// status.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::status` module provided by the

//! `hg-core` crate. From Python, this will be seen as

//! `rustext.dirstate.status`.

use crate::{dirstate::DirstateMap, exceptions::FallbackError};

use cpython::{

    exc::ValueError, ObjectProtocol, PyBool, PyBytes, PyErr, PyList, PyObject,

    PyResult, PyTuple, Python, PythonObject, ToPyObject,

};

use hg::dirstate::status::StatusPath;

use hg::matchers::{

    DifferenceMatcher, IntersectionMatcher, Matcher, NeverMatcher,

    PatternMatcher, UnionMatcher,

};

use hg::{

    matchers::{AlwaysMatcher, FileMatcher, IncludeMatcher},

    parse_pattern_syntax,

    utils::{

        files::{get_bytes_from_path, get_path_from_bytes},

        hg_path::{HgPath, HgPathBuf},

    },

    BadMatch, DirstateStatus, IgnorePattern, PatternError, PatternFileWarning,

    StatusError, StatusOptions,

};

use std::borrow::Borrow;

fn collect_status_path_list(py: Python, paths: &[StatusPath<'_>]) -> PyList {

    collect_pybytes_list(py, paths.iter().map(|item| &*item.path))

}

/// This will be useless once trait impls for collection are added to `PyBytes`

/// upstream.

fn collect_pybytes_list(

    py: Python,

    iter: impl Iterator<Item = impl AsRef<HgPath>>,

) -> PyList {

    let list = PyList::new(py, &[]);

    for path in iter {

        list.append(

            py,

            PyBytes::new(py, path.as_ref().as_bytes()).into_object(),

        )

    }

    list

}

fn collect_bad_matches(

    py: Python,

    collection: &[(impl AsRef<HgPath>, BadMatch)],

) -> PyResult<PyList> {

    let list = PyList::new(py, &[]);

    let os = py.import("os")?;

    let get_error_message = |code: i32| -> PyResult<_> {

        os.call(

            py,

            "strerror",

            PyTuple::new(py, &[code.to_py_object(py).into_object()]),

            None,

        )

    };

    for (path, bad_match) in collection.iter() {

        let message = match bad_match {

            BadMatch::OsError(code) => get_error_message(*code)?,

            BadMatch::BadType(bad_type) => {

                format!("unsupported file type (type is {})", bad_type)

                    .to_py_object(py)

                    .into_object()

            }

        };

        list.append(

            py,

            (PyBytes::new(py, path.as_ref().as_bytes()), message)

                .to_py_object(py)

                .into_object(),

        )

    }

    Ok(list)

}

fn handle_fallback(py: Python, err: StatusError) -> PyErr {

    match err {

        StatusError::Pattern(e) => {

            let as_string = e.to_string();

            log::trace!("Rust status fallback: `{}`", &as_string);

            PyErr::new::<FallbackError, _>(py, &as_string)

        }

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

    }

}

pub fn status_wrapper(

    py: Python,

    dmap: DirstateMap,

    matcher: PyObject,

    root_dir: PyObject,

    ignore_files: PyList,

    check_exec: bool,

    list_clean: bool,

    list_ignored: bool,

    list_unknown: bool,

    collect_traversed_dirs: bool,

) -> PyResult<PyTuple> {

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

    let root_dir = get_path_from_bytes(bytes.data(py));

    let dmap: DirstateMap = dmap.to_py_object(py);

    let mut dmap = dmap.get_inner_mut(py);

    let ignore_files: PyResult<Vec<_>> = ignore_files

        .iter(py)

        .map(|b| {

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

            Ok(get_path_from_bytes(file.data(py)).to_owned())

        })

        .collect();

    let ignore_files = ignore_files?;

    // The caller may call `copymap.items()` separately

    let list_copies = false;

    let after_status = |res: Result<(DirstateStatus<'_>, _), StatusError>| {

        let (status_res, warnings) =

            res.map_err(|e| handle_fallback(py, e))?;

        build_response(py, status_res, warnings)

    };

    let matcher = extract_matcher(py, matcher)?;

    dmap.with_status(

        &*matcher,

        root_dir.to_path_buf(),

        ignore_files,

        StatusOptions {

            check_exec,

            list_clean,

            list_ignored,

            list_unknown,

            list_copies,

            collect_traversed_dirs,

        },

        after_status,

    )

}

/// Transform a Python matcher into a Rust matcher.

fn extract_matcher(

    py: Python,

    matcher: PyObject,

) -> PyResult<Box<dyn Matcher + Sync>> {

    let tampered = matcher

        .call_method(py, "was_tampered_with", PyTuple::empty(py), None)?

