// SPDX-License-Identifier: Apache-2.0
// SPDX-FileCopyrightText: Copyright The LanceDB Authors

use pyo3::prelude::*;
use pyo3::types::PyDict;
use std::collections::HashMap;

/// A wrapper around a Python HeaderProvider that can be called from Rust
pub struct PyHeaderProvider {
    provider: Py<PyAny>,
}

impl Clone for PyHeaderProvider {
    fn clone(&self) -> Self {
        Python::with_gil(|py| Self {
            provider: self.provider.clone_ref(py),
        })
    }
}

impl PyHeaderProvider {
    pub fn new(provider: Py<PyAny>) -> Self {
        Self { provider }
    }

    /// Get headers from the Python provider (internal implementation)
    fn get_headers_internal(&self) -> Result<HashMap<String, String>, String> {
        Python::with_gil(|py| {
            // Call the get_headers method
            let result = self.provider.call_method0(py, "get_headers");

            match result {
                Ok(headers_py) => {
                    // Convert Python dict to Rust HashMap
                    let bound_headers = headers_py.bind(py);
                    let dict: &Bound<PyDict> = bound_headers.downcast().map_err(|e| {
                        format!("HeaderProvider.get_headers must return a dict: {}", e)
                    })?;

                    let mut headers = HashMap::new();
                    for (key, value) in dict {
                        let key_str: String = key
                            .extract()
                            .map_err(|e| format!("Header key must be string: {}", e))?;
                        let value_str: String = value
                            .extract()
                            .map_err(|e| format!("Header value must be string: {}", e))?;
                        headers.insert(key_str, value_str);
                    }
                    Ok(headers)
                }
                Err(e) => Err(format!("Failed to get headers from provider: {}", e)),
            }
        })
    }
}

#[cfg(feature = "remote")]
#[async_trait::async_trait]
impl lancedb::remote::HeaderProvider for PyHeaderProvider {
    async fn get_headers(&self) -> lancedb::error::Result<HashMap<String, String>> {
        self.get_headers_internal()
            .map_err(|e| lancedb::Error::Runtime { message: e })
    }
}

impl std::fmt::Debug for PyHeaderProvider {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(f, "PyHeaderProvider")
    }
}