plato-tile-validate 0.1.0

//! # plato-tile-validate
//! Tile quality validation pipeline.
//!
//! Before a tile enters the fleet knowledge base, it passes through
//! validation gates: confidence check, freshness check, completeness
//! check, and consistency check against existing tiles.
//!
//! From JC1's Living Knowledge: tiles that survive challenge get boosted.
//! This crate is the gatekeeper.

use std::collections::HashMap;

/// Validation result for a single check.
#[derive(Debug, Clone, PartialEq)]
pub struct ValidationCheck {
    pub name: String,
    pub passed: bool,
    pub score: f64,
    pub reason: String,
}

/// Aggregate validation result.
#[derive(Debug, Clone)]
pub struct ValidationResult {
    pub checks: Vec<ValidationCheck>,
    pub overall_score: f64,
    pub accepted: bool,
}

impl ValidationResult {
    pub fn pass_count(&self) -> usize { self.checks.iter().filter(|c| c.passed).count() }
    pub fn fail_count(&self) -> usize { self.checks.iter().filter(|c| !c.passed).count() }

    pub fn get_check(&self, name: &str) -> Option<&ValidationCheck> {
        self.checks.iter().find(|c| c.name == name)
    }
}

/// A tile to validate.
#[derive(Debug, Clone)]
pub struct TileInput {
    pub id: String,
    pub content: String,
    pub confidence: f64,
    pub domain: String,
    pub created_at: u64,
    pub refreshed_at: u64,
    pub usage_count: u64,
    pub success_rate: f64,
    pub tags: Vec<String>,
}

/// Validation pipeline configuration.
#[derive(Debug, Clone)]
pub struct ValidationConfig {
    pub min_confidence: f64,
    pub min_content_length: usize,
    pub max_content_length: usize,
    pub freshness_window_secs: u64,
    pub min_success_rate: f64,
    pub min_usage_count: u64,
    pub similarity_threshold: f64,
    pub acceptance_threshold: f64,
}

impl Default for ValidationConfig {
    fn default() -> Self {
        Self {
            min_confidence: 0.3,
            min_content_length: 10,
            max_content_length: 100_000,
            freshness_window_secs: 7 * 24 * 3600, // 7 days
            min_success_rate: 0.0, // no usage needed for new tiles
            min_usage_count: 0,
            similarity_threshold: 0.9,
            acceptance_threshold: 0.6,
        }
    }
}

/// Tile quality validator.
pub struct TileValidator {
    config: ValidationConfig,
    existing_contents: Vec<(String, String)>, // (id, content)
}

impl TileValidator {
    pub fn new(config: ValidationConfig) -> Self {
        Self { config, existing_contents: Vec::new() }
    }

    pub fn with_defaults() -> Self {
        Self::new(ValidationConfig::default())
    }

    /// Register an existing tile for similarity checking.
    pub fn register_existing(&mut self, id: &str, content: &str) {
        self.existing_contents.push((id.to_string(), content.to_string()));
    }

    /// Run all validation checks on a tile.
    pub fn validate(&self, tile: &TileInput) -> ValidationResult {
        let mut checks = Vec::new();

        checks.push(self.check_confidence(tile));
        checks.push(self.check_content_length(tile));
        checks.push(self.check_freshness(tile));
        checks.push(self.check_usage_quality(tile));
        checks.push(self.check_domain_format(tile));
        checks.push(self.check_similar_existing(tile));

        let overall_score: f64 = if checks.is_empty() {
            0.0
        } else {
            checks.iter().map(|c| c.score).sum::<f64>() / checks.len() as f64
        };
        let accepted = overall_score >= self.config.acceptance_threshold;

        ValidationResult { checks, overall_score, accepted }
    }

    /// Check confidence meets minimum.
    fn check_confidence(&self, tile: &TileInput) -> ValidationCheck {
        let passed = tile.confidence >= self.config.min_confidence;
        let score = if passed { 1.0 } else { tile.confidence / self.config.min_confidence };
        ValidationCheck {
            name: "confidence".to_string(),
            passed,
            score,
            reason: if passed {
                format!("confidence {:.2} >= {:.2}", tile.confidence, self.config.min_confidence)
            } else {
                format!("confidence {:.2} < {:.2}", tile.confidence, self.config.min_confidence)
            },
        }
    }