        .extract::<PyBool>(py)?

        .is_true();

    if tampered {

        return Err(handle_fallback(

            py,

            StatusError::Pattern(PatternError::UnsupportedSyntax(

                "Pattern matcher was tampered with!".to_string(),

            )),

        ));

    };

    match matcher.get_type(py).name(py).borrow() {

        "alwaysmatcher" => Ok(Box::new(AlwaysMatcher)),

        "nevermatcher" => Ok(Box::new(NeverMatcher)),

        "exactmatcher" => {

            let files = matcher.call_method(

                py,

                "files",

                PyTuple::new(py, &[]),

                None,

            )?;

            let files: PyList = files.cast_into(py)?;

            let files: PyResult<Vec<HgPathBuf>> = files

                .iter(py)

                .map(|f| {

                    Ok(HgPathBuf::from_bytes(

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

                    ))

                })

                .collect();

            let files = files?;

            let file_matcher = FileMatcher::new(files)

                .map_err(|e| PyErr::new::<ValueError, _>(py, e.to_string()))?;

            Ok(Box::new(file_matcher))

        }

        "includematcher" => {

            // Get the patterns from Python even though most of them are

            // redundant with those we will parse later on, as they include

            // those passed from the command line.

            let matcher = IncludeMatcher::new(ignore_patterns)

                .map_err(|e| handle_fallback(py, e.into()))?;

            Ok(Box::new(matcher))

        }

        "unionmatcher" => {

            let matchers: PyResult<Vec<_>> = matcher

                .getattr(py, "_matchers")?

                .iter(py)?

                .map(|py_matcher| extract_matcher(py, py_matcher?))

                .collect();

            Ok(Box::new(UnionMatcher::new(matchers?)))

        }

        "intersectionmatcher" => {

            let m1 = extract_matcher(py, matcher.getattr(py, "_m1")?)?;

            let m2 = extract_matcher(py, matcher.getattr(py, "_m2")?)?;

            Ok(Box::new(IntersectionMatcher::new(m1, m2)))

        }

        "differencematcher" => {

            let m1 = extract_matcher(py, matcher.getattr(py, "_m1")?)?;

            let m2 = extract_matcher(py, matcher.getattr(py, "_m2")?)?;

            Ok(Box::new(DifferenceMatcher::new(m1, m2)))

        }

        "patternmatcher" => {

                .map_err(|e| handle_fallback(py, e.into()))?;

            Ok(Box::new(matcher))

        }

        e => Err(PyErr::new::<FallbackError, _>(

            py,

            format!("Unsupported matcher {}", e),

        )),

    }

}

fn build_response(

    py: Python,

    status_res: DirstateStatus,

    warnings: Vec<PatternFileWarning>,

) -> PyResult<PyTuple> {

    let modified = collect_status_path_list(py, &status_res.modified);

    let added = collect_status_path_list(py, &status_res.added);

    let removed = collect_status_path_list(py, &status_res.removed);

    let deleted = collect_status_path_list(py, &status_res.deleted);

    let clean = collect_status_path_list(py, &status_res.clean);

    let ignored = collect_status_path_list(py, &status_res.ignored);

    let unknown = collect_status_path_list(py, &status_res.unknown);

    let unsure = collect_status_path_list(py, &status_res.unsure);

    let bad = collect_bad_matches(py, &status_res.bad)?;

    let traversed = collect_pybytes_list(py, status_res.traversed.iter());

    let dirty = status_res.dirty.to_py_object(py);

    let py_warnings = PyList::new(py, &[]);

    for warning in warnings.iter() {

        // We use duck-typing on the Python side for dispatch, good enough for

        // now.

        match warning {

            PatternFileWarning::InvalidSyntax(file, syn) => {

                py_warnings.append(

                    py,

                    (

                        PyBytes::new(py, &get_bytes_from_path(file)),

                        PyBytes::new(py, syn),

                    )

                        .to_py_object(py)

                        .into_object(),

                );

            }

            PatternFileWarning::NoSuchFile(file) => py_warnings.append(

                py,

                PyBytes::new(py, &get_bytes_from_path(file)).into_object(),

            ),

        }

    }

    Ok(PyTuple::new(

        py,

        &[

            unsure.into_object(),

            modified.into_object(),

            added.into_object(),

            removed.into_object(),

            deleted.into_object(),

            clean.into_object(),

            ignored.into_object(),

            unknown.into_object(),

            py_warnings.into_object(),

            bad.into_object(),

            traversed.into_object(),

            dirty.into_object(),

        ][..],

    ))

}