use std::path::PathBuf;

use crate::dirstate::parsers::Timestamp;

use crate::dirstate_tree::on_disk::DirstateV2ParseError;

use crate::matchers::Matcher;

use crate::utils::hg_path::{HgPath, HgPathBuf};

use crate::DirstateEntry;

use crate::DirstateError;

use crate::DirstateParents;

use crate::DirstateStatus;

use crate::PatternFileWarning;

use crate::StatusError;

use crate::StatusOptions;

/// `rust/hg-cpython/src/dirstate/dirstate_map.rs` implements in Rust a

/// `DirstateMap` Python class that wraps `Box<dyn DirstateMapMethods + Send>`,

/// a trait object of this trait. Except for constructors, this trait defines

/// all APIs that the class needs to interact with its inner dirstate map.

///

/// A trait object is used to support two different concrete types:

///

/// * `rust/hg-core/src/dirstate/dirstate_map.rs` defines the "flat dirstate

///   map" which is based on a few large `HgPath`-keyed `HashMap` and `HashSet`

///   fields.

/// * `rust/hg-core/src/dirstate_tree/dirstate_map.rs` defines the "tree

///   dirstate map" based on a tree data struture with nodes for directories

///   containing child nodes for their files and sub-directories. This tree

///   enables a more efficient algorithm for `hg status`, but its details are

///   abstracted in this trait.

///

/// The dirstate map associates paths of files in the working directory to

/// various information about the state of those files.

pub trait DirstateMapMethods {

    /// Remove information about all files in this map

    fn clear(&mut self);

    /// Add the given filename to the map if it is not already there, and

    /// associate the given entry with it.

    fn set_entry(

        &mut self,

        filename: &HgPath,

        entry: DirstateEntry,

    ) -> Result<(), DirstateV2ParseError>;

    /// Add or change the information associated to a given file.

    fn add_file(

        &mut self,

        filename: &HgPath,

        entry: DirstateEntry,

    ) -> Result<(), DirstateError>;

    /// Mark a file as "removed" (as in `hg rm`).

    fn remove_file(

        &mut self,

        filename: &HgPath,

        in_merge: bool,

    ) -> Result<(), DirstateError>;

    /// Drop information about this file from the map if any.

    ///

    /// `get` will now return `None` for this filename.

    fn drop_entry_and_copy_source(

        &mut self,

        filename: &HgPath,

    ) -> Result<(), DirstateError>;

    /// Returns whether the sub-tree rooted at the given directory contains any

    /// tracked file.

    ///

    /// A file is tracked if it has a `state` other than `EntryState::Removed`.

    fn has_tracked_dir(

        &mut self,

        directory: &HgPath,

    ) -> Result<bool, DirstateError>;

    /// Returns whether the sub-tree rooted at the given directory contains any

    /// file with a dirstate entry.

    fn has_dir(&mut self, directory: &HgPath) -> Result<bool, DirstateError>;

    /// Clear mtimes equal to `now` in entries with `state ==

    /// EntryState::Normal`, and serialize bytes to write the `.hg/dirstate`

    /// file to disk in dirstate-v1 format.

    fn pack_v1(

        &mut self,

        parents: DirstateParents,

        now: Timestamp,

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

    /// Clear mtimes equal to `now` in entries with `state ==

    /// EntryState::Normal`, and serialize  bytes to write a dirstate data file

    /// to disk in dirstate-v2 format.

    ///

    /// Returns new data and metadata 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).

    ///

    /// Note: this is only supported by the tree dirstate map.

    fn pack_v2(

        &mut self,

        now: Timestamp,

        can_append: bool,

    ) -> Result<(Vec<u8>, Vec<u8>, bool), DirstateError>;

    /// Run the status algorithm.

    ///

    /// This is not sematically a method of the dirstate map, but a different

    /// algorithm is used for the flat v.s. tree dirstate map so having it in

    /// this trait enables the same dynamic dispatch as with other methods.

    fn status<'a>(

        &'a mut self,

        matcher: &'a (dyn Matcher + Sync),

        root_dir: PathBuf,

        ignore_files: Vec<PathBuf>,

        options: StatusOptions,

    ) -> Result<(DirstateStatus<'a>, Vec<PatternFileWarning>), StatusError>;

    /// Returns how many files in the dirstate map have a recorded copy source.

    fn copy_map_len(&self) -> usize;

    /// Returns an iterator of `(path, copy_source)` for all files that have a

    /// copy source.

    fn copy_map_iter(&self) -> CopyMapIter<'_>;

    /// Returns whether the givef file has a copy source.

    fn copy_map_contains_key(

        &self,

        key: &HgPath,

    ) -> Result<bool, DirstateV2ParseError>;

    /// Returns the copy source for the given file.

    fn copy_map_get(

        &self,

        key: &HgPath,

    ) -> Result<Option<&HgPath>, DirstateV2ParseError>;

    /// Removes the recorded copy source if any for the given file, and returns

    /// it.

    fn copy_map_remove(

        &mut self,

        key: &HgPath,

    ) -> Result<Option<HgPathBuf>, DirstateV2ParseError>;

    /// Set the given `value` copy source for the given `key` file.

    fn copy_map_insert(

        &mut self,

        key: HgPathBuf,

        value: HgPathBuf,

    ) -> Result<Option<HgPathBuf>, DirstateV2ParseError>;

    /// Returns the number of files that have an entry.

    fn len(&self) -> usize;

    /// Returns whether the given file has an entry.

    fn contains_key(&self, key: &HgPath)

        -> Result<bool, DirstateV2ParseError>;

    /// Returns the entry, if any, for the given file.

    fn get(

        &self,

        key: &HgPath,

    ) -> Result<Option<DirstateEntry>, DirstateV2ParseError>;

    /// Returns a `(path, entry)` iterator of files that have an entry.

    ///

    /// Because parse errors can happen during iteration, the iterated items

    /// are `Result`s.

    fn iter(&self) -> StateMapIter<'_>;

    /// Returns an iterator of tracked directories.

    ///

    /// This is the paths for which `has_tracked_dir` would return true.

    /// Or, in other words, the union of ancestor paths of all paths that have

    /// an associated entry in a "tracked" state in this dirstate map.

    ///

    /// Because parse errors can happen during iteration, the iterated items

    /// are `Result`s.

    fn iter_tracked_dirs(

        &mut self,

    ) -> Result<

        Box<

            dyn Iterator<Item = Result<&HgPath, DirstateV2ParseError>>

                + Send

                + '_,

        >,

        DirstateError,

    >;

    /// Return an iterator of `(path, (state, mode, size, mtime))` for every

    /// node stored in this dirstate map, for the purpose of the `hg

    /// debugdirstate` command.

    ///

    /// If `all` is true, include  nodes that don’t have an entry.

    /// For such nodes `state` is the ASCII space.

    /// An `mtime` may still be present. It is used to optimize `status`.

    ///

    /// Because parse errors can happen during iteration, the iterated items

    /// are `Result`s.

    fn debug_iter(

        &self,

        all: bool,

    ) -> Box<

        dyn Iterator<

                Item = Result<

                    (&HgPath, (u8, i32, i32, i32)),

                    DirstateV2ParseError,

                >,

            > + Send

            + '_,

    >;

}