            .prior_base(55.0)
            .prior_max(85.0)
            .build()
            .unwrap();
            
        assert_eq!(calc.confidence_k, 25.0);
        assert_eq!(calc.prior_base, 55.0);
        assert_eq!(calc.prior_max, 85.0);
    }
    
    #[test]
    fn test_preset_testing() {
        let calc = CalculatorBuilder::new()
            .preset(CalculatorPreset::Testing)
            .build()
            .unwrap();
            
        assert_eq!(calc.confidence_k, 5.0);
        assert_eq!(calc.prior_base, 50.0);
        assert_eq!(calc.prior_max, 80.0);
    }
    
    #[test]
    fn test_preset_conservative() {
        let calc = CalculatorBuilder::new()
            .preset(CalculatorPreset::Conservative)
            .build()
            .unwrap();
            
        assert_eq!(calc.confidence_k, 30.0);
        assert_eq!(calc.prior_base, 60.0);
        assert_eq!(calc.prior_max, 80.0);
    }
    
    #[test]
    fn test_preset_aggressive() {
        let calc = CalculatorBuilder::new()
            .preset(CalculatorPreset::Aggressive)
            .build()
            .unwrap();
            
        assert_eq!(calc.confidence_k, 10.0);
        assert_eq!(calc.prior_base, 40.0);
        assert_eq!(calc.prior_max, 90.0);
    }
    
    #[test]
    fn test_preset_override() {
        // Apply preset then override specific values
        let calc = CalculatorBuilder::new()
            .preset(CalculatorPreset::Testing)
            .confidence_k(8.0)  // Override preset
            .build()
            .unwrap();
            
        assert_eq!(calc.confidence_k, 8.0);  // Overridden
        assert_eq!(calc.prior_base, 50.0);   // From preset
        assert_eq!(calc.prior_max, 80.0);    // From preset
    }
    
    #[test]
    fn test_validation_confidence_k() {
        let result = CalculatorBuilder::new()
            .confidence_k(0.0)
            .build();
        assert!(result.is_err());
        
        let result = CalculatorBuilder::new()
            .confidence_k(-5.0)
            .build();
        assert!(result.is_err());
    }
    
    #[test]
    fn test_validation_prior_base() {
        let result = CalculatorBuilder::new()
            .prior_base(-10.0)
            .build();
        assert!(result.is_err());
        
        let result = CalculatorBuilder::new()
            .prior_base(105.0)
            .build();
        assert!(result.is_err());
    }
    
    #[test]
    fn test_validation_prior_max() {
        // Max less than base
        let result = CalculatorBuilder::new()
            .prior_base(60.0)
            .prior_max(50.0)
            .build();
        assert!(result.is_err());
        
        // Max equal to base
        let result = CalculatorBuilder::new()
            .prior_base(60.0)
            .prior_max(60.0)
            .build();
        assert!(result.is_err());
        
        // Max over 100
        let result = CalculatorBuilder::new()
            .prior_max(105.0)
            .build();
        assert!(result.is_err());
    }
    
    #[test]
    fn test_builder_clone() {
        let builder = CalculatorBuilder::new()
            .confidence_k(20.0)
            .prior_base(60.0);
            
        let builder2 = builder.clone()
            .prior_max(85.0);
            
        let calc1 = builder.build().unwrap();
        let calc2 = builder2.build().unwrap();
        
        assert_eq!(calc1.confidence_k, 20.0);
        assert_eq!(calc1.prior_max, 80.0);  // Default
        
        assert_eq!(calc2.confidence_k, 20.0);
        assert_eq!(calc2.prior_max, 85.0);  // Modified
    }
    
    #[test]
    fn test_builder_reset() {
        let builder = CalculatorBuilder::new()
            .confidence_k(20.0)
            .prior_base(60.0)
            .reset();
            
        let calc = builder.build().unwrap();
        
        // Should have defaults after reset
        assert_eq!(calc.confidence_k, 15.0);
        assert_eq!(calc.prior_base, 50.0);
        assert_eq!(calc.prior_max, 80.0);
    }
    
    #[test]
    fn test_from_config() {
        let config = CalculatorConfig {
            confidence_k: 22.0,
            prior_base: 58.0,
            prior_max: 88.0,
        };
        
        let calc = CalculatorBuilder::new()
            .from_config(config)
            .build()
            .unwrap();
            
        assert_eq!(calc.confidence_k, 22.0);
        assert_eq!(calc.prior_base, 58.0);
        assert_eq!(calc.prior_max, 88.0);
    }
    
    #[test]
    fn test_bonus_config_default() {
        let bonuses = BonusConfig::default();
        assert_eq!(bonuses.mcp_bonus_per_level, 5.0);
        assert_eq!(bonuses.identity_bonus, 5.0);
        assert_eq!(bonuses.security_audit_bonus, 7.0);
        assert_eq!(bonuses.open_source_bonus, 3.0);
        assert_eq!(bonuses.age_bonus, 5.0);
    }
    
    #[test]
    fn test_method_chaining() {
        // Test that all methods can be chained
        let _calc = CalculatorBuilder::new()
            .preset(CalculatorPreset::Testing)
            .confidence_k(10.0)
            .prior_base(55.0)
            .prior_max(85.0)
            .prior_bonuses(BonusConfig::default())
            .build()
            .unwrap();
    }
}