use std::sync::Arc;

use mongodb::bson::doc;
use tracing::Instrument;

use compliance_core::models::*;
use compliance_core::traits::Scanner;
use compliance_core::AgentConfig;

use crate::database::Database;
use crate::error::AgentError;
use crate::llm::LlmClient;
use crate::pipeline::cve::CveScanner;
use crate::pipeline::git::GitOps;
use crate::pipeline::gitleaks::GitleaksScanner;
use crate::pipeline::lint::LintScanner;
use crate::pipeline::patterns::{GdprPatternScanner, OAuthPatternScanner};
use crate::pipeline::sbom::SbomScanner;
use crate::pipeline::semgrep::SemgrepScanner;

/// Context from graph analysis passed to LLM triage for enhanced filtering
#[derive(Debug)]
#[allow(dead_code)]
pub struct GraphContext {
    pub node_count: u32,
    pub edge_count: u32,
    pub community_count: u32,
    pub impacts: Vec<compliance_core::models::graph::ImpactAnalysis>,
}

pub struct PipelineOrchestrator {
    pub(super) config: AgentConfig,
    pub(super) db: Database,
    pub(super) llm: Arc<LlmClient>,
    pub(super) http: reqwest::Client,
}

impl PipelineOrchestrator {
    pub fn new(
        config: AgentConfig,
        db: Database,
        llm: Arc<LlmClient>,
        http: reqwest::Client,
    ) -> Self {
        Self {
            config,
            db,
            llm,
            http,
        }
    }

    #[tracing::instrument(skip_all, fields(repo_id = %repo_id, trigger = ?trigger))]
    pub async fn run(&self, repo_id: &str, trigger: ScanTrigger) -> Result<(), AgentError> {
        // Look up the repository
        let repo = self
            .db
            .repositories()
            .find_one(doc! { "_id": mongodb::bson::oid::ObjectId::parse_str(repo_id).map_err(|e| AgentError::Other(e.to_string()))? })
            .await?
            .ok_or_else(|| AgentError::Other(format!("Repository {repo_id} not found")))?;

        // Create scan run
        let scan_run = ScanRun::new(repo_id.to_string(), trigger);
        let insert = self.db.scan_runs().insert_one(&scan_run).await?;
        let scan_run_id = insert
            .inserted_id
            .as_object_id()
            .map(|id| id.to_hex())
            .unwrap_or_default();

        let result = self.run_pipeline(&repo, &scan_run_id).await;

        // Update scan run status
        match &result {
            Ok(count) => {
                self.db
                    .scan_runs()
                    .update_one(
                        doc! { "_id": &insert.inserted_id },
                        doc! {
                            "$set": {
                                "status": "completed",
                                "current_phase": "completed",
                                "new_findings_count": *count as i64,
                                "completed_at": mongodb::bson::DateTime::now(),
                            }
                        },
                    )
                    .await?;
            }
            Err(e) => {
                tracing::error!(repo_id, error = %e, "Scan pipeline failed");
                self.db
                    .scan_runs()
                    .update_one(
                        doc! { "_id": &insert.inserted_id },
                        doc! {
                            "$set": {
                                "status": "failed",
                                "error_message": e.to_string(),
                                "completed_at": mongodb::bson::DateTime::now(),
                            }
                        },
                    )
                    .await?;
            }
        }

        result.map(|_| ())
    }

    #[tracing::instrument(skip_all, fields(repo_id = repo.name.as_str()))]
    async fn run_pipeline(
        &self,
        repo: &TrackedRepository,
        scan_run_id: &str,
    ) -> Result<u32, AgentError> {
        let repo_id = repo.id.as_ref().map(|id| id.to_hex()).unwrap_or_default();

        // Stage 0: Change detection
        tracing::info!("[{repo_id}] Stage 0: Change detection");
        let creds = GitOps::make_repo_credentials(&self.config, repo);
        let git_ops = GitOps::new(&self.config.git_clone_base_path, creds);
        let repo_path = git_ops.clone_or_fetch(&repo.git_url, &repo.name)?;

        if !GitOps::has_new_commits(&repo_path, repo.last_scanned_commit.as_deref())? {
            tracing::info!("[{repo_id}] No new commits, skipping scan");
            return Ok(0);
        }

        let current_sha = GitOps::get_head_sha(&repo_path)?;
        let mut all_findings: Vec<Finding> = Vec::new();

        // Stage 1: Semgrep SAST
        tracing::info!("[{repo_id}] Stage 1: Semgrep SAST");
        self.update_phase(scan_run_id, "sast").await;
        match async {
            let semgrep = SemgrepScanner;
            semgrep.scan(&repo_path, &repo_id).await
        }
        .instrument(tracing::info_span!("stage_sast"))
        .await
        {
            Ok(output) => all_findings.extend(output.findings),
            Err(e) => tracing::warn!("[{repo_id}] Semgrep failed: {e}"),
        }

