// 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.

use crate::{

    dirstate::{parsers::PARENT_SIZE, EntryState},

};

use core::borrow::Borrow;

use std::collections::{HashMap, HashSet};

use std::convert::TryInto;

use std::iter::FromIterator;

use std::ops::Deref;

use std::time::Duration;

pub type FileFoldMap = HashMap<Vec<u8>, Vec<u8>>;

const NULL_ID: [u8; 20] = [0; 20];

const MTIME_UNSET: i32 = -1;

const SIZE_DIRTY: i32 = -2;

#[derive(Default)]

pub struct DirstateMap {

    state_map: StateMap,

    pub copy_map: CopyMap,

    file_fold_map: Option<FileFoldMap>,

    pub dirs: Option<DirsMultiset>,

    pub all_dirs: Option<DirsMultiset>,

    non_normal_set: HashSet<Vec<u8>>,

    other_parent_set: HashSet<Vec<u8>>,

    parents: Option<DirstateParents>,

    dirty_parents: bool,

}

/// Should only really be used in python interface code, for clarity

impl Deref for DirstateMap {

    type Target = StateMap;

    fn deref(&self) -> &Self::Target {

        &self.state_map

    }

}

impl FromIterator<(Vec<u8>, DirstateEntry)> for DirstateMap {

    fn from_iter<I: IntoIterator<Item = (Vec<u8>, DirstateEntry)>>(

        iter: I,

    ) -> Self {

        Self {

            state_map: iter.into_iter().collect(),

            ..Self::default()

        }

    }

}

impl DirstateMap {

    pub fn new() -> Self {

        Self::default()

    }

    pub fn clear(&mut self) {

        self.state_map.clear();

        self.copy_map.clear();

        self.file_fold_map = None;

        self.non_normal_set.clear();

        self.other_parent_set.clear();

        self.set_parents(&DirstateParents {

            p1: NULL_ID,

            p2: NULL_ID,

        })

    }

    /// Add a tracked file to the dirstate

    pub fn add_file(

        &mut self,

        filename: &[u8],

        old_state: EntryState,

        entry: DirstateEntry,

    ) {

        if old_state == EntryState::Unknown || old_state == EntryState::Removed

        {

            if let Some(ref mut dirs) = self.dirs {

                dirs.add_path(filename)

            }

        }

        if old_state == EntryState::Unknown {

            if let Some(ref mut all_dirs) = self.all_dirs {

                all_dirs.add_path(filename)

            }

        }

        self.state_map.insert(filename.to_owned(), entry.to_owned());

        if entry.state != EntryState::Normal || entry.mtime == MTIME_UNSET {

            self.non_normal_set.insert(filename.to_owned());

        }

        if entry.size == SIZE_DIRTY {

            self.other_parent_set.insert(filename.to_owned());

        }

    }

    /// Mark a file as removed in the dirstate.

    ///

    /// The `size` parameter is used to store sentinel values that indicate

    /// the file's previous state.  In the future, we should refactor this

    /// to be more explicit about what that state is.

    pub fn remove_file(

        &mut self,

        filename: &[u8],

        old_state: EntryState,

        size: i32,

    ) -> Result<(), DirstateMapError> {

        if old_state != EntryState::Unknown && old_state != EntryState::Removed

        {

            if let Some(ref mut dirs) = self.dirs {

                dirs.delete_path(filename)?;

            }

        }

        if old_state == EntryState::Unknown {

            if let Some(ref mut all_dirs) = self.all_dirs {

                all_dirs.add_path(filename);

            }

        }

        if let Some(ref mut file_fold_map) = self.file_fold_map {

            file_fold_map.remove(&filename.to_ascii_uppercase());

        }

        self.state_map.insert(

            filename.to_owned(),

            DirstateEntry {

                state: EntryState::Removed,

                mode: 0,

                size,

                mtime: 0,

            },

        );

        self.non_normal_set.insert(filename.to_owned());

        Ok(())

    }

    /// Remove a file from the dirstate.

    /// Returns `true` if the file was previously recorded.

    pub fn drop_file(

        &mut self,

        filename: &[u8],

        old_state: EntryState,

    ) -> Result<bool, DirstateMapError> {

        let exists = self.state_map.remove(filename).is_some();

        if exists {

            if old_state != EntryState::Removed {

                if let Some(ref mut dirs) = self.dirs {

                    dirs.delete_path(filename)?;

                }

            }

            if let Some(ref mut all_dirs) = self.all_dirs {

                all_dirs.delete_path(filename)?;

            }

        }

        if let Some(ref mut file_fold_map) = self.file_fold_map {

            file_fold_map.remove(&filename.to_ascii_uppercase());

        }

        self.non_normal_set.remove(filename);

        Ok(exists)

    }

    pub fn clear_ambiguous_times(

        &mut self,

        filenames: Vec<Vec<u8>>,

        now: i32,

    ) {

        for filename in filenames {

            let mut changed = false;

            self.state_map

                .entry(filename.to_owned())