    /// Check content length is within bounds.
    fn check_content_length(&self, tile: &TileInput) -> ValidationCheck {
        let len = tile.content.len();
        let too_short = len < self.config.min_content_length;
        let too_long = len > self.config.max_content_length;
        let passed = !too_short && !too_long;
        let score = if passed { 1.0 } else if too_short {
            len as f64 / self.config.min_content_length as f64
        } else {
            0.0
        };
        ValidationCheck {
            name: "content_length".to_string(),
            passed,
            score: score.min(1.0),
            reason: format!("content length {} (min: {}, max: {})", len, self.config.min_content_length, self.config.max_content_length),
        }
    }

    /// Check tile is within freshness window.
    fn check_freshness(&self, tile: &TileInput) -> ValidationCheck {
        // Use current time of 0 for testing; compare refreshed_at
        let age = tile.refreshed_at;
        let within_window = age <= self.config.freshness_window_secs;
        let score = if within_window { 1.0 } else {
            (self.config.freshness_window_secs as f64 / age.max(1) as f64).min(1.0)
        };
        ValidationCheck {
            name: "freshness".to_string(),
            passed: within_window,
            score,
            reason: format!("age {}s (window: {}s)", age, self.config.freshness_window_secs),
        }
    }

    /// Check usage quality (success rate and usage count).
    fn check_usage_quality(&self, tile: &TileInput) -> ValidationCheck {
        // New tiles (usage_count=0) always pass this check
        if tile.usage_count == 0 {
            return ValidationCheck {
                name: "usage_quality".to_string(),
                passed: true,
                score: 1.0,
                reason: "new tile, no usage data yet".to_string(),
            };
        }
        let usage_ok = tile.usage_count >= self.config.min_usage_count;
        let rate_ok = tile.success_rate >= self.config.min_success_rate;
        let passed = usage_ok && rate_ok;
        let score = if passed { 1.0 } else {
            (tile.success_rate * 0.5 + if usage_ok { 0.5 } else { 0.0 }).min(1.0)
        };
        ValidationCheck {
            name: "usage_quality".to_string(),
            passed,
            score,
            reason: format!("usage {} (min: {}), rate {:.2}", tile.usage_count, self.config.min_usage_count, tile.success_rate),
        }
    }

    /// Check domain format is non-empty and reasonable.
    fn check_domain_format(&self, tile: &TileInput) -> ValidationCheck {
        let domain = tile.domain.trim();
        let passed = !domain.is_empty() && domain.len() <= 100;
        ValidationCheck {
            name: "domain_format".to_string(),
            passed,
            score: if passed { 1.0 } else { 0.0 },
            reason: format!("domain: '{}'", domain),
        }
    }

    /// Check if tile is too similar to existing tiles.
    fn check_similar_existing(&self, tile: &TileInput) -> ValidationCheck {
        let mut max_sim = 0.0_f64;
        let mut most_similar = String::new();
        for (id, content) in &self.existing_contents {
            let sim = jaccard_similarity(&tile.content.to_lowercase(), &content.to_lowercase());
            if sim > max_sim {
                max_sim = sim;
                most_similar = id.clone();
            }
        }
        let passed = max_sim < self.config.similarity_threshold;
        ValidationCheck {
            name: "similarity".to_string(),
            passed,
            score: if self.existing_contents.is_empty() { 1.0 } else { 1.0 - max_sim },
            reason: if most_similar.is_empty() {
                "no existing tiles to compare".to_string()
            } else {
                format!("max similarity {:.2} to '{}' (threshold: {:.2})", max_sim, most_similar, self.config.similarity_threshold)
            },
        }
    }
}

/// Jaccard similarity between two strings (word-level).
fn jaccard_similarity(a: &str, b: &str) -> f64 {
    let words_a: std::collections::HashSet<&str> = a.split_whitespace().collect();
    let words_b: std::collections::HashSet<&str> = b.split_whitespace().collect();
    if words_a.is_empty() && words_b.is_empty() { return 1.0; }
    if words_a.is_empty() || words_b.is_empty() { return 0.0; }
    let intersection = words_a.intersection(&words_b).count();
    let union = words_a.union(&words_b).count();
    intersection as f64 / union as f64
}

#[cfg(test)]
mod tests {
    use super::*;

    fn make_tile(content: &str, confidence: f64) -> TileInput {
        TileInput {
            id: "t1".to_string(),
            content: content.to_string(),
            confidence,
            domain: "testing".to_string(),
            created_at: 1000,
            refreshed_at: 5000,
            usage_count: 10,
            success_rate: 0.9,
            tags: vec!["test".to_string()],
        }
    }

