//! 学习触发信号系统
//!
//! 规则驱动的低成本触发判断，在 `post_conversation_hook` 中调用。
//! 有信号时才进入 LLM 经验提取，无信号则零成本跳过。

use super::experience::{CompletionStatus, detect_implicit_feedback};

/// 触发信号类型
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum TriggerSignal {
    /// 痛点确认（confidence >= 0.7）
    PainConfirmed,
    /// 隐式正反馈（"谢谢/解决了/对了/好了"）
    PositiveFeedback,
    /// 复杂工具链（单次对话 3+ tool calls）
    ComplexToolChain,
    /// 用户纠正（含"不对/不是/应该是"）
    UserCorrection,
    /// 行业模式（同一行业关键词在多轮出现）
    IndustryPattern,
}

/// 触发信号判断的输入
pub struct TriggerContext {
    /// 最新用户消息
    pub user_message: String,
    /// 本轮工具调用次数
    pub tool_call_count: usize,
    /// 对话中累计的用户消息（用于行业关键词统计）
    pub conversation_messages: Vec<String>,
    /// 检测到的痛点置信度（如有）
    pub pain_confidence: Option<f64>,
    /// 用户授权的行业关键词
    pub industry_keywords: Vec<String>,
}

/// 判断是否触发学习信号（纯规则，零 LLM 调用）
///
/// 返回匹配到的所有触发信号。空 Vec = 无信号，跳过。
pub fn evaluate_triggers(ctx: &TriggerContext) -> Vec<TriggerSignal> {
    let mut signals = Vec::new();

    // 1. 痛点确认
    if let Some(confidence) = ctx.pain_confidence {
        if confidence >= 0.7 {
            signals.push(TriggerSignal::PainConfirmed);
        }
    }

    // 2. 隐式正反馈
    if let Some(status) = detect_implicit_feedback(&ctx.user_message) {
        if status == CompletionStatus::Success {
            signals.push(TriggerSignal::PositiveFeedback);
        }
    }

    // 3. 复杂工具链
    if ctx.tool_call_count >= 3 {
        signals.push(TriggerSignal::ComplexToolChain);
    }

    // 4. 用户纠正
    if is_user_correction(&ctx.user_message) {
        signals.push(TriggerSignal::UserCorrection);
    }

    // 5. 行业模式
    if detects_industry_pattern(&ctx.conversation_messages, &ctx.industry_keywords) {
        signals.push(TriggerSignal::IndustryPattern);
    }

    signals
}

/// 检测用户纠正信号
fn is_user_correction(message: &str) -> bool {
    let lower = message.to_lowercase();
    let correction_patterns = [
        "不对", "不是", "应该是", "错了", "重新", "换一个",
        "不是这个", "搞错了", "你理解错了", "我的意思是",
    ];
    correction_patterns.iter().any(|p| lower.contains(p))
}

/// 检测行业关键词在多轮对话中反复出现
fn detects_industry_pattern(messages: &[String], industry_keywords: &[String]) -> bool {
    if messages.len() < 3 || industry_keywords.is_empty() {
        return false;
    }

    // 统计行业关键词在所有消息中的出现次数
    let mut keyword_hits: std::collections::HashMap<&str, usize> = std::collections::HashMap::new();
    for msg in messages {
        let lower = msg.to_lowercase();
        for kw in industry_keywords {
            if lower.contains(kw.to_lowercase().as_str()) {
                *keyword_hits.entry(kw).or_default() += 1;
            }
        }
    }

    // 至少有 1 个关键词在 3+ 轮中出现
    keyword_hits.values().any(|&count| count >= 3)
}

/// 触发信号的可读描述（用于日志）
pub fn signal_description(signal: &TriggerSignal) -> &'static str {
    match signal {
        TriggerSignal::PainConfirmed => "痛点确认",
        TriggerSignal::PositiveFeedback => "隐式正反馈",
        TriggerSignal::ComplexToolChain => "复杂工具链",
        TriggerSignal::UserCorrection => "用户纠正",
        TriggerSignal::IndustryPattern => "行业模式",
    }
}

// ---------------------------------------------------------------------------
// Tests
// ---------------------------------------------------------------------------

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

    #[test]
    fn test_pain_confirmed_trigger() {
        let ctx = TriggerContext {
            user_message: "这个报表还是有问题".to_string(),
            tool_call_count: 1,
            conversation_messages: vec!["报表太慢".into()],
            pain_confidence: Some(0.8),
            industry_keywords: vec![],
        };
        let signals = evaluate_triggers(&ctx);
        assert!(signals.contains(&TriggerSignal::PainConfirmed));
    }

    #[test]
    fn test_positive_feedback_trigger() {
        let ctx = TriggerContext {
            user_message: "好了，解决了！谢谢".to_string(),
            tool_call_count: 0,
            conversation_messages: vec![],
            pain_confidence: None,
            industry_keywords: vec![],
        };
        let signals = evaluate_triggers(&ctx);
        assert!(signals.contains(&TriggerSignal::PositiveFeedback));
    }

    #[test]
    fn test_complex_tool_chain_trigger() {
        let ctx = TriggerContext {
            user_message: "帮我处理一下".to_string(),
            tool_call_count: 4,
            conversation_messages: vec![],
            pain_confidence: None,
            industry_keywords: vec![],
        };
        let signals = evaluate_triggers(&ctx);
        assert!(signals.contains(&TriggerSignal::ComplexToolChain));
    }

    #[test]
    fn test_user_correction_trigger() {
        let ctx = TriggerContext {
            user_message: "不对，应该是另一个方案".to_string(),
            tool_call_count: 0,
            conversation_messages: vec![],
            pain_confidence: None,
            industry_keywords: vec![],
        };
        let signals = evaluate_triggers(&ctx);
        assert!(signals.contains(&TriggerSignal::UserCorrection));
    }

    #[test]
    fn test_industry_pattern_trigger() {
        let ctx = TriggerContext {
            user_message: "库存又不够了".to_string(),
            tool_call_count: 0,
            conversation_messages: vec![
                "帮我查库存".into(),
                "库存数据怎么看".into(),
                "库存预警设置".into(),
                "库存又不够了".into(),
            ],
            pain_confidence: None,
            industry_keywords: vec!["库存".to_string(), "SKU".to_string(), "GMV".to_string()],
        };
        let signals = evaluate_triggers(&ctx);
        assert!(signals.contains(&TriggerSignal::IndustryPattern));
    }

    #[test]
    fn test_no_trigger() {
        let ctx = TriggerContext {
            user_message: "今天天气怎么样".to_string(),
            tool_call_count: 0,
            conversation_messages: vec![],
            pain_confidence: None,
            industry_keywords: vec![],
        };
        let signals = evaluate_triggers(&ctx);
        assert!(signals.is_empty());
    }

    #[test]
    fn test_multiple_triggers() {
        let ctx = TriggerContext {
            user_message: "不对，帮我重新做一下库存报表".to_string(),
            tool_call_count: 3,
            conversation_messages: vec![
                "库存报表".into(),
                "帮我做库存报表".into(),
                "库存报表数据".into(),
                "不对，帮我重新做一下库存报表".into(),
            ],
            pain_confidence: Some(0.8),
            industry_keywords: vec!["库存".to_string()],
        };
        let signals = evaluate_triggers(&ctx);
        assert!(signals.contains(&TriggerSignal::PainConfirmed));
        assert!(signals.contains(&TriggerSignal::ComplexToolChain));
        assert!(signals.contains(&TriggerSignal::UserCorrection));
        assert!(signals.contains(&TriggerSignal::IndustryPattern));
        assert!(signals.len() >= 3);
    }
}