// dirstate_map.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::dirstate_map` file provided by the

//! `hg-core` package.

use std::cell::{RefCell, RefMut};

use std::convert::TryInto;

use cpython::{

    exc, PyBool, PyBytes, PyClone, PyDict, PyErr, PyList, PyNone, PyObject,

    PyResult, Python, PythonObject, ToPyObject, UnsafePyLeaked,

};

use crate::{

    dirstate::copymap::{CopyMap, CopyMapItemsIterator, CopyMapKeysIterator},

    dirstate::item::DirstateItem,

    pybytes_deref::PyBytesDeref,

};

use hg::{

    dirstate::parsers::Timestamp,

    dirstate_tree::dirstate_map::DirstateMap as TreeDirstateMap,

    dirstate_tree::dispatch::DirstateMapMethods,

    dirstate_tree::on_disk::DirstateV2ParseError,

    dirstate_tree::owning::OwningDirstateMap,

    revlog::Node,

    utils::files::normalize_case,

    utils::hg_path::{HgPath, HgPathBuf},

};

// TODO

//     This object needs to share references to multiple members of its Rust

//     inner struct, namely `copy_map`, `dirs` and `all_dirs`.

//     Right now `CopyMap` is done, but it needs to have an explicit reference

//     to `RustDirstateMap` which itself needs to have an encapsulation for

//     every method in `CopyMap` (copymapcopy, etc.).

//     This is ugly and hard to maintain.

//     The same logic applies to `dirs` and `all_dirs`, however the `Dirs`

//     `py_class!` is already implemented and does not mention

//     `RustDirstateMap`, rightfully so.

//     All attributes also have to have a separate refcount data attribute for

//     leaks, with all methods that go along for reference sharing.

py_class!(pub class DirstateMap |py| {

    @shared data inner: Box<dyn DirstateMapMethods + Send>;

    /// Returns a `(dirstate_map, parents)` tuple

    @staticmethod

    def new_v1(

        on_disk: PyBytes,

    ) -> PyResult<PyObject> {

        let parents = parents.map(|p| {

            let p1 = PyBytes::new(py, p.p1.as_bytes());

            let p2 = PyBytes::new(py, p.p2.as_bytes());

            (p1, p2)

        });

        Ok((map, parents).to_py_object(py).into_object())

    }

    /// Returns a DirstateMap

    @staticmethod

    def new_v2(

        on_disk: PyBytes,

        data_size: usize,

        tree_metadata: PyBytes,

    ) -> PyResult<PyObject> {

        let dirstate_error = |e: DirstateError| {

            PyErr::new::<exc::OSError, _>(py, format!("Dirstate error: {:?}", e))

        };

        let on_disk = PyBytesDeref::new(py, on_disk);

        let mut map = OwningDirstateMap::new_empty(on_disk);

        let (on_disk, map_placeholder) = map.get_mut_pair();

        *map_placeholder = TreeDirstateMap::new_v2(

            on_disk, data_size, tree_metadata.data(py),

        ).map_err(dirstate_error)?;

        let map = Self::create_instance(py, Box::new(map))?;

        Ok(map.into_object())

    }

    def clear(&self) -> PyResult<PyObject> {

        self.inner(py).borrow_mut().clear();

        Ok(py.None())

    }

    def get(

        &self,

        key: PyObject,

        default: Option<PyObject> = None

    ) -> PyResult<Option<PyObject>> {

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

        match self

            .inner(py)

            .borrow()

            .get(HgPath::new(key.data(py)))

            .map_err(|e| v2_error(py, e))?

        {

            Some(entry) => {

                Ok(Some(DirstateItem::new_as_pyobject(py, entry)?))

            },

            None => Ok(default)

        }

    }

    def set_dirstate_item(

        &self,

        path: PyObject,

        item: DirstateItem

    ) -> PyResult<PyObject> {

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

        let filename = HgPath::new(f.data(py));

        self.inner(py)

            .borrow_mut()

            .set_entry(filename, item.get_entry(py))

            .map_err(|e| v2_error(py, e))?;

        Ok(py.None())

    }

    def addfile(

        &self,

        f: PyBytes,

        item: DirstateItem,

    ) -> PyResult<PyNone> {

        let filename = HgPath::new(f.data(py));

        let entry = item.get_entry(py);

        self.inner(py)

            .borrow_mut()

            .add_file(filename, entry)

            .map_err(|e |dirstate_error(py, e))?;

        Ok(PyNone)

    }

    def removefile(

        &self,

        f: PyObject,

        in_merge: PyObject

    ) -> PyResult<PyObject> {

        self.inner(py).borrow_mut()

            .remove_file(

                HgPath::new(f.extract::<PyBytes>(py)?.data(py)),

                in_merge.extract::<PyBool>(py)?.is_true(),

            )

            .or_else(|_| {

                Err(PyErr::new::<exc::OSError, _>(

                    py,

                    "Dirstate error".to_string(),

                ))

            })?;

        Ok(py.None())

    }

    def drop_item_and_copy_source(

        &self,

        f: PyBytes,

    ) -> PyResult<PyNone> {

        self.inner(py)

            .borrow_mut()

            .drop_entry_and_copy_source(HgPath::new(f.data(py)))

            .map_err(|e |dirstate_error(py, e))?;

        Ok(PyNone)

    }

    def hastrackeddir(&self, d: PyObject) -> PyResult<PyBool> {

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

        Ok(self.inner(py).borrow_mut()

            .has_tracked_dir(HgPath::new(d.data(py)))

            .map_err(|e| {

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

            })?

