# vim:et sts=2 sw=2 ft=zsh
#
# Exposes Git repository information via the git_info associative array.
#

# Extended globbing is needed to parse repository status.
setopt LOCAL_OPTIONS EXTENDED_GLOB

# Clean up previous git_info.
unset git_info
typeset -gA git_info

# Return if not inside a Git repository work tree.
if ! command git rev-parse --is-inside-work-tree &>/dev/null; then
  return 1
fi

# Ignore submodule status.
local ignore_submodules
zstyle -s ':zim:git-info' ignore-submodules 'ignore_submodules' || ignore_submodules='all'

# Format stashed.
local stashed_format stashed_formatted
if zstyle -s ':zim:git-info:stashed' format 'stashed_format'; then
  local -i stashed=$(command git stash list 2>/dev/null | wc -l)
  (( stashed )) && zformat -f stashed_formatted ${stashed_format} "S:${stashed}"
fi

# Format action.
local action_format action_formatted
if zstyle -s ':zim:git-info:action' format 'action_format'; then
  local action=$(git-action)
  if [[ -n ${action} ]]; then
    zformat -f action_formatted ${action_format} "s:${action}"
  fi
fi

# The contents of git_info are subject to expansion by the shell. Avoid
# putting raw ref names in the prompt to protect the user from arbitrary code
# execution via specially crafted ref names (e.g., a ref named
# '$(IFS=_;cmd=sudo_rm_-rf_/;$cmd)' would execute 'sudo rm -rf /' when the
# prompt is drawn). Instead, put the ref names in new global variables and
# reference these variables from git_info.
# See https://github.com/njhartwell/pw3nage

# Get the branch.
__GIT_INFO_BRANCH=$(command git symbolic-ref -q --short HEAD 2>/dev/null)

local ahead_formatted behind_formatted branch_formatted commit_formatted diverged_formatted position_formatted remote_formatted
if [[ -n ${__GIT_INFO_BRANCH} ]]; then
  unset __GIT_INFO_POSITION

  # Format branch.
  local branch_format
  if zstyle -s ':zim:git-info:branch' format 'branch_format'; then
    zformat -f branch_formatted ${branch_format} 'b:${__GIT_INFO_BRANCH}'
  fi

  # Format remote.
  local remote_format
  if zstyle -s ':zim:git-info:remote' format 'remote_format'; then
    # Gets the remote name.
    local remote_cmd='command git rev-parse --symbolic-full-name --verify HEAD@{upstream}'
    __GIT_INFO_REMOTE=${$(${(z)remote_cmd} 2>/dev/null)##refs/remotes/}
    if [[ -n ${__GIT_INFO_REMOTE} ]]; then
      zformat -f remote_formatted ${remote_format} 'R:${__GIT_INFO_REMOTE}'
    else
      unset __GIT_INFO_REMOTE
    fi
  fi

  local ahead_format behind_format diverged_format
  zstyle -s ':zim:git-info:ahead' format 'ahead_format'
  zstyle -s ':zim:git-info:behind' format 'behind_format'
  zstyle -s ':zim:git-info:diverged' format 'diverged_format'
  if [[ -n ${ahead_format} || -n ${behind_format} || -n ${diverged_format} ]]; then
    # Gets the commit difference counts between local and remote.
    local ahead_and_behind_cmd='command git rev-list --count --left-right HEAD...@{upstream}'

    # Get ahead and behind counts.
    local ahead_and_behind=$(${(z)ahead_and_behind_cmd} 2>/dev/null)
    local -i ahead=${ahead_and_behind[(w)1]}
    local -i behind=${ahead_and_behind[(w)2]}

    if [[ -n ${diverged_format} && ${ahead} -gt 0 && ${behind} -gt 0 ]]; then
      # Format diverged.
      diverged_formatted=${diverged_format}
    else
      # Format ahead.
      if [[ -n ${ahead_format} && ${ahead} -gt 0 ]]; then
        zformat -f ahead_formatted ${ahead_format} "A:${ahead}"
      fi
      # Format behind.
      if [[ -n ${behind_format} && ${behind} -gt 0 ]]; then
        zformat -f behind_formatted ${behind_format} "B:${behind}"
      fi
    fi
  fi
else
  unset __GIT_INFO_BRANCH
  unset __GIT_INFO_REMOTE

