fzgit

#!/usr/bin/env bash

declare -A aliases
declare -A helptext
declare -r c_reset=$(tput sgr0)
declare -r c_red=$(tput setaf 1)
declare -r c_green=$(tput setaf 2)
declare -r c_yellow=$(tput setaf 3)
declare -r c_grey=$(tput setaf 8)

err() {
  printf "${c_red}%s${c_reset}\n" "$*" >&2
}

die() {
  if (( $# > 0 )); then
    err "$@"
  fi
  exit 1
}

has() {
  local v c
  if [[ $1 = '-v' ]]; then
    v=1
    shift
  fi
  for c; do c="${c%% *}"
    if ! command -v "$c" &> /dev/null; then
      (( v > 0 )) && err "$c not found"
      return 1
    fi
  done
}

aliases[-h]=help
aliases[--help]=help
helptext[help]='show this help'
subcmd_help() {
  local formattedhelptext

  formattedhelptext=$(for c in "${subcmds_avail[@]}"; do
    printf "  %s\n    %s\n" "$c" "${helptext[$c]}"
  done)
  LESS=-FEXR less <<-HELP
$0 <COMMAND>

${formattedhelptext}
HELP
}

fzf() {
  local prompt
  if [[ $1 == --prompt=* ]]; then
    prompt="${1##*=}>"
    shift
  fi
  branch=$(git rev-parse --abbrev-ref HEAD)
  opts=( --prompt="fzgit${branch}>${prompt} " )
  [[ -v FZGIT_OPTIONS ]] && opts=( $FZGIT_OPTIONS )
  command fzf "${opts[@]}" \
    --inline-info \
    --ansi \
    --no-clear \
    "$@"
}

helptext[diff]='Show changes between commits, commit and working tree, etc'
subcmd_diff() {
  if (( $# > 0 )); then git diff "$@"; return; fi
  fzf \
    --bind='start:reload:git -c color.status=always status -su' \
    --nth=2.. \
    --preview='git diff --color=always {2..} | delta -w $FZF_PREVIEW_COLUMNS' \
    --bind='enter:execute:git diff --color=always {2..}' \
    --preview-window=70%
}

helptext[add]='Add file contents to the index'
subcmd_add() {
  if (( $# > 0 )); then git add "$@"; return; fi
  local diff
  diff=$(git diff --color=always | perl -pwe 's/^(\e\[[0-9;]*m)*(?=diff)/\0/m' | fzf --read0)
  [[ -z $diff ]] && return
  git apply --check --cached <<< "$diff" &&
    git apply --cached <<< "$diff" &&
    git apply --stat <<< "$diff"
  subcmd_add
}

helptext[status]='Show the working tree status'
subcmd_status() {
  local preview='git diff --color=always {2..}'
  fzf \
    --nth=2.. \
    --bind='start:reload:git -c color.status=always status -s' \
    --preview="$preview" \
    --bind='enter:execute:git add -p {2..}'
}

helptext[checkout]='Checkout a branch or paths to the working tree'
subcmd_checkout() { # {{{
  local list response key branch header
  if (( $# > 0 )); then git checkout "$@"; return; fi
  {
    git branch --all --color -vv
    git tag
  } |
    fzf --prompt='checkout' \
    --header="$header" \
    --bind=enter:execute:"git checkout \$(perl -pe 's/^\*?\s*(remotes\/[^\/]*\/)?([^ ]+).*/\2/' <<< {})"

}

helptext[stash-ls]='List the stash entries that you currently have'
subcmd_stash-ls() {
  if (( $# > 0 )); then git stash "$@"; return; fi
  local header='use ctrl-d to show a diff or ctrl-b to create a new branch'
  git stash list --pretty="%C(yellow)%h %>(14)%Cgreen%cr %C(blue)%gs" |
    fzf --prompt='stash' --no-sort --header="$header" \
    --bind='ctrl-d:execute: git diff {1} --color=always | less -R' \
    --bind='ctrl-b:execute(git stash branch "stash-{1}" {1})+abort' \
    --preview='git diff --color {1}'
}

has -v fzf perl git || die

mapfile -t subcmds_avail < <(compgen -A function | awk '/^subcmd_/ { sub(/^subcmd_/, "", $0); print }')

nocmd() {
  local cmd
  cmd=$(for c in "${subcmds_avail[@]}"; do
  printf "$c\t${help}\t${helptext[$c]}\n"
done)
  cmd=$(column -t -s $'\t' <<< "$cmd" | fzf | awk '{print $1}')
  if [[ -n $cmd ]]; then
    subcmd_$cmd
  else
    exit 1
  fi
}


if (( $# < 1 )); then
  nocmd
  exit 1
elif has "subcmd_$1"; then
  subcmd="subcmd_$1"
  shift
  "$subcmd" "$@"
elif [[ -v aliases[$1] ]]; then
  subcmd=subcmd_${aliases[$1]}
  shift
  "$subcmd" "$@"
else
  exec git "$@"
fi