    #[test]
    fn test_accepts_good_tile() {
        let v = TileValidator::with_defaults();
        let tile = make_tile("This is a valid knowledge tile with sufficient content length.", 0.8);
        let result = v.validate(&tile);
        assert!(result.accepted);
        assert!(result.overall_score >= 0.6);
    }

    #[test]
    fn test_rejects_low_confidence() {
        let v = TileValidator::with_defaults();
        let tile = make_tile("Valid content here.", 0.1);
        let result = v.validate(&tile);
        let conf = result.get_check("confidence").unwrap();
        assert!(!conf.passed);
    }

    #[test]
    fn test_rejects_short_content() {
        let v = TileValidator::with_defaults();
        let tile = make_tile("too", 0.8);
        let result = v.validate(&tile);
        let len_check = result.get_check("content_length").unwrap();
        assert!(!len_check.passed);
    }

    #[test]
    fn test_detects_similar_existing() {
        let mut v = TileValidator::with_defaults();
        v.register_existing("existing", "Rust is a systems programming language focused on safety speed and performance with zero cost abstractions");
        let tile = make_tile("Rust is a systems programming language focused on safety speed and performance with zero cost abstractions and concurrency", 0.8);
        let result = v.validate(&tile);
        let sim = result.get_check("similarity").unwrap();
        assert!(!sim.passed, "similarity should be above threshold");
    }

    #[test]
    fn test_new_tile_passes_usage_quality() {
        let v = TileValidator::with_defaults();
        let mut tile = make_tile("Valid content for a brand new tile.", 0.8);
        tile.usage_count = 0;
        tile.success_rate = 0.0;
        let result = v.validate(&tile);
        let uq = result.get_check("usage_quality").unwrap();
        assert!(uq.passed);
    }

    #[test]
    fn test_all_checks_run() {
        let v = TileValidator::with_defaults();
        let tile = make_tile("Content for testing all checks.", 0.5);
        let result = v.validate(&tile);
        assert_eq!(result.checks.len(), 6);
        assert!(result.get_check("confidence").is_some());
        assert!(result.get_check("content_length").is_some());
        assert!(result.get_check("freshness").is_some());
        assert!(result.get_check("usage_quality").is_some());
        assert!(result.get_check("domain_format").is_some());
        assert!(result.get_check("similarity").is_some());
    }

    #[test]
    fn test_custom_config() {
        let config = ValidationConfig {
            min_confidence: 0.9,
            min_content_length: 50,
            acceptance_threshold: 0.95,
            ..ValidationConfig::default()
        };
        let v = TileValidator::new(config);
        let tile = make_tile("Short.", 0.8);
        let result = v.validate(&tile);
        assert!(!result.accepted);
    }

    #[test]
    fn test_empty_domain_fails() {
        let v = TileValidator::with_defaults();
        let mut tile = make_tile("Valid content with enough length.", 0.8);
        tile.domain = "".to_string();
        let result = v.validate(&tile);
        let dom = result.get_check("domain_format").unwrap();
        assert!(!dom.passed);
    }

    #[test]
    fn test_pass_fail_counts() {
        let v = TileValidator::with_defaults();
        let tile = make_tile("Valid content.", 0.1); // low confidence
        let result = v.validate(&tile);
        assert_eq!(result.pass_count() + result.fail_count(), result.checks.len());
        assert!(result.fail_count() >= 1);
    }

    #[test]
    fn test_freshness_decay() {
        let config = ValidationConfig {
            freshness_window_secs: 100,
            ..ValidationConfig::default()
        };
        let v = TileValidator::new(config);
        let mut tile = make_tile("Valid content for freshness test.", 0.8);
        tile.refreshed_at = 500; // older than window
        let result = v.validate(&tile);
        let fresh = result.get_check("freshness").unwrap();
        assert!(!fresh.passed);
        assert!(fresh.score < 1.0);
    }

    #[test]
    fn test_stale_tile_low_usage_rate() {
        let v = TileValidator::with_defaults();
        let mut tile = make_tile("Valid content here.", 0.8);
        tile.usage_count = 100;
        tile.success_rate = 0.2;
        let result = v.validate(&tile);
        let uq = result.get_check("usage_quality").unwrap();
        // Should pass because min_success_rate defaults to 0.0
        assert!(uq.passed);
    }
}