repotoire 0.9.0

//! Wildcard Imports Detector
//!
//! Graph-enhanced detection of wildcard imports.
//! Uses graph to:
//! - Check what's actually imported from the module (via import edges)
//! - Suggest specific imports based on actual usage

use crate::detectors::base::{Detector, DetectorConfig};
use crate::graph::GraphQueryExt;
use crate::models::{deterministic_finding_id, Finding, Severity};
use anyhow::Result;
use regex::Regex;
use std::collections::HashSet;
use std::path::PathBuf;
use std::sync::LazyLock;
use tracing::info;

static WILDCARD_PATTERN: LazyLock<Regex> = LazyLock::new(|| {
    Regex::new(r"(?i)(from\s+\S+\s+import\s+\*|import\s+\*\s+from|import\s+\*\s*;|\.\*;)")
        .expect("valid regex")
});
static MODULE_NAME: LazyLock<Regex> = LazyLock::new(|| {
    Regex::new(r#"from\s+(\S+)\s+import|import\s+\*\s+from\s+['"]([^'"]+)"#).expect("valid regex")
});

pub struct WildcardImportsDetector {
    #[allow(dead_code)] // Part of detector pattern, used for file scanning
    repository_path: PathBuf,
    max_findings: usize,
}

impl WildcardImportsDetector {
    crate::detectors::detector_new!(100);

    /// Extract module name from wildcard import line
    fn extract_module_name(line: &str) -> Option<String> {
        MODULE_NAME
            .captures(line)
            .and_then(|caps| caps.get(1).or(caps.get(2)).map(|m| m.as_str().to_string()))
    }

    /// Find what symbols from a module are actually used in the file.
    /// Uses a pre-built index to avoid O(N) full graph scans per call.
    fn find_used_symbols(
        content: &str,
        module: &str,
        all_functions: &[crate::graph::store_models::CodeNode],
    ) -> Vec<String> {
        // Filter to functions from this module
        let module_symbols: HashSet<&str> = all_functions
            .iter()
            .filter(|f| {
                f.path(crate::graph::interner::global_interner())
                    .contains(module)
                    || f.qn(crate::graph::interner::global_interner())
                        .starts_with(module)
            })
            .map(|f| f.node_name(crate::graph::interner::global_interner()))
            .collect();

        // Check which are used in the content
        module_symbols
            .into_iter()
            .filter(|sym| content.contains(sym))
            .take(10)
            .map(|s| s.to_string())
            .collect()
    }
}

impl Detector for WildcardImportsDetector {
    fn name(&self) -> &'static str {
        "wildcard-imports"
    }
    fn description(&self) -> &'static str {
        "Detects wildcard imports"
    }

    fn requires_graph(&self) -> bool {
        false
    }

    fn file_extensions(&self) -> &'static [&'static str] {
        &["py", "js", "ts", "jsx", "tsx", "java"]
    }

    fn content_requirements(&self) -> crate::detectors::detector_context::ContentFlags {
        crate::detectors::detector_context::ContentFlags::HAS_IMPORT
    }

    fn detect(
        &self,
        ctx: &crate::detectors::analysis_context::AnalysisContext,
    ) -> Result<Vec<Finding>> {
        let graph = ctx.graph;
        let files = &ctx.as_file_provider();
        let mut findings = vec![];

        // Pre-fetch all functions once — O(N) instead of O(N) per wildcard import
        let all_functions = graph.get_functions();

        for path in files.files_with_extensions(&["py", "js", "ts", "java"]) {
            if findings.len() >= self.max_findings {
                break;
            }

            if let Some(content) = files.content(path) {
                let lines: Vec<&str> = content.lines().collect();
                for (i, line) in lines.iter().enumerate() {
                    let prev_line = if i > 0 { Some(lines[i - 1]) } else { None };
                    if crate::detectors::is_line_suppressed(line, prev_line) {
                        continue;
                    }

                    if WILDCARD_PATTERN.is_match(line) {
                        // Skip relative wildcard imports in __init__.py -- standard re-export pattern
                        let is_init_py = path
                            .file_name()
                            .and_then(|n| n.to_str())
                            .map(|n| n == "__init__.py")
                            .unwrap_or(false);
                        if is_init_py {
                            // ALL wildcard imports in __init__.py are re-exports
                            // This is the standard Python convention for package namespaces
                            continue;
                        }

                        // Try to extract module name and find used symbols
                        let module_name = Self::extract_module_name(line);
                        let used_symbols = module_name
                            .as_ref()
                            .map(|m| Self::find_used_symbols(&content, m, &all_functions))
                            .unwrap_or_default();

                        let mut notes = Vec::new();
                        if !used_symbols.is_empty() {
                            notes.push(format!(
                                "📊 Actually used: {}",
                                used_symbols
                                    .iter()
                                    .take(5)
                                    .cloned()
                                    .collect::<Vec<_>>()
                                    .join(", ")
                            ));
                            if used_symbols.len() > 5 {
                                notes.push(format!("   ... and {} more", used_symbols.len() - 5));
                            }
                        }

                        let context_notes = if notes.is_empty() {
                            String::new()
                        } else {
                            format!("\n\n**Analysis:**\n{}", notes.join("\n"))
                        };