        // Stage 2: SBOM Generation
        tracing::info!("[{repo_id}] Stage 2: SBOM Generation");
        self.update_phase(scan_run_id, "sbom_generation").await;
        let mut sbom_entries = match async {
            let sbom_scanner = SbomScanner;
            sbom_scanner.scan(&repo_path, &repo_id).await
        }
        .instrument(tracing::info_span!("stage_sbom_generation"))
        .await
        {
            Ok(output) => output.sbom_entries,
            Err(e) => {
                tracing::warn!("[{repo_id}] SBOM generation failed: {e}");
                Vec::new()
            }
        };

        // Stage 3: CVE Scanning
        tracing::info!("[{repo_id}] Stage 3: CVE Scanning");
        self.update_phase(scan_run_id, "cve_scanning").await;
        let cve_scanner = CveScanner::new(
            self.http.clone(),
            self.config.searxng_url.clone(),
            self.config.nvd_api_key.as_ref().map(|k| {
                use secrecy::ExposeSecret;
                k.expose_secret().to_string()
            }),
        );
        let cve_alerts = match async {
            cve_scanner
                .scan_dependencies(&repo_id, &mut sbom_entries)
                .await
        }
        .instrument(tracing::info_span!("stage_cve_scanning"))
        .await
        {
            Ok(alerts) => alerts,
            Err(e) => {
                tracing::warn!("[{repo_id}] CVE scanning failed: {e}");
                Vec::new()
            }
        };

        // Stage 4: Pattern Scanning (GDPR + OAuth)
        tracing::info!("[{repo_id}] Stage 4: Pattern Scanning");
        self.update_phase(scan_run_id, "pattern_scanning").await;
        {
            let pattern_findings = async {
                let mut findings = Vec::new();
                let gdpr = GdprPatternScanner::new();
                match gdpr.scan(&repo_path, &repo_id).await {
                    Ok(output) => findings.extend(output.findings),
                    Err(e) => tracing::warn!("[{repo_id}] GDPR pattern scan failed: {e}"),
                }
                let oauth = OAuthPatternScanner::new();
                match oauth.scan(&repo_path, &repo_id).await {
                    Ok(output) => findings.extend(output.findings),
                    Err(e) => tracing::warn!("[{repo_id}] OAuth pattern scan failed: {e}"),
                }
                findings
            }
            .instrument(tracing::info_span!("stage_pattern_scanning"))
            .await;
            all_findings.extend(pattern_findings);
        }

        // Stage 4a: Secret Detection (Gitleaks)
        tracing::info!("[{repo_id}] Stage 4a: Secret Detection");
        self.update_phase(scan_run_id, "secret_detection").await;
        match async {
            let gitleaks = GitleaksScanner;
            gitleaks.scan(&repo_path, &repo_id).await
        }
        .instrument(tracing::info_span!("stage_secret_detection"))
        .await
        {
            Ok(output) => all_findings.extend(output.findings),
            Err(e) => tracing::warn!("[{repo_id}] Gitleaks failed: {e}"),
        }

        // Stage 4b: Lint Scanning
        tracing::info!("[{repo_id}] Stage 4b: Lint Scanning");
        self.update_phase(scan_run_id, "lint_scanning").await;
        match async {
            let lint = LintScanner;
            lint.scan(&repo_path, &repo_id).await
        }
        .instrument(tracing::info_span!("stage_lint_scanning"))
        .await
        {
            Ok(output) => all_findings.extend(output.findings),
            Err(e) => tracing::warn!("[{repo_id}] Lint scanning failed: {e}"),
        }

        // Stage 4.5: Graph Building
        tracing::info!("[{repo_id}] Stage 4.5: Graph Building");
        self.update_phase(scan_run_id, "graph_building").await;
        let graph_context = match async {
            self.build_code_graph(&repo_path, &repo_id, &all_findings)
                .await
        }
        .instrument(tracing::info_span!("stage_graph_building"))
        .await
        {
            Ok(ctx) => Some(ctx),
            Err(e) => {
                tracing::warn!("[{repo_id}] Graph building failed: {e}");
                None
            }
        };

        // Stage 5: LLM Triage (enhanced with graph context)
        tracing::info!(
            "[{repo_id}] Stage 5: LLM Triage ({} findings)",
            all_findings.len()
        );
        self.update_phase(scan_run_id, "llm_triage").await;
        let triaged = crate::llm::triage::triage_findings(
            &self.llm,
            &mut all_findings,
            graph_context.as_ref(),
        )
        .await;
        tracing::info!("[{repo_id}] Triaged: {triaged} findings passed confidence threshold");

