use serde::{Deserialize, Serialize};

// === 分析请求 ===

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct AnalyzeRequest {
    pub analysis_type: AnalysisType,
    pub source_ref: String,
    pub options: AnalyzeOptions,
}

#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
#[serde(rename_all = "snake_case")]
pub enum AnalysisType {
    LabReport,
    Trends,
    CheckupPlan,
    ReportSummary,
}

impl AnalysisType {
    pub fn as_str(&self) -> &str {
        match self {
            Self::LabReport => "lab_report",
            Self::Trends => "trend",
            Self::CheckupPlan => "checkup_plan",
            Self::ReportSummary => "report_summary",
        }
    }

    pub fn prompt_name(&self) -> &str {
        match self {
            Self::LabReport => "lab_report_interpretation",
            Self::Trends => "health_trend_analysis",
            Self::CheckupPlan => "personalized_checkup_plan",
            Self::ReportSummary => "report_summary_generation",
        }
    }
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct AnalyzeOptions {
    pub detail_level: Option<String>,
    pub language: Option<String>,
}

impl Default for AnalyzeOptions {
    fn default() -> Self {
        Self {
            detail_level: Some("patient_friendly".into()),
            language: Some("zh-CN".into()),
        }
    }
}

// === AI Provider 请求/响应 ===

#[derive(Debug, Clone)]
pub struct GenerateRequest {
    pub system_prompt: String,
    pub user_prompt: String,
    pub model: String,
    pub temperature: f32,
    pub max_tokens: u32,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct GenerateResponse {
    pub content: String,
    pub model: String,
    pub input_tokens: u32,
    pub output_tokens: u32,
    pub duration_ms: u64,
}

// === SSE 事件 ===

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct TokenUsage {
    pub input: u32,
    pub output: u32,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(tag = "type")]
pub enum AnalysisSseEvent {
    #[serde(rename = "chunk")]
    Chunk { content: String, index: u32 },
    #[serde(rename = "metadata")]
    Metadata {
        model: String,
        tokens: TokenUsage,
        duration_ms: u64,
    },
    #[serde(rename = "done")]
    Done {
        analysis_id: uuid::Uuid,
        status: String,
    },
    #[serde(rename = "error")]
    Error { message: String },
}

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

    // ---- AnalysisType::as_str ----

    #[test]
    fn analysis_type_as_str() {
        assert_eq!(AnalysisType::LabReport.as_str(), "lab_report");
        assert_eq!(AnalysisType::Trends.as_str(), "trend");
        assert_eq!(AnalysisType::CheckupPlan.as_str(), "checkup_plan");
        assert_eq!(AnalysisType::ReportSummary.as_str(), "report_summary");
    }

    // ---- AnalysisType::prompt_name ----

    #[test]
    fn analysis_type_prompt_name() {
        assert_eq!(AnalysisType::LabReport.prompt_name(), "lab_report_interpretation");
        assert_eq!(AnalysisType::Trends.prompt_name(), "health_trend_analysis");
        assert_eq!(AnalysisType::CheckupPlan.prompt_name(), "personalized_checkup_plan");
        assert_eq!(AnalysisType::ReportSummary.prompt_name(), "report_summary_generation");
    }

    // ---- AnalysisType serde round-trip ----

    #[test]
    fn analysis_type_serde_roundtrip() {
        let types = vec![
            AnalysisType::LabReport,
            AnalysisType::Trends,
            AnalysisType::CheckupPlan,
            AnalysisType::ReportSummary,
        ];
        for t in types {
            let json = serde_json::to_string(&t).unwrap();
            let back: AnalysisType = serde_json::from_str(&json).unwrap();
            assert_eq!(t, back);
        }
    }

    #[test]
    fn analysis_type_deserialize_snake_case() {
        let t: AnalysisType = serde_json::from_str("\"lab_report\"").unwrap();
        assert_eq!(t, AnalysisType::LabReport);

        let t: AnalysisType = serde_json::from_str("\"trends\"").unwrap();
        assert_eq!(t, AnalysisType::Trends);
    }

    // ---- AnalyzeOptions::default ----

    #[test]
    fn analyze_options_default() {
        let opts = AnalyzeOptions::default();
        assert_eq!(opts.detail_level, Some("patient_friendly".to_string()));
        assert_eq!(opts.language, Some("zh-CN".to_string()));
    }

    // ---- AnalysisSseEvent serde round-trip ----

    #[test]
    fn sse_event_chunk_roundtrip() {
        let event = AnalysisSseEvent::Chunk {
            content: "血红蛋白偏低".to_string(),
            index: 0,
        };
        let json = serde_json::to_string(&event).unwrap();
        assert!(json.contains("\"type\":\"chunk\""));
        let back: AnalysisSseEvent = serde_json::from_str(&json).unwrap();
        match back {
            AnalysisSseEvent::Chunk { content, index } => {
                assert_eq!(content, "血红蛋白偏低");
                assert_eq!(index, 0);
            }
            _ => panic!("期望 Chunk 变体"),
        }
    }

    #[test]
    fn sse_event_done_roundtrip() {
        let id = {
            let ts = uuid::Timestamp::now(uuid::NoContext);
            uuid::Uuid::new_v7(ts)
        };
        let event = AnalysisSseEvent::Done {
            analysis_id: id,
            status: "completed".to_string(),
        };
        let json = serde_json::to_string(&event).unwrap();
        let back: AnalysisSseEvent = serde_json::from_str(&json).unwrap();
        match back {
            AnalysisSseEvent::Done { analysis_id, status } => {
                assert_eq!(analysis_id, id);
                assert_eq!(status, "completed");
            }
            _ => panic!("期望 Done 变体"),
        }
    }

    #[test]
    fn sse_event_error_roundtrip() {
        let event = AnalysisSseEvent::Error {
            message: "超时".to_string(),
        };
        let json = serde_json::to_string(&event).unwrap();
        assert!(json.contains("\"type\":\"error\""));
        let back: AnalysisSseEvent = serde_json::from_str(&json).unwrap();
        match back {
            AnalysisSseEvent::Error { message } => assert_eq!(message, "超时"),
            _ => panic!("期望 Error 变体"),
        }
    }
}