// dirstate module

//

// 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::errors::HgError;

use crate::revlog::Node;

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

use bytes_cast::{unaligned, BytesCast};

use std::convert::TryFrom;

pub mod dirs_multiset;

pub mod dirstate_map;

pub mod parsers;

pub mod status;

#[derive(Debug, PartialEq, Clone, BytesCast)]

#[repr(C)]

pub struct DirstateParents {

    pub p1: Node,

    pub p2: Node,

}

/// The C implementation uses all signed types. This will be an issue

/// either when 4GB+ source files are commonplace or in 2038, whichever

/// comes first.

#[derive(Debug, PartialEq, Copy, Clone)]

pub struct DirstateEntry {

    pub state: EntryState,

    pub mode: i32,

    pub mtime: i32,

    pub size: i32,

}

#[derive(BytesCast)]

#[repr(C)]

struct RawEntry {

    state: u8,

    mode: unaligned::I32Be,

    size: unaligned::I32Be,

    mtime: unaligned::I32Be,

    length: unaligned::I32Be,

}

/// A `DirstateEntry` with a size of `-2` means that it was merged from the

/// other parent. This allows revert to pick the right status back during a

/// merge.

pub const SIZE_FROM_OTHER_PARENT: i32 = -2;

pub type StateMap = FastHashMap<HgPathBuf, DirstateEntry>;

pub type StateMapIter<'a> =

    Box<dyn Iterator<Item = (&'a HgPathBuf, &'a DirstateEntry)> + Send + 'a>;

pub type CopyMap = FastHashMap<HgPathBuf, HgPathBuf>;

pub type CopyMapIter<'a> =

    Box<dyn Iterator<Item = (&'a HgPathBuf, &'a HgPathBuf)> + Send + 'a>;

#[derive(Copy, Clone, Debug, Eq, PartialEq)]

pub enum EntryState {

    Normal,

    Added,

    Removed,

    Merged,

    Unknown,

}

impl TryFrom<u8> for EntryState {

    type Error = HgError;

    fn try_from(value: u8) -> Result<Self, Self::Error> {

        match value {

            b'n' => Ok(EntryState::Normal),

            b'a' => Ok(EntryState::Added),

            b'r' => Ok(EntryState::Removed),

            b'm' => Ok(EntryState::Merged),

            b'?' => Ok(EntryState::Unknown),

            _ => Err(HgError::CorruptedRepository(format!(

                "Incorrect dirstate entry state {}",

                value

            ))),

        }

    }

}

impl Into<u8> for EntryState {

    fn into(self) -> u8 {

        match self {

            EntryState::Normal => b'n',

            EntryState::Added => b'a',

            EntryState::Removed => b'r',

            EntryState::Merged => b'm',

            EntryState::Unknown => b'?',

        }

    }

}