py2pyd 0.1.1

use anyhow::{Context, Result};
use log::{debug, info};
use rustpython_parser::ast;
use std::path::{Path, PathBuf};

/// Represents a transformed Python module
pub struct TransformedModule {
    pub module_name: String,
    pub rust_code: String,
    pub build_script: String,
    pub cargo_toml: String,
    pub build_dir: PathBuf,
}

/// Transform a Python AST into Rust code using `PyO3`
pub fn transform_ast(ast: &ast::Suite, module_name: &str, optimize_level: u8) -> String {
    info!("Transforming Python AST to Rust code");
    debug!(
        "Module name: {}, Optimization level: {}",
        module_name, optimize_level
    );

    // This is a simplified implementation
    // In a real implementation, we would analyze the AST and generate
    // appropriate Rust code with PyO3 bindings

    let mut rust_code = String::new();

    // Add standard imports
    rust_code.push_str("use pyo3::prelude::*;\n");
    rust_code.push_str("use pyo3::wrap_pyfunction;\n\n");

    // Generate module
    rust_code.push_str(&format!(
        "#[pymodule]\nfn {}(_py: Python, m: &PyModule) -> PyResult<()> {{\n",
        module_name
    ));

    // Transform functions
    for func in crate::parser::extract_functions(ast) {
        if let ast::Stmt::FunctionDef(func_def) = func {
            rust_code.push_str(&format!(
                "    m.add_function(wrap_pyfunction!({}, m)?)?;\n",
                func_def.name
            ));
        }
    }

    // Transform classes
    for class in crate::parser::extract_classes(ast) {
        if let ast::Stmt::ClassDef(class_def) = class {
            rust_code.push_str(&format!("    m.add_class::<{}>()?;\n", class_def.name));
        }
    }

    rust_code.push_str("    Ok(())\n");
    rust_code.push_str("}\n\n");

    // Generate function implementations
    for func in crate::parser::extract_functions(ast) {
        if let ast::Stmt::FunctionDef(func_def) = func {
            rust_code.push_str(&format!(
                "#[pyfunction]\nfn {}(py: Python) -> PyResult<PyObject> {{\n",
                func_def.name
            ));
            rust_code.push_str("    // Auto-generated function implementation\n");
            rust_code.push_str("    Ok(py.None())\n");
            rust_code.push_str("}\n\n");
        }
    }

    // Generate class implementations
    for class in crate::parser::extract_classes(ast) {
        if let ast::Stmt::ClassDef(class_def) = class {
            rust_code.push_str(&format!("#[pyclass]\nstruct {} {{\n", class_def.name));
            rust_code.push_str("    // Auto-generated class implementation\n");
            rust_code.push_str("}\n\n");

            rust_code.push_str(&format!("#[pymethods]\nimpl {} {{\n", class_def.name));
            rust_code.push_str("    #[new]\n");
            rust_code.push_str("    fn new() -> Self {\n");
            rust_code.push_str(&format!("        {}{{ }}\n", class_def.name));
            rust_code.push_str("    }\n");
            rust_code.push_str("}\n\n");
        }
    }

    debug!("Generated {} lines of Rust code", rust_code.lines().count());
    rust_code
}

/// Generate a Cargo.toml file for the transformed module
pub fn generate_cargo_toml(module_name: &str, optimize_level: u8) -> String {
    let mut cargo_toml = String::new();

    cargo_toml.push_str(&format!("[package]\n"));
    cargo_toml.push_str(&format!("name = \"{}\"\n", module_name));
    cargo_toml.push_str(&format!("version = \"0.1.0\"\n"));
    cargo_toml.push_str(&format!("edition = \"2021\"\n\n"));

    cargo_toml.push_str(&format!("[lib]\n"));
    cargo_toml.push_str(&format!("name = \"{}\"\n", module_name));
    cargo_toml.push_str(&format!("crate-type = [\"cdylib\"]\n\n"));

    // Add maturin configuration
    cargo_toml.push_str(&format!("[package.metadata.maturin]\n"));
    cargo_toml.push_str(&format!("name = \"{}\"\n", module_name));
    cargo_toml.push_str(&format!("binding = \"pyo3\"\n"));
    cargo_toml.push_str(&format!("strip = true\n\n"));

    cargo_toml.push_str(&format!("[dependencies]\n"));
    cargo_toml.push_str(&format!(
        "pyo3 = {{ version = \"0.19\", features = [\"extension-module\"] }}\n"
    ));

    // Add optimization flags
    cargo_toml.push_str(&format!("\n[profile.release]\n"));
    match optimize_level {
        0 => {
            cargo_toml.push_str(&format!("opt-level = 0\n"));
        }
        1 => {
            cargo_toml.push_str(&format!("opt-level = 1\n"));
        }
        2 => {
            cargo_toml.push_str(&format!("opt-level = 2\n"));
        }
        _ => {
            cargo_toml.push_str(&format!("opt-level = 3\n"));
            cargo_toml.push_str(&format!("lto = true\n"));
            cargo_toml.push_str(&format!("codegen-units = 1\n"));
        }
    }

    cargo_toml
}

/// Transform a Python file into a Rust project
pub fn transform_file(input_path: &Path, optimize_level: u8) -> Result<TransformedModule> {
    info!("Transforming Python file: {}", input_path.display());

    // Parse the Python file
    let ast = crate::parser::parse_file(input_path)
        .with_context(|| format!("Failed to parse Python file: {}", input_path.display()))?;

    // Get the module name from the file name
    let module_name = input_path
        .file_stem()
        .and_then(|s| s.to_str())
        .ok_or_else(|| anyhow::anyhow!("Invalid file name"))?;

    // Transform the AST to Rust code
    let rust_code = transform_ast(&ast, module_name, optimize_level);

    // Generate Cargo.toml
    let cargo_toml = generate_cargo_toml(module_name, optimize_level);

    // Create a temporary directory for the build
    let temp_dir = tempfile::tempdir().with_context(|| "Failed to create temporary directory")?;
    let build_dir = temp_dir.path().to_path_buf();
    // We'll let the temp_dir be dropped, which will clean up the directory
    // In a real implementation, we might want to keep it for debugging

    // Create the build script
    let build_script = "cargo build --release".to_string();

    Ok(TransformedModule {
        module_name: module_name.to_string(),
        rust_code,
        build_script,
        cargo_toml,
        build_dir,
    })
}