// dirstate.rs

//

// Copyright 2019 Raphaël Gomès <rgomes@octobus.net>

//

// This software may be used and distributed according to the terms of the

// GNU General Public License version 2 or any later version.

//! Bindings for the `hg::dirstate` module provided by the

//! `hg-core` package.

//!

//! From Python, this will be seen as `mercurial.rustext.dirstate`

mod copymap;

mod dirs_multiset;

mod dirstate_map;

use crate::dirstate::{dirs_multiset::Dirs, dirstate_map::DirstateMap};

use cpython::{

    exc, PyBytes, PyDict, PyErr, PyModule, PyObject, PyResult, PySequence,

    Python,

};

use hg::{

    utils::hg_path::HgPathBuf, DirstateEntry, DirstateParseError, EntryState,

    StateMap,

};

use libc::{c_char, c_int};

use std::convert::TryFrom;

// C code uses a custom `dirstate_tuple` type, checks in multiple instances

// for this type, and raises a Python `Exception` if the check does not pass.

// Because this type differs only in name from the regular Python tuple, it

// would be a good idea in the near future to remove it entirely to allow

// for a pure Python tuple of the same effective structure to be used,

// rendering this type and the capsule below useless.

pub fn make_dirstate_tuple(

    py: Python,

    entry: &DirstateEntry,

) -> PyResult<PyObject> {

    let &DirstateEntry {

        state,

        mode,

        size,

        mtime,

    } = entry;

    // Explicitly go through u8 first, then cast to platform-specific `c_char`

    // because Into<u8> has a specific implementation while `as c_char` would

    // just do a naive enum cast.

    let state_code: u8 = state.into();

    let maybe_obj = unsafe {

        let ptr = make(state_code as c_char, mode, size, mtime);

        PyObject::from_owned_ptr_opt(py, ptr)

    };

    maybe_obj.ok_or_else(|| PyErr::fetch(py))

}

pub fn extract_dirstate(py: Python, dmap: &PyDict) -> Result<StateMap, PyErr> {

    dmap.items(py)

        .iter()

        .map(|(filename, stats)| {

            let stats = stats.extract::<PySequence>(py)?;

            let state = stats.get_item(py, 0)?.extract::<PyBytes>(py)?;

            let state = EntryState::try_from(state.data(py)[0]).map_err(

                |e: DirstateParseError| {

                    PyErr::new::<exc::ValueError, _>(py, e.to_string())

                },

            )?;

            let mode = stats.get_item(py, 1)?.extract(py)?;

            let size = stats.get_item(py, 2)?.extract(py)?;

            let mtime = stats.get_item(py, 3)?.extract(py)?;

            let filename = filename.extract::<PyBytes>(py)?;

            let filename = filename.data(py);

            Ok((

                HgPathBuf::from(filename.to_owned()),

                DirstateEntry {

                    state,

                    mode,

                    size,

                    mtime,

                },

            ))

        })

        .collect()

}

/// Create the module, with `__package__` given from parent

pub fn init_module(py: Python, package: &str) -> PyResult<PyModule> {

    let dotted_name = &format!("{}.dirstate", package);

    let m = PyModule::new(py, dotted_name)?;

    m.add(py, "__package__", package)?;

    m.add(py, "__doc__", "Dirstate - Rust implementation")?;

    m.add_class::<Dirs>(py)?;

    m.add_class::<DirstateMap>(py)?;

    let sys = PyModule::import(py, "sys")?;

    let sys_modules: PyDict = sys.get(py, "modules")?.extract(py)?;

    sys_modules.set_item(py, dotted_name, &m)?;

    Ok(m)

}