astmap-core 0.0.1

// Markdown export with optional file pattern filter and token budget.
// Approximate token counting: 1 token ≈ 4 characters.

use std::fmt::Write;

use crate::error::DbError;
use crate::model::DepType;
use crate::port::ExportStore;

const CHARS_PER_TOKEN: usize = 4;

pub fn export_markdown(
    db: &dyn ExportStore,
    file_pattern: Option<&str>,
    token_budget: Option<i64>,
) -> Result<String, DbError> {
    let files = db.list_files(file_pattern)?;
    let (file_count, symbol_count, dep_count) = db.stats()?;
    let max_chars = token_budget.map(|t| t as usize * CHARS_PER_TOKEN);

    let mut out = String::new();

    // Header
    writeln!(out, "# Code Structure Index")?;
    writeln!(out)?;
    writeln!(
        out,
        "**Files:** {} | **Symbols:** {} | **Dependencies:** {}",
        file_count, symbol_count, dep_count
    )?;
    writeln!(out)?;
    writeln!(out, "---")?;
    writeln!(out)?;

    for file in &files {
        // Budget check
        if let Some(max) = max_chars {
            if out.len() >= max {
                writeln!(out)?;
                writeln!(out, "---")?;
                writeln!(
                    out,
                    "*Output truncated at ~{} tokens.*",
                    out.len() / CHARS_PER_TOKEN
                )?;
                break;
            }
        }

        writeln!(out, "## `{}`", file.path)?;
        writeln!(out)?;

        // Top-level symbols
        let symbols = db.get_symbols_for_file(file.id)?;
        if symbols.is_empty() {
            writeln!(out, "*No symbols extracted.*")?;
            writeln!(out)?;
            continue;
        }

        for sym in &symbols {
            // Symbol header
            if let Some(sig) = &sym.signature {
                writeln!(
                    out,
                    "### {} `{}` (line {}-{})",
                    sym.kind, sym.name, sym.start_line, sym.end_line
                )?;
                writeln!(out)?;
                writeln!(out, "```{}", file.language)?;
                writeln!(out, "{}", sig)?;
                writeln!(out, "```")?;
            } else {
                writeln!(
                    out,
                    "### {} `{}` (line {}-{})",
                    sym.kind, sym.name, sym.start_line, sym.end_line
                )?;
            }
            writeln!(out)?;

            // Summary (if available)
            if let Some(summary) = &sym.summary {
                writeln!(out, "> {}", summary)?;
                writeln!(out)?;
            }

            // Children (methods, etc.)
            let children = db.get_children(sym.id)?;
            if !children.is_empty() {
                writeln!(out, "**Members:**")?;
                writeln!(out)?;
                for child in &children {
                    let sig_str = child.signature.as_deref().unwrap_or(&child.name);
                    writeln!(
                        out,
                        "- `{}` {} (line {})",
                        sig_str, child.kind, child.start_line
                    )?;
                }
                writeln!(out)?;
            }
        }

        // File-level dependencies
        let deps = db.get_deps_for_file(file.id)?;
        let imports: Vec<_> = deps
            .iter()
            .filter(|d| d.dep_type == DepType::Imports)
            .collect();
        if !imports.is_empty() {
            writeln!(out, "**Imports:**")?;
            writeln!(out)?;
            for dep in imports {
                let target = dep.raw_import.as_deref().unwrap_or("(unknown)");
                writeln!(out, "- `{}`", target)?;
            }
            writeln!(out)?;
        }

        writeln!(out, "---")?;
        writeln!(out)?;
    }

    Ok(out)
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::model::{Dependency, File, ParseStatus, Symbol, SymbolKind};
    use crate::DbError;

    // --- Mock ExportStore ---

    struct MockExportStore {
        files: Vec<File>,
        symbols: std::collections::HashMap<i64, Vec<Symbol>>,
        children: std::collections::HashMap<i64, Vec<Symbol>>,
        deps: std::collections::HashMap<i64, Vec<Dependency>>,
        stats: (i64, i64, i64),
    }

    impl MockExportStore {
        fn empty() -> Self {
            Self {
                files: vec![],
                symbols: std::collections::HashMap::new(),
                children: std::collections::HashMap::new(),
                deps: std::collections::HashMap::new(),
                stats: (0, 0, 0),
            }
        }
    }

    impl crate::SymbolLookup for MockExportStore {
        fn get_file_id(&self, _path: &str) -> Result<Option<i64>, DbError> {
            Ok(None)
        }
        fn get_symbol_by_id(&self, _id: i64) -> Result<Option<Symbol>, DbError> {
            Ok(None)
        }
        fn search_symbols_by_name(
            &self,
            _name: &str,
            _limit: i64,
        ) -> Result<Vec<crate::SymbolResult>, DbError> {
            Ok(vec![])
        }
        fn get_symbols_for_file(&self, file_id: i64) -> Result<Vec<Symbol>, DbError> {
            Ok(self.symbols.get(&file_id).cloned().unwrap_or_default())
        }
        fn get_children(&self, symbol_id: i64) -> Result<Vec<Symbol>, DbError> {
            Ok(self.children.get(&symbol_id).cloned().unwrap_or_default())
        }
        fn impact_analysis(
            &self,
            _id: i64,
            _depth: i64,
        ) -> Result<Vec<crate::ImpactEntry>, DbError> {
            Ok(vec![])
        }
        fn stats(&self) -> Result<(i64, i64, i64), DbError> {
            Ok(self.stats)
        }
    }

