use mongodb::bson::doc;
use rmcp::{model::*, ErrorData as McpError};
use schemars::JsonSchema;
use serde::Deserialize;

use crate::database::Database;

const MAX_LIMIT: i64 = 200;
const DEFAULT_LIMIT: i64 = 50;

fn cap_limit(limit: Option<i64>) -> i64 {
    limit.unwrap_or(DEFAULT_LIMIT).clamp(1, MAX_LIMIT)
}

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

    #[test]
    fn cap_limit_default() {
        assert_eq!(cap_limit(None), DEFAULT_LIMIT);
    }

    #[test]
    fn cap_limit_clamps_high() {
        assert_eq!(cap_limit(Some(300)), MAX_LIMIT);
    }

    #[test]
    fn cap_limit_clamps_low() {
        assert_eq!(cap_limit(Some(0)), 1);
    }

    #[test]
    fn list_dast_findings_params_deserialize() {
        let json = serde_json::json!({
            "target_id": "t1",
            "scan_run_id": "sr1",
            "severity": "critical",
            "exploitable": true,
            "vuln_type": "sql_injection",
            "limit": 10
        });
        let params: ListDastFindingsParams = serde_json::from_value(json).unwrap();
        assert_eq!(params.target_id.as_deref(), Some("t1"));
        assert_eq!(params.scan_run_id.as_deref(), Some("sr1"));
        assert_eq!(params.severity.as_deref(), Some("critical"));
        assert_eq!(params.exploitable, Some(true));
        assert_eq!(params.vuln_type.as_deref(), Some("sql_injection"));
        assert_eq!(params.limit, Some(10));
    }

    #[test]
    fn list_dast_findings_params_all_optional() {
        let params: ListDastFindingsParams = serde_json::from_value(serde_json::json!({})).unwrap();
        assert!(params.target_id.is_none());
        assert!(params.scan_run_id.is_none());
        assert!(params.severity.is_none());
        assert!(params.exploitable.is_none());
        assert!(params.vuln_type.is_none());
        assert!(params.limit.is_none());
    }

    #[test]
    fn dast_scan_summary_params_deserialize() {
        let params: DastScanSummaryParams =
            serde_json::from_value(serde_json::json!({ "target_id": "abc" })).unwrap();
        assert_eq!(params.target_id.as_deref(), Some("abc"));

        let params2: DastScanSummaryParams = serde_json::from_value(serde_json::json!({})).unwrap();
        assert!(params2.target_id.is_none());
    }
}

#[derive(Debug, Deserialize, JsonSchema)]
pub struct ListDastFindingsParams {
    /// Filter by DAST target ID
    pub target_id: Option<String>,
    /// Filter by scan run ID
    pub scan_run_id: Option<String>,
    /// Filter by severity: info, low, medium, high, critical
    pub severity: Option<String>,
    /// Only show confirmed exploitable findings
    pub exploitable: Option<bool>,
    /// Filter by vulnerability type (e.g. sql_injection, xss, ssrf)
    pub vuln_type: Option<String>,
    /// Maximum number of results (default 50, max 200)
    pub limit: Option<i64>,
}

pub async fn list_dast_findings(
    db: &Database,
    params: ListDastFindingsParams,
) -> Result<CallToolResult, McpError> {
    let mut filter = doc! {};
    if let Some(ref target_id) = params.target_id {
        filter.insert("target_id", target_id);
    }
    if let Some(ref scan_run_id) = params.scan_run_id {
        filter.insert("scan_run_id", scan_run_id);
    }
    if let Some(ref severity) = params.severity {
        filter.insert("severity", severity);
    }
    if let Some(exploitable) = params.exploitable {
        filter.insert("exploitable", exploitable);
    }
    if let Some(ref vuln_type) = params.vuln_type {
        filter.insert("vuln_type", vuln_type);
    }

    let limit = cap_limit(params.limit);

    let mut cursor = db
        .dast_findings()
        .find(filter)
        .sort(doc! { "created_at": -1 })
        .limit(limit)
        .await
        .map_err(|e| McpError::internal_error(format!("DB error: {e}"), None))?;

    let mut results = Vec::new();
    while cursor
        .advance()
        .await
        .map_err(|e| McpError::internal_error(format!("cursor error: {e}"), None))?
    {
        let finding = cursor
            .deserialize_current()
            .map_err(|e| McpError::internal_error(format!("deserialize error: {e}"), None))?;
        results.push(finding);
    }

    let json = serde_json::to_string_pretty(&results)
        .map_err(|e| McpError::internal_error(format!("json error: {e}"), None))?;

    Ok(CallToolResult::success(vec![Content::text(json)]))
}

#[derive(Debug, Deserialize, JsonSchema)]
pub struct DastScanSummaryParams {
    /// Filter by DAST target ID
    pub target_id: Option<String>,
}

pub async fn dast_scan_summary(
    db: &Database,
    params: DastScanSummaryParams,
) -> Result<CallToolResult, McpError> {
    let mut filter = doc! {};
    if let Some(ref target_id) = params.target_id {
        filter.insert("target_id", target_id);
    }

    // Get recent scan runs
    let mut cursor = db
        .dast_scan_runs()
        .find(filter.clone())
        .sort(doc! { "started_at": -1 })
        .limit(10)
        .await
        .map_err(|e| McpError::internal_error(format!("DB error: {e}"), None))?;

    let mut scan_runs = Vec::new();
    while cursor
        .advance()
        .await
        .map_err(|e| McpError::internal_error(format!("cursor error: {e}"), None))?
    {
        let run = cursor
            .deserialize_current()
            .map_err(|e| McpError::internal_error(format!("deserialize error: {e}"), None))?;
        scan_runs.push(serde_json::json!({
            "id": run.id.map(|id| id.to_hex()),
            "target_id": run.target_id,
            "status": run.status,
            "findings_count": run.findings_count,
            "exploitable_count": run.exploitable_count,
            "endpoints_discovered": run.endpoints_discovered,
            "started_at": run.started_at.to_rfc3339(),
            "completed_at": run.completed_at.map(|t| t.to_rfc3339()),
        }));
    }

    // Count findings by severity
    let mut findings_filter = doc! {};
    if let Some(ref target_id) = params.target_id {
        findings_filter.insert("target_id", target_id);
    }
    let total_findings = db
        .dast_findings()
        .count_documents(findings_filter.clone())
        .await
        .map_err(|e| McpError::internal_error(format!("DB error: {e}"), None))?;

    let mut exploitable_filter = findings_filter.clone();
    exploitable_filter.insert("exploitable", true);
    let exploitable_count = db
        .dast_findings()
        .count_documents(exploitable_filter)
        .await
        .map_err(|e| McpError::internal_error(format!("DB error: {e}"), None))?;

    let summary = serde_json::json!({
        "total_findings": total_findings,
        "exploitable_findings": exploitable_count,
        "recent_scan_runs": scan_runs,
    });

    let json = serde_json::to_string_pretty(&summary)
        .map_err(|e| McpError::internal_error(format!("json error: {e}"), None))?;

    Ok(CallToolResult::success(vec![Content::text(json)]))
}