                        let suggestion = if !used_symbols.is_empty() {
                            let imports = used_symbols
                                .iter()
                                .take(10)
                                .cloned()
                                .collect::<Vec<_>>()
                                .join(", ");
                            if let Some(ref module) = module_name {
                                format!("Replace with explicit imports:\n```python\nfrom {} import {}\n```", 
                                       module, imports)
                            } else {
                                format!("Import only what's needed: {}", imports)
                            }
                        } else {
                            "Import specific names instead.".to_string()
                        };

                        findings.push(Finding {
                            id: String::new(),
                            detector: "WildcardImportsDetector".to_string(),
                            severity: Severity::Low,
                            title: format!(
                                "Wildcard import{}",
                                module_name
                                    .as_ref()
                                    .map(|m| format!(": {}", m))
                                    .unwrap_or_default()
                            ),
                            description: format!(
                                "Wildcard imports pollute namespace and hide dependencies.{}",
                                context_notes
                            ),
                            affected_files: vec![path.to_path_buf()],
                            line_start: Some((i + 1) as u32),
                            line_end: Some((i + 1) as u32),
                            suggested_fix: Some(suggestion),
                            estimated_effort: Some("5 minutes".to_string()),
                            category: Some("code-quality".to_string()),
                            cwe_id: None,
                            why_it_matters: Some(
                                "Makes code harder to understand and refactor. \
                                 Tools can't determine where names come from."
                                    .to_string(),
                            ),
                            ..Default::default()
                        });
                    }
                }
            }
        }

        info!(
            "WildcardImportsDetector found {} findings (graph-aware)",
            findings.len()
        );
        Ok(findings)
    }
}

impl crate::detectors::RegisteredDetector for WildcardImportsDetector {
    fn create(init: &crate::detectors::DetectorInit) -> std::sync::Arc<dyn Detector> {
        std::sync::Arc::new(Self::new(init.repo_path))
    }

    fn max_tier() -> crate::models::Tier {
        crate::models::Tier::Deep
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::graph::builder::GraphBuilder;

    #[test]
    fn test_detects_wildcard_import() {
        let store = GraphBuilder::new().freeze();
        let detector = WildcardImportsDetector::new("/mock/repo");
        let ctx = crate::detectors::analysis_context::AnalysisContext::test_with_mock_files(
            &store,
            vec![(
                "app.py",
                "from os.path import *\n\nresult = join(\"/tmp\", \"file.txt\")\n",
            )],
        );
        let findings = detector.detect(&ctx).expect("detection should succeed");
        assert!(
            !findings.is_empty(),
            "Should detect wildcard import. Found: {:?}",
            findings.iter().map(|f| &f.title).collect::<Vec<_>>()
        );
    }

    #[test]
    fn test_no_finding_for_explicit_import() {
        let store = GraphBuilder::new().freeze();
        let detector = WildcardImportsDetector::new("/mock/repo");
        let ctx = crate::detectors::analysis_context::AnalysisContext::test_with_mock_files(
            &store,
            vec![(
                "app.py",
                "from os.path import join, exists\n\nresult = join(\"/tmp\", \"file.txt\")\n",
            )],
        );
        let findings = detector.detect(&ctx).expect("detection should succeed");
        assert!(
            findings.is_empty(),
            "Should not flag explicit imports. Found: {:?}",
            findings.iter().map(|f| &f.title).collect::<Vec<_>>()
        );
    }

    #[test]
    fn test_no_finding_for_relative_import_in_init_py() {
        let store = GraphBuilder::new().freeze();
        let detector = WildcardImportsDetector::new("/mock/repo");
        let ctx = crate::detectors::analysis_context::AnalysisContext::test_with_mock_files(
            &store,
            vec![(
                "__init__.py",
                "from .models import *\nfrom .views import *\n",
            )],
        );
        let findings = detector.detect(&ctx).expect("detection should succeed");
        assert!(
            findings.is_empty(),
            "Should not flag relative wildcard imports in __init__.py (re-export pattern). Found: {:?}",
            findings.iter().map(|f| &f.title).collect::<Vec<_>>()
        );
    }

    #[test]
    fn test_no_finding_for_absolute_import_in_init_py() {
        let store = GraphBuilder::new().freeze();
        let detector = WildcardImportsDetector::new("/mock/repo");
        let ctx = crate::detectors::analysis_context::AnalysisContext::test_with_mock_files(
            &store,
            vec![(
                "__init__.py",
                "from django.db.models.fields import *\nfrom os.path import *\n",
            )],
        );
        let findings = detector.detect(&ctx).expect("detection should succeed");
        assert!(
            findings.is_empty(),
            "Should not flag ANY wildcard imports in __init__.py (all are re-exports). Found: {:?}",
            findings.iter().map(|f| &f.title).collect::<Vec<_>>()
        );
    }

    #[test]
    fn test_still_detects_wildcard_in_regular_file() {
        let store = GraphBuilder::new().freeze();
        let detector = WildcardImportsDetector::new("/mock/repo");
        let ctx = crate::detectors::analysis_context::AnalysisContext::test_with_mock_files(
            &store,
            vec![(
                "app.py",
                "from os.path import *\nresult = join('/tmp', 'file')\n",
            )],
        );
        let findings = detector.detect(&ctx).expect("detection should succeed");
        assert!(
            !findings.is_empty(),
            "Should still detect wildcard in regular files"
        );
    }
}