  # Format commit.
  local commit_format
  if zstyle -s ':zim:git-info:commit' format 'commit_format'; then
    local commit=$(command git rev-parse --short HEAD 2>/dev/null)
    if [[ -n ${commit} ]]; then
      zformat -f commit_formatted ${commit_format} "c:${commit}"
    fi
  fi

  # Format position.
  local position_format
  if zstyle -s ':zim:git-info:position' format 'position_format'; then
    __GIT_INFO_POSITION=$(command git describe --contains --all HEAD 2>/dev/null)
    if [[ -n ${__GIT_INFO_POSITION} ]]; then
      zformat -f position_formatted ${position_format} 'p:${__GIT_INFO_POSITION}'
    fi
  fi
fi

# Dirty and clean format.
local dirty_format dirty_formatted clean_format clean_formatted
zstyle -s ':zim:git-info:dirty' format 'dirty_format'
zstyle -s ':zim:git-info:clean' format 'clean_format'

local -i dirty
local indexed_formatted unindexed_formatted untracked_formatted
if ! zstyle -t ':zim:git-info' verbose; then
  # Format unindexed.
  local unindexed_format
  zstyle -s ':zim:git-info:unindexed' format 'unindexed_format'
  if [[ -n ${unindexed_format} || -n ${dirty_format} || -n ${clean_format} ]]; then
    if ! command git diff-files --no-ext-diff --quiet --ignore-submodules=${ignore_submodules} &>/dev/null; then
      unindexed_formatted=${unindexed_format}
      dirty=1
    fi
  fi

  # Format indexed.
  local indexed_format
  zstyle -s ':zim:git-info:indexed' format 'indexed_format'
  if [[ -n ${indexed_format} || (${dirty} -eq 0 && (-n ${dirty_format} || -n ${clean_format})) ]]; then
    if ! command git diff-index --no-ext-diff --quiet --cached --ignore-submodules=${ignore_submodules} HEAD &>/dev/null; then
      indexed_formatted=${indexed_format}
      dirty=1
    fi
  fi

  # Format dirty and clean.
  if (( dirty )); then
    dirty_formatted=${dirty_format}
  else
    clean_formatted=${clean_format}
  fi
else
  # Use porcelain status for easy parsing.
  local status_cmd="command git status --porcelain --ignore-submodules=${ignore_submodules}"

  local -i indexed unindexed untracked
  # Get current status.
  while IFS=$'\n' read line; do
    if [[ ${line:0:2} == '??' ]]; then
      (( untracked++ ))
    else
      [[ ${line:0:1} != ' ' ]] && (( indexed++ ))
      [[ ${line:1:1} != ' ' ]] && (( unindexed++ ))
    fi
    (( dirty++ ))
  done < <(${(z)status_cmd} 2>/dev/null)

  # Format indexed.
  if (( indexed )); then
    local indexed_format
    zstyle -s ':zim:git-info:indexed' format 'indexed_format'
    zformat -f indexed_formatted ${indexed_format} "i:${indexed}"
  fi

  # Format unindexed.
  if (( unindexed )); then
    local unindexed_format
    zstyle -s ':zim:git-info:unindexed' format 'unindexed_format'
    zformat -f unindexed_formatted ${unindexed_format} "I:${unindexed}"
  fi

  # Format untracked.
  if (( untracked )); then
    local untracked_format
    zstyle -s ':zim:git-info:untracked' format 'untracked_format'
    zformat -f untracked_formatted ${untracked_format} "u:${untracked}"
  fi

  # Format dirty and clean.
  if (( dirty )); then
    zformat -f dirty_formatted ${dirty_format} "u:${dirty}"
  else
    clean_formatted=${clean_format}
  fi
fi

# Format info.
local -A info_formats
local info_format reply
zstyle -a ':zim:git-info:keys' format 'info_formats'
for info_format in ${(k)info_formats}; do
  zformat -f reply "${info_formats[${info_format}]}" \
    "A:${ahead_formatted}" \
    "B:${behind_formatted}" \
    "b:${branch_formatted}" \
    "C:${clean_formatted}" \
    "c:${commit_formatted}" \
    "D:${dirty_formatted}" \
    "i:${indexed_formatted}" \
    "I:${unindexed_formatted}" \
    "p:${position_formatted}" \
    "R:${remote_formatted}" \
    "s:${action_formatted}" \
    "S:${stashed_formatted}" \
    "u:${untracked_formatted}" \
    "V:${diverged_formatted}"
  git_info[${info_format}]=${reply}
done

return 0