use std::path::Path;

use compliance_core::models::{SbomEntry, ScanType, VulnRef};
use compliance_core::traits::{ScanOutput, Scanner};
use compliance_core::CoreError;

pub struct SbomScanner;

impl Scanner for SbomScanner {
    fn name(&self) -> &str {
        "sbom"
    }

    fn scan_type(&self) -> ScanType {
        ScanType::Sbom
    }

    async fn scan(&self, repo_path: &Path, repo_id: &str) -> Result<ScanOutput, CoreError> {
        let mut entries = Vec::new();

        // Run syft for SBOM generation
        match run_syft(repo_path, repo_id).await {
            Ok(syft_entries) => entries.extend(syft_entries),
            Err(e) => tracing::warn!("syft failed: {e}"),
        }

        // Run cargo-audit for Rust-specific vulns
        match run_cargo_audit(repo_path, repo_id).await {
            Ok(vulns) => merge_audit_vulns(&mut entries, vulns),
            Err(e) => tracing::warn!("cargo-audit skipped: {e}"),
        }

        Ok(ScanOutput {
            findings: Vec::new(),
            sbom_entries: entries,
        })
    }
}

async fn run_syft(repo_path: &Path, repo_id: &str) -> Result<Vec<SbomEntry>, CoreError> {
    let output = tokio::process::Command::new("syft")
        .arg(repo_path)
        .args(["-o", "cyclonedx-json"])
        .output()
        .await
        .map_err(|e| CoreError::Scanner {
            scanner: "syft".to_string(),
            source: Box::new(e),
        })?;

    if !output.status.success() {
        let stderr = String::from_utf8_lossy(&output.stderr);
        return Err(CoreError::Scanner {
            scanner: "syft".to_string(),
            source: format!("syft exited with {}: {stderr}", output.status).into(),
        });
    }

    let cdx: CycloneDxBom = serde_json::from_slice(&output.stdout)?;
    let entries = cdx
        .components
        .unwrap_or_default()
        .into_iter()
        .map(|c| {
            let mut entry = SbomEntry::new(
                repo_id.to_string(),
                c.name,
                c.version.unwrap_or_else(|| "unknown".to_string()),
                c.component_type.unwrap_or_else(|| "library".to_string()),
            );
            entry.purl = c.purl;
            entry.license = c.licenses.and_then(|ls| {
                ls.first().and_then(|l| {
                    l.license.as_ref().map(|lic| {
                        lic.id
                            .clone()
                            .unwrap_or_else(|| lic.name.clone().unwrap_or_default())
                    })
                })
            });
            entry
        })
        .collect();

    Ok(entries)
}

async fn run_cargo_audit(repo_path: &Path, _repo_id: &str) -> Result<Vec<AuditVuln>, CoreError> {
    let cargo_lock = repo_path.join("Cargo.lock");
    if !cargo_lock.exists() {
        return Ok(Vec::new());
    }

    let output = tokio::process::Command::new("cargo")
        .args(["audit", "--json"])
        .current_dir(repo_path)
        .output()
        .await
        .map_err(|e| CoreError::Scanner {
            scanner: "cargo-audit".to_string(),
            source: Box::new(e),
        })?;

    let result: CargoAuditOutput =
        serde_json::from_slice(&output.stdout).unwrap_or_else(|_| CargoAuditOutput {
            vulnerabilities: CargoAuditVulns { list: Vec::new() },
        });

    let vulns = result
        .vulnerabilities
        .list
        .into_iter()
        .map(|v| AuditVuln {
            package: v.advisory.package,
            id: v.advisory.id,
            url: v.advisory.url,
        })
        .collect();

    Ok(vulns)
}

fn merge_audit_vulns(entries: &mut [SbomEntry], vulns: Vec<AuditVuln>) {
    for vuln in vulns {
        if let Some(entry) = entries.iter_mut().find(|e| e.name == vuln.package) {
            entry.known_vulnerabilities.push(VulnRef {
                id: vuln.id.clone(),
                source: "cargo-audit".to_string(),
                severity: None,
                url: Some(vuln.url),
            });
        }
    }
}

// CycloneDX JSON types
#[derive(serde::Deserialize)]
struct CycloneDxBom {
    components: Option<Vec<CdxComponent>>,
}

#[derive(serde::Deserialize)]
struct CdxComponent {
    name: String,
    version: Option<String>,
    #[serde(rename = "type")]
    component_type: Option<String>,
    purl: Option<String>,
    licenses: Option<Vec<CdxLicenseWrapper>>,
}

#[derive(serde::Deserialize)]
struct CdxLicenseWrapper {
    license: Option<CdxLicense>,
}

#[derive(serde::Deserialize)]
struct CdxLicense {
    id: Option<String>,
    name: Option<String>,
}

// Cargo audit types
#[derive(serde::Deserialize)]
struct CargoAuditOutput {
    vulnerabilities: CargoAuditVulns,
}

#[derive(serde::Deserialize)]
struct CargoAuditVulns {
    list: Vec<CargoAuditEntry>,
}

#[derive(serde::Deserialize)]
struct CargoAuditEntry {
    advisory: CargoAuditAdvisory,
}

#[derive(serde::Deserialize)]
struct CargoAuditAdvisory {
    id: String,
    package: String,
    url: String,
}

struct AuditVuln {
    package: String,
    id: String,
    url: String,
}