// PyO3 FFI bindings for Python-Rust interop

use pyo3::prelude::*;
use pyo3::types::PyBytes;
use serde::{Deserialize, Serialize};

/// Rust analyzer exposed to Python
#[pyclass(name = "RustAnalyzer")]
pub struct RustAnalyzer {
    /// Internal analyzer state
    #[pyo3(get, set)]
    pub project_path: String,

    /// Whether to use GPU acceleration
    #[pyo3(get, set)]
    pub use_gpu: bool,

    /// Internal state placeholder
    initialized: bool,
}

#[pymethods]
impl RustAnalyzer {
    /// Create a new Rust analyzer
    #[new]
    #[pyo3(signature = (project_path, use_gpu=false))]
    pub fn new(project_path: String, use_gpu: bool) -> Self {
        Self {
            project_path,
            use_gpu,
            initialized: false,
        }
    }

    /// Initialize the analyzer
    pub fn initialize(&mut self) -> PyResult<()> {
        // Placeholder - will initialize actual components during sub-track
        self.initialized = true;
        Ok(())
    }

    /// Parse a file and return AST
    pub fn parse_file(&self, file_path: &str) -> PyResult<String> {
        if !self.initialized {
            return Err(PyErr::new::<pyo3::exceptions::PyRuntimeError, _>(
                "Analyzer not initialized",
            ));
        }

        // Placeholder - will use leparse during sub-track
        Ok(serde_json::to_string(&serde_json::json!({
            "file_path": file_path,
            "nodes": []
        })).unwrap_or_default())
    }

    /// Build weighted context from entry nodes
    pub fn build_context(
        &self,
        entry_nodes: Vec<String>,
        token_budget: usize,
    ) -> PyResult<String> {
        if !self.initialized {
            return Err(PyErr::new::<pyo3::exceptions::PyRuntimeError, _>(
                "Analyzer not initialized",
            ));
        }

        // Placeholder - will use legraphe gravity traversal during sub-track
        Ok(format!(
            r#"{{"entry_nodes": {:?}, "token_budget": {}, "context": []}}"#,
            entry_nodes, token_budget
        ))
    }

    /// Get node by symbol name
    pub fn get_node(&self, symbol: &str) -> PyResult<String> {
        if !self.initialized {
            return Err(PyErr::new::<pyo3::exceptions::PyRuntimeError, _>(
                "Analyzer not initialized",
            ));
        }

        // Placeholder - will query storage during sub-track
        Ok(format!(r#"{{"symbol": "{}", "found": false}}"#, symbol))
    }

    /// __repr__ for debugging
    pub fn __repr__(&self) -> String {
        format!("RustAnalyzer(project_path={}, use_gpu={})", self.project_path, self.use_gpu)
    }

    /// __str__ for display
    pub fn __str__(&self) -> String {
        self.__repr__()
    }
}

/// Build weighted context from entry nodes (function version)
#[pyfunction(signature = (entry_nodes, token_budget=2000))]
pub fn build_weighted_context(entry_nodes: Vec<String>, token_budget: usize) -> PyResult<String> {
    // Placeholder - will use legraphe during sub-track
    Ok(format!(
        r#"{{"entry_nodes": {:?}, "token_budget": {}, "context": []}}"#,
        entry_nodes, token_budget
    ))
}

/// Context expansion result
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ContextExpansion {
    /// Entry nodes
    pub entry_nodes: Vec<String>,

    /// Expanded context nodes
    pub context_nodes: Vec<String>,

    /// Total tokens used
    pub tokens_used: usize,

    /// Context as string
    pub context_string: String,
}

/// Parse result
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ParseResult {
    /// File path
    pub file_path: String,

    /// Parsed nodes
    pub nodes: Vec<AstNode>,

    /// Parse errors if any
    pub errors: Vec<String>,
}

/// AST node
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct AstNode {
    /// Node type
    pub node_type: String,

    /// Name
    pub name: String,

    /// Byte range
    pub byte_range: (usize, usize),

    /// Line number
    pub line_number: usize,
}

/// Python module error type
#[derive(Debug, thiserror::Error)]
pub enum BridgeError {
    #[error("Initialization failed: {0}")]
    InitFailed(String),

    #[error("Parse error: {0}")]
    ParseError(String),

    #[error("IO error: {0}")]
    Io(#[from] std::io::Error),

    #[error("Serialization error: {0}")]
    Serialization(#[from] serde_json::Error),
}

impl From<BridgeError> for PyErr {
    fn from(err: BridgeError) -> Self {
        PyErr::new::<pyo3::exceptions::PyRuntimeError, _>(err.to_string())
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_analyzer_creation() {
        let analyzer = RustAnalyzer::new("/test/path".to_string(), true);
        assert_eq!(analyzer.project_path, "/test/path");
        assert!(analyzer.use_gpu);
    }

    #[test]
    fn test_analyzer_initialization() {
        let mut analyzer = RustAnalyzer::new("/test/path".to_string(), false);
        assert!(analyzer.initialize().is_ok());
        assert!(analyzer.initialized);
    }
}
