Oh My Zsh theme that mimics the behavior of posh-git

posh-git.zsh-theme

# Colors
local RED="%F{red}"
local GREEN="%F{green}"
local BLUE="%F{blue}"
local YELLOW="%F{yellow}"
local MAGENTA="%F{magenta}"
local CYAN="%F{cyan}"
local RESET="%f"

# Symbols
local GIT_CLEAN="≡"
local GIT_BEHIND="↓"
local GIT_AHEAD="↑"

# Function to get the Git status
git_prompt_info() {
  # Check if we're in a Git repository
  if git rev-parse --is-inside-work-tree >/dev/null 2>&1; then
    # Get the current branch name
    local branch=$(git rev-parse --abbrev-ref HEAD 2>/dev/null)
    [[ "$branch" == "HEAD" ]] && branch="(detached)"

    # Get the status of the working directory
    local git_status=$(git status --short --branch 2>/dev/null)

    if [[ "$git_status" == *...* ]]; then
      remoteStatus=" "
      if [[ "$git_status" =~ "ahead ([0-9]+)" ]]; then
        remoteStatus+="${GIT_AHEAD}${match[1]}"
      fi
      if [[ "$git_status" =~ "behind ([0-9]+)" ]]; then
        remoteStatus+="${GIT_BEHIND}${match[1]}"
      fi
      if [[ "$remoteStatus" = " " ]]; then
        remoteStatus+="${GIT_CLEAN}"
      fi
    else
      remoteStatus=""
    fi
    
    # Set the color of the branch name based on the status
    if [[ "$remoteStatus" == *"${GIT_AHEAD}"* ]] && [[ "$remoteStatus" == *"${GIT_BEHIND}"* ]]; then
      branch="${YELLOW}${branch}"
    elif [[ "$remoteStatus" == *"${GIT_AHEAD}"* ]]; then
      branch="${GREEN}${branch}"
    elif [[ "$remoteStatus" == *"${GIT_BEHIND}"* ]]; then
      branch="${RED}${branch}"
    else
      branch="${CYAN}${branch}"
    fi

    # Check for file changes and add symbols
    local stagedChanges=$(echo "$git_status" | grep -E '^M' | wc -l | tr -d ' ')
    local unstagedChanges=$(echo "$git_status" | grep -E '^ M' | wc -l | tr -d ' ')
    local stagedAdds=$(echo "$git_status" | grep -E '^A' | wc -l | tr -d ' ')
    local unstagedAdds=$(echo "$git_status" | grep -E '^\?\?' | wc -l | tr -d ' ')
    local stagedDeletes=$(echo "$git_status" | grep -E '^D' | wc -l | tr -d ' ')
    local unstagedDeletes=$(echo "$git_status" | grep -E '^ D' | wc -l | tr -d ' ')
 
    if [[ "$stagedChanges" -ne 0 || "$stagedAdds" -ne 0 || "$stagedDeletes" -ne 0 ]]; then
        staged=" ${GREEN}~${stagedChanges} +${stagedAdds} -${stagedDeletes}"
    fi
    if [[ "$unstagedChanges" -ne 0 || "$unstagedAdds" -ne 0 || "$unstagedDeletes" -ne 0 ]]; then
        unstaged=" ${RED}~${unstagedChanges} +${unstagedAdds} -${unstagedDeletes}"
    fi
    if [[ -n "$staged" && -n "$unstaged" ]]; then
        separator="${YELLOW} |"
    fi

    echo -n " ${YELLOW}[${branch}${remoteStatus}${staged}${separator}${unstaged}${YELLOW}]"
  fi
}


# Prompt definition
PROMPT='${GREEN}%n@%m${RESET}:${BLUE}%~$(git_prompt_info)${RESET}%# '