    impl ExportStore for MockExportStore {
        fn list_files(&self, _pattern: Option<&str>) -> Result<Vec<File>, DbError> {
            Ok(self.files.clone())
        }
        fn get_deps_for_file(&self, file_id: i64) -> Result<Vec<Dependency>, DbError> {
            Ok(self.deps.get(&file_id).cloned().unwrap_or_default())
        }
    }

    fn make_file(id: i64, path: &str, lang: &str) -> File {
        File {
            id,
            scan_id: 1,
            path: path.to_string(),
            language: lang.to_string(),
            size_bytes: 100,
            content_hash: "abc".to_string(),
            last_modified: 0,
            parse_status: ParseStatus::Ok,
        }
    }

    fn make_sym(
        id: i64,
        file_id: i64,
        name: &str,
        kind: SymbolKind,
        sig: Option<&str>,
        summary: Option<&str>,
    ) -> Symbol {
        Symbol {
            id,
            file_id,
            parent_id: None,
            name: name.to_string(),
            kind,
            signature: sig.map(|s| s.to_string()),
            summary: summary.map(|s| s.to_string()),
            start_line: 1,
            end_line: 10,
            start_byte: 0,
            end_byte: 100,
        }
    }

    #[test]
    fn test_export_empty_db() {
        let db = MockExportStore::empty();
        let result = export_markdown(&db, None, None).unwrap();
        assert!(result.contains("# Code Structure Index"));
        assert!(result.contains("**Files:** 0"));
    }

    #[test]
    fn test_export_file_with_no_symbols() {
        let mut db = MockExportStore::empty();
        db.files = vec![make_file(1, "src/empty.rs", "rust")];
        db.stats = (1, 0, 0);

        let result = export_markdown(&db, None, None).unwrap();
        assert!(result.contains("`src/empty.rs`"));
        assert!(result.contains("*No symbols extracted.*"));
    }

    #[test]
    fn test_export_symbol_with_signature() {
        let mut db = MockExportStore::empty();
        db.files = vec![make_file(1, "src/lib.rs", "rust")];
        db.symbols.insert(
            1,
            vec![make_sym(
                10,
                1,
                "my_fn",
                SymbolKind::Function,
                Some("fn my_fn(x: i32) -> bool"),
                None,
            )],
        );
        db.stats = (1, 1, 0);

        let result = export_markdown(&db, None, None).unwrap();
        assert!(result.contains("```rust"));
        assert!(result.contains("fn my_fn(x: i32) -> bool"));
    }

    #[test]
    fn test_export_symbol_without_signature() {
        let mut db = MockExportStore::empty();
        db.files = vec![make_file(1, "src/lib.rs", "rust")];
        db.symbols.insert(
            1,
            vec![make_sym(10, 1, "MY_CONST", SymbolKind::Const, None, None)],
        );
        db.stats = (1, 1, 0);

        let result = export_markdown(&db, None, None).unwrap();
        assert!(result.contains("const `MY_CONST`"));
        assert!(!result.contains("```"));
    }

    #[test]
    fn test_export_symbol_with_summary() {
        let mut db = MockExportStore::empty();
        db.files = vec![make_file(1, "src/lib.rs", "rust")];
        db.symbols.insert(
            1,
            vec![make_sym(
                10,
                1,
                "foo",
                SymbolKind::Function,
                None,
                Some("Does something important"),
            )],
        );
        db.stats = (1, 1, 0);

        let result = export_markdown(&db, None, None).unwrap();
        assert!(result.contains("> Does something important"));
    }

    #[test]
    fn test_export_symbol_with_children() {
        let mut db = MockExportStore::empty();
        db.files = vec![make_file(1, "src/lib.rs", "rust")];
        db.symbols.insert(
            1,
            vec![make_sym(10, 1, "MyStruct", SymbolKind::Struct, None, None)],
        );
        db.children.insert(
            10,
            vec![Symbol {
                id: 11,
                file_id: 1,
                parent_id: Some(10),
                name: "new".to_string(),
                kind: SymbolKind::Method,
                signature: Some("fn new() -> Self".to_string()),
                summary: None,
                start_line: 5,
                end_line: 8,
                start_byte: 50,
                end_byte: 80,
            }],
        );
        db.stats = (1, 2, 0);

        let result = export_markdown(&db, None, None).unwrap();
        assert!(result.contains("**Members:**"));
        assert!(result.contains("`fn new() -> Self`"));
    }