                .and_modify(|entry| {

                    if entry.state == EntryState::Normal && entry.mtime == now

                    {

                        changed = true;

                        *entry = DirstateEntry {

                            mtime: MTIME_UNSET,

                            ..*entry

                        };

                    }

                });

            if changed {

                self.non_normal_set.insert(filename.to_owned());

            }

        }

    }

    pub fn non_normal_other_parent_entries(

        &self,

    ) -> (HashSet<Vec<u8>>, HashSet<Vec<u8>>) {

        let mut non_normal = HashSet::new();

        let mut other_parent = HashSet::new();

        for (

            filename,

            DirstateEntry {

                state, size, mtime, ..

            },

        ) in self.state_map.iter()

        {

            if *state != EntryState::Normal || *mtime == MTIME_UNSET {

                non_normal.insert(filename.to_owned());

            }

            if *state == EntryState::Normal && *size == SIZE_DIRTY {

                other_parent.insert(filename.to_owned());

            }

        }

        (non_normal, other_parent)

    }

    /// Both of these setters and their uses appear to be the simplest way to

    /// emulate a Python lazy property, but it is ugly and unidiomatic.

    /// TODO One day, rewriting this struct using the typestate might be a

    /// good idea.

    pub fn set_all_dirs(&mut self) {

        if self.all_dirs.is_none() {

        }

    }

    pub fn set_dirs(&mut self) {

        if self.dirs.is_none() {

                Some(EntryState::Removed),

            ));

        }

    }

    pub fn has_tracked_dir(&mut self, directory: &[u8]) -> bool {

        self.set_dirs();

        self.dirs.as_ref().unwrap().contains(directory)

    }

    pub fn has_dir(&mut self, directory: &[u8]) -> bool {

        self.set_all_dirs();

        self.all_dirs.as_ref().unwrap().contains(directory)

    }

    pub fn parents(

        &mut self,

        file_contents: &[u8],

    ) -> Result<&DirstateParents, DirstateError> {

        if let Some(ref parents) = self.parents {

            return Ok(parents);

        }

        let parents;

        if file_contents.len() == PARENT_SIZE * 2 {

            parents = DirstateParents {

                p1: file_contents[..PARENT_SIZE].try_into().unwrap(),

                p2: file_contents[PARENT_SIZE..PARENT_SIZE * 2]

                    .try_into()

                    .unwrap(),

            };

        } else if file_contents.is_empty() {

            parents = DirstateParents {

                p1: NULL_ID,

                p2: NULL_ID,

            };

        } else {

            return Err(DirstateError::Parse(DirstateParseError::Damaged));

        }

        self.parents = Some(parents);

        Ok(self.parents.as_ref().unwrap())

    }

    pub fn set_parents(&mut self, parents: &DirstateParents) {

        self.parents = Some(parents.clone());

        self.dirty_parents = true;

    }

    pub fn read(

        &mut self,

        file_contents: &[u8],

    ) -> Result<Option<DirstateParents>, DirstateError> {

        if file_contents.is_empty() {

            return Ok(None);

        }

        let parents = parse_dirstate(

            &mut self.state_map,

            &mut self.copy_map,

            file_contents,

        )?;

        if !self.dirty_parents {

            self.set_parents(&parents);

        }

        Ok(Some(parents))

    }

    pub fn pack(

        &mut self,

        parents: DirstateParents,

        now: Duration,

    ) -> Result<Vec<u8>, DirstateError> {

        let packed =

            pack_dirstate(&mut self.state_map, &self.copy_map, parents, now)?;

        self.dirty_parents = false;

        let result = self.non_normal_other_parent_entries();

        self.non_normal_set = result.0;

        self.other_parent_set = result.1;

        Ok(packed)

    }

    pub fn build_file_fold_map(&mut self) -> &FileFoldMap {

        if let Some(ref file_fold_map) = self.file_fold_map {

            return file_fold_map;

        }

        let mut new_file_fold_map = FileFoldMap::new();

        for (filename, DirstateEntry { state, .. }) in self.state_map.borrow()

        {

            if *state == EntryState::Removed {

                new_file_fold_map.insert(

                    filename.to_ascii_uppercase().to_owned(),

                    filename.to_owned(),

                );

            }

        }

        self.file_fold_map = Some(new_file_fold_map);

        self.file_fold_map.as_ref().unwrap()

    }

}

#[cfg(test)]

mod tests {

    use super::*;

    #[test]

    fn test_dirs_multiset() {

        let mut map = DirstateMap::new();

        assert!(map.dirs.is_none());

        assert!(map.all_dirs.is_none());

        assert_eq!(false, map.has_dir(b"nope"));

        assert!(map.all_dirs.is_some());

        assert!(map.dirs.is_none());

        assert_eq!(false, map.has_tracked_dir(b"nope"));