            .to_py_object(py))

    }

    def hasdir(&self, d: PyObject) -> PyResult<PyBool> {

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

        Ok(self.inner(py).borrow_mut()

            .has_dir(HgPath::new(d.data(py)))

            .map_err(|e| {

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

            })?

            .to_py_object(py))

    }

    def write_v1(

        &self,

        p1: PyObject,

        p2: PyObject,

        now: PyObject

    ) -> PyResult<PyBytes> {

        let now = Timestamp(now.extract(py)?);

        let mut inner = self.inner(py).borrow_mut();

        let parents = DirstateParents {

            p1: extract_node_id(py, &p1)?,

            p2: extract_node_id(py, &p2)?,

        };

        let result = inner.pack_v1(parents, now);

        match result {

            Ok(packed) => Ok(PyBytes::new(py, &packed)),

            Err(_) => Err(PyErr::new::<exc::OSError, _>(

                py,

                "Dirstate error".to_string(),

            )),

        }

    }

    /// Returns new data together with whether that data should be appended to

    /// the existing data file whose content is at `self.on_disk` (True),

    /// instead of written to a new data file (False).

    def write_v2(

        &self,

        now: PyObject,

        can_append: bool,

    ) -> PyResult<PyObject> {

        let now = Timestamp(now.extract(py)?);

        let mut inner = self.inner(py).borrow_mut();

        let result = inner.pack_v2(now, can_append);

        match result {

            Ok((packed, tree_metadata, append)) => {

                let packed = PyBytes::new(py, &packed);

                let tree_metadata = PyBytes::new(py, &tree_metadata);

                let tuple = (packed, tree_metadata, append);

                Ok(tuple.to_py_object(py).into_object())

            },

            Err(_) => Err(PyErr::new::<exc::OSError, _>(

                py,

                "Dirstate error".to_string(),

            )),

        }

    }

    def filefoldmapasdict(&self) -> PyResult<PyDict> {

        let dict = PyDict::new(py);

        for item in self.inner(py).borrow_mut().iter() {

            let (path, entry) = item.map_err(|e| v2_error(py, e))?;

            if entry.state() != EntryState::Removed {

                let key = normalize_case(path);

                let value = path;

                dict.set_item(

                    py,

                    PyBytes::new(py, key.as_bytes()).into_object(),

                    PyBytes::new(py, value.as_bytes()).into_object(),

                )?;

            }

        }

        Ok(dict)

    }

    def __len__(&self) -> PyResult<usize> {

        Ok(self.inner(py).borrow().len())

    }

    def __contains__(&self, key: PyObject) -> PyResult<bool> {

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

        self.inner(py)

            .borrow()

            .contains_key(HgPath::new(key.data(py)))

            .map_err(|e| v2_error(py, e))

    }

    def __getitem__(&self, key: PyObject) -> PyResult<PyObject> {

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

        let key = HgPath::new(key.data(py));

        match self

            .inner(py)

            .borrow()

            .get(key)

            .map_err(|e| v2_error(py, e))?

        {

            Some(entry) => {

                Ok(DirstateItem::new_as_pyobject(py, entry)?)

            },

            None => Err(PyErr::new::<exc::KeyError, _>(

                py,

                String::from_utf8_lossy(key.as_bytes()),

            )),

        }

    }

    def keys(&self) -> PyResult<DirstateMapKeysIterator> {

        let leaked_ref = self.inner(py).leak_immutable();

        DirstateMapKeysIterator::from_inner(

            py,

            unsafe { leaked_ref.map(py, |o| o.iter()) },

        )

    }

    def items(&self) -> PyResult<DirstateMapItemsIterator> {

        let leaked_ref = self.inner(py).leak_immutable();

        DirstateMapItemsIterator::from_inner(

            py,

            unsafe { leaked_ref.map(py, |o| o.iter()) },

        )

    }

    def __iter__(&self) -> PyResult<DirstateMapKeysIterator> {

        let leaked_ref = self.inner(py).leak_immutable();

        DirstateMapKeysIterator::from_inner(

            py,

            unsafe { leaked_ref.map(py, |o| o.iter()) },

        )

    }

    // TODO all copymap* methods, see docstring above

    def copymapcopy(&self) -> PyResult<PyDict> {

        let dict = PyDict::new(py);

        for item in self.inner(py).borrow().copy_map_iter() {

            let (key, value) = item.map_err(|e| v2_error(py, e))?;

            dict.set_item(

                py,

                PyBytes::new(py, key.as_bytes()),

                PyBytes::new(py, value.as_bytes()),

            )?;

        }

        Ok(dict)