powerline_git.lua

-- Constants
local segmentColors = {
    clean = {
        fill = colorGreen,
        text = colorWhite
    },
    dirty = {
        fill = colorYellow,
        text = colorBlack
    },
    conflict = {
        fill = colorRed,
        text = colorWhite
    }
}

---
-- Finds out the name of the current branch
-- @return {nil|git branch name}
---
function get_git_branch(git_dir)
    git_dir = git_dir or get_git_dir()

    -- If git directory not found then we're probably outside of repo
    -- or something went wrong. The same is when head_file is nil
    local head_file = git_dir and io.open(git_dir..'/HEAD')
    if not head_file then return end

    local HEAD = head_file:read()
    head_file:close()

    -- if HEAD matches branch expression, then we're on named branch
    -- otherwise it is a detached commit
    local branch_name = HEAD:match('ref: refs/heads/(.+)')

    return branch_name or 'HEAD detached at '..HEAD:sub(1, 7)
end

---
-- Gets the .git directory
-- copied from clink.lua
-- clink.lua is saved under %CMDER_ROOT%\vendor
-- @return {bool} indicating there's a git directory or not
---
-- function get_git_dir(path)
-- MOVED INTO CORE

---
-- Gets the status of working dir
-- @return {bool} indicating true for clean, false for dirty
---
function get_git_status()
    local file = io.popen("git --no-optional-locks status --porcelain 2>nul")
    for line in file:lines() do
        file:close()
        return false
    end
    file:close()
    return true
end

---
-- Gets the conflict status
-- @return {bool} indicating true for conflict, false for no conflicts
---
function get_git_conflict()
    local file = io.popen("git diff --name-only --diff-filter=U 2>nul")
    for line in file:lines() do
        file:close()
        return true;
    end
    file:close()
    return false
end

-- * Segment object with these properties:
---- * isNeeded: sepcifies whether a segment should be added or not. For example: no Git segment is needed in a non-git folder
---- * text
---- * textColor: Use one of the color constants. Ex: colorWhite
---- * fillColor: Use one of the color constants. Ex: colorBlue
local segment = {
    isNeeded = false,
    text = "",
    textColor = 0,
    fillColor = 0
}

---
-- Sets the properties of the Segment object, and prepares for a segment to be added
---
local function init()
    segment.isNeeded = get_git_dir()    
    if segment.isNeeded then
        -- if we're inside of git repo then try to detect current branch
        local branch = get_git_branch(git_dir)
        if branch then
            -- Has branch => therefore it is a git folder, now figure out status
            local gitStatus = get_git_status()
            local gitConflict = get_git_conflict()
            segment.text = " "..branchSymbol.." "..branch.." "


            if gitConflict then
                segment.textColor = segmentColors.conflict.text
                segment.fillColor = segmentColors.conflict.fill
                segment.text = segment.text..gitConflictSymbol
                return
            end 

            if gitStatus then
                segment.textColor = segmentColors.clean.text
                segment.fillColor = segmentColors.clean.fill
                segment.text = segment.text..""
                return
            end

            segment.textColor = segmentColors.dirty.text
            segment.fillColor = segmentColors.dirty.fill
            segment.text = segment.text.."± "
        end
    end
end 

---
-- Uses the segment properties to add a new segment to the prompt
---
local function addAddonSegment()
    init()
    if segment.isNeeded then 
        addSegment(segment.text, segment.textColor, segment.fillColor)
    end 
end 

-- Register this addon with Clink
clink.prompt.register_filter(addAddonSegment, delayGit)