        // Dedup against existing findings and insert new ones
        let mut new_count = 0u32;
        let mut new_findings: Vec<Finding> = Vec::new();
        for mut finding in all_findings {
            finding.scan_run_id = Some(scan_run_id.to_string());
            // Check if fingerprint already exists
            let existing = self
                .db
                .findings()
                .find_one(doc! { "fingerprint": &finding.fingerprint })
                .await?;
            if existing.is_none() {
                let result = self.db.findings().insert_one(&finding).await?;
                finding.id = result.inserted_id.as_object_id();
                new_findings.push(finding);
                new_count += 1;
            }
        }

        // Remove stale SBOM entries for this repo before reinserting
        if !sbom_entries.is_empty() {
            self.db
                .sbom_entries()
                .delete_many(doc! { "repo_id": &repo.id })
                .await?;
        }

        // Persist SBOM entries
        for entry in &sbom_entries {
            let filter = doc! {
                "repo_id": &entry.repo_id,
                "name": &entry.name,
                "version": &entry.version,
            };
            let update = mongodb::bson::to_document(entry)
                .map(|d| doc! { "$set": d })
                .unwrap_or_else(|_| doc! {});
            self.db
                .sbom_entries()
                .update_one(filter, update)
                .upsert(true)
                .await?;
        }

        // Persist CVE alerts (upsert by cve_id + repo_id)
        for alert in &cve_alerts {
            let filter = doc! {
                "cve_id": &alert.cve_id,
                "repo_id": &alert.repo_id,
            };
            let update = mongodb::bson::to_document(alert)
                .map(|d| doc! { "$set": d })
                .unwrap_or_else(|_| doc! {});
            self.db
                .cve_alerts()
                .update_one(filter, update)
                .upsert(true)
                .await?;
        }

        // Stage 6: Issue Creation
        tracing::info!("[{repo_id}] Stage 6: Issue Creation");
        self.update_phase(scan_run_id, "issue_creation").await;
        if let Err(e) = self
            .create_tracker_issues(repo, &repo_id, &new_findings)
            .await
        {
            tracing::warn!("[{repo_id}] Issue creation failed: {e}");
        }

        // Stage 7: Update repository
        self.db
            .repositories()
            .update_one(
                doc! { "_id": repo.id },
                doc! {
                    "$set": {
                        "last_scanned_commit": &current_sha,
                        "updated_at": mongodb::bson::DateTime::now(),
                    },
                    "$inc": { "findings_count": new_count as i64 },
                },
            )
            .await?;

        // Stage 8: DAST (async, optional — only if a DastTarget is configured)
        tracing::info!("[{repo_id}] Stage 8: Checking for DAST targets");
        self.update_phase(scan_run_id, "dast_scanning").await;
        self.maybe_trigger_dast(&repo_id, scan_run_id).await;

        tracing::info!("[{repo_id}] Scan complete: {new_count} new findings");
        Ok(new_count)
    }

    pub(super) async fn update_phase(&self, scan_run_id: &str, phase: &str) {
        if let Ok(oid) = mongodb::bson::oid::ObjectId::parse_str(scan_run_id) {
            let _ = self
                .db
                .scan_runs()
                .update_one(
                    doc! { "_id": oid },
                    doc! {
                        "$set": { "current_phase": phase },
                        "$push": { "phases_completed": phase },
                    },
                )
                .await;
        }
    }
}

/// Extract the scheme + host from a git URL.
/// e.g. "https://gitea.example.com/owner/repo.git" -> "https://gitea.example.com"
/// e.g. "ssh://git@gitea.example.com:22/owner/repo.git" -> "https://gitea.example.com"
pub(super) fn extract_base_url(git_url: &str) -> Option<String> {
    if let Some(rest) = git_url.strip_prefix("https://") {
        let host = rest.split('/').next()?;
        Some(format!("https://{host}"))
    } else if let Some(rest) = git_url.strip_prefix("http://") {
        let host = rest.split('/').next()?;
        Some(format!("http://{host}"))
    } else if let Some(rest) = git_url.strip_prefix("ssh://") {
        // ssh://git@host:port/path -> extract host
        let after_at = rest.find('@').map(|i| &rest[i + 1..]).unwrap_or(rest);
        let host = after_at.split(&[':', '/'][..]).next()?;
        Some(format!("https://{host}"))
    } else if let Some(at_pos) = git_url.find('@') {
        // SCP-style: git@host:owner/repo.git
        let after_at = &git_url[at_pos + 1..];
        let host = after_at.split(':').next()?;
        Some(format!("https://{host}"))
    } else {
        None
    }
}