    #[test]
    fn test_export_file_with_imports() {
        let mut db = MockExportStore::empty();
        db.files = vec![make_file(1, "src/lib.rs", "rust")];
        db.symbols.insert(
            1,
            vec![make_sym(10, 1, "foo", SymbolKind::Function, None, None)],
        );
        db.deps.insert(
            1,
            vec![Dependency {
                id: 1,
                source_file_id: 1,
                source_symbol_id: None,
                target_file_id: Some(2),
                target_symbol_id: None,
                dep_type: DepType::Imports,
                level: crate::model::DepLevel::File,
                raw_import: Some("std::io".to_string()),
            }],
        );
        db.stats = (1, 1, 1);

        let result = export_markdown(&db, None, None).unwrap();
        assert!(result.contains("**Imports:**"));
        assert!(result.contains("`std::io`"));
    }

    #[test]
    fn test_export_token_budget_truncation() {
        let mut db = MockExportStore::empty();
        // Create many files to exceed a tiny budget
        let mut files = vec![];
        for i in 0..20 {
            let f = make_file(i, &format!("src/file_{}.rs", i), "rust");
            files.push(f);
            db.symbols.insert(
                i,
                vec![make_sym(
                    i * 10,
                    i,
                    &format!("fn_{}", i),
                    SymbolKind::Function,
                    Some(&format!("fn fn_{}() -> i32", i)),
                    None,
                )],
            );
        }
        db.files = files;
        db.stats = (20, 20, 0);

        // Very small budget: 50 tokens = 200 chars
        let result = export_markdown(&db, None, Some(50)).unwrap();
        assert!(result.contains("*Output truncated at"));
    }

    #[test]
    fn test_export_fence_lang_uses_file_language() {
        // Verify that the fence language comes directly from file.language,
        // so adding a new language requires no changes to core.
        for (path, lang, expected_fence) in [
            ("src/lib.rs", "rust", "```rust"),
            ("src/app.ts", "typescript", "```typescript"),
            ("cmd/main.go", "go", "```go"),
            ("src/main.py", "python", "```python"),
        ] {
            let mut db = MockExportStore::empty();
            db.files = vec![make_file(1, path, lang)];
            db.symbols.insert(
                1,
                vec![make_sym(
                    10,
                    1,
                    "f",
                    SymbolKind::Function,
                    Some("fn f()"),
                    None,
                )],
            );
            db.stats = (1, 1, 0);

            let result = export_markdown(&db, None, None).unwrap();
            assert!(
                result.contains(expected_fence),
                "language '{}' should produce fence '{}', got:\n{}",
                lang,
                expected_fence,
                result
            );
        }
    }

    #[test]
    fn test_export_import_without_raw_import() {
        let mut db = MockExportStore::empty();
        db.files = vec![make_file(1, "src/lib.rs", "rust")];
        db.symbols.insert(
            1,
            vec![make_sym(10, 1, "foo", SymbolKind::Function, None, None)],
        );
        db.deps.insert(
            1,
            vec![Dependency {
                id: 1,
                source_file_id: 1,
                source_symbol_id: None,
                target_file_id: Some(2),
                target_symbol_id: None,
                dep_type: DepType::Imports,
                level: crate::model::DepLevel::File,
                raw_import: None,
            }],
        );
        db.stats = (1, 1, 1);

        let result = export_markdown(&db, None, None).unwrap();
        assert!(result.contains("`(unknown)`"));
    }

    #[test]
    fn test_export_non_import_deps_excluded() {
        let mut db = MockExportStore::empty();
        db.files = vec![make_file(1, "src/lib.rs", "rust")];
        db.symbols.insert(
            1,
            vec![make_sym(10, 1, "foo", SymbolKind::Function, None, None)],
        );
        db.deps.insert(
            1,
            vec![Dependency {
                id: 1,
                source_file_id: 1,
                source_symbol_id: None,
                target_file_id: Some(2),
                target_symbol_id: None,
                dep_type: DepType::Calls,
                level: crate::model::DepLevel::Symbol,
                raw_import: None,
            }],
        );
        db.stats = (1, 1, 1);

        let result = export_markdown(&db, None, None).unwrap();
        assert!(!result.contains("**Imports:**"));
    }

    #[test]
    fn test_export_child_without_signature_uses_name() {
        let mut db = MockExportStore::empty();
        db.files = vec![make_file(1, "src/lib.rs", "rust")];
        db.symbols.insert(
            1,
            vec![make_sym(10, 1, "MyStruct", SymbolKind::Struct, None, None)],
        );
        db.children.insert(
            10,
            vec![Symbol {
                id: 11,
                file_id: 1,
                parent_id: Some(10),
                name: "field_x".to_string(),
                kind: SymbolKind::Variable,
                signature: None,
                summary: None,
                start_line: 3,
                end_line: 3,
                start_byte: 20,
                end_byte: 40,
            }],
        );
        db.stats = (1, 2, 0);

        let result = export_markdown(&db, None, None).unwrap();
        assert!(result.contains("`field_x`"));
    }
}