gen-gh-permalink

#!/bin/sh

#- Constructs github permalinks given filename and line number or range of lines.
#- Formats them as `[src/file.js:3](...)` markdown link and inserts into clipboard
#- ```sh
#- gen-gh-permalink src/file.js 3 4
#- ```
#-
#- You can use `-s`/`--snippet` parameter and pipe a piece of code into this script to get
#- ````markdown
#- [src/file.js:3](...):
#- ```js
#- const a = 3;
#- ...
#- ```
#- ````
#- -style snippet.
#-
#- Useful vim bindings:
#- ```vim
#- nnoremap gH :execute '!' . 'gen-gh-permalink ' . shellescape(expand('%')) . ' ' . line(".")<cr>
#- vnoremap gH <esc>:execute '!' . 'gen-gh-permalink ' . shellescape(expand('%')) . ' ' . getpos("'<")[1] . ' ' . getpos("'>")[1]<cr>
#- vnoremap gHH <esc>:execute "'<,'>w !" . 'gen-gh-permalink -s ' . shellescape(expand('%')) . ' ' . getpos("'<")[1] . ' ' . getpos("'>")[1]<cr>
#- ```
#-
#* xclip git sed grep

if [ "$1" = '-s' ] || [ "$1" = '--snippet' ]; then
  snippet=true
  shift
fi

fname="$1"
l1=$2
l2=$3

abs_fname="$PWD/$fname"

cd "$(dirname "$fname")"
# git rev-parse --git-dir || return 0
gitdir=$(git rev-parse --show-toplevel) && [ ! -z $? ] || exit 1
rel_fname="${abs_fname#"$gitdir/"}"

if [ $l1 = "$l2" ]; then
  l2=''
fi

if [ ! -z "$(git diff --name-only "$abs_fname")" ]; then
  echo "File $fname contains changes. Stash them and try again"
  exit 1
fi

origin=$(git remote get-url origin)

if [ -z $(echo "$origin" | grep 'github.com') ]; then
  echo "Not implemented: origin is not github"
  exit 1
fi

repo=$(echo $origin | sed 's/^\(git@github.com:\|https:\/\/github.com\/\)\([a-zA-Z_-]\+\)\/\([a-zA-Z_-]\+\)\.git$/\2\/\3/')

if [ "$origin" = "$repo" ]; then
  echo "Invalid origin"
  exit 1
fi

commit=$(git rev-parse HEAD)
if [ -z "$l2" ]; then
  l2mb=''
else
  l2mb="-L$l2"
fi

link="https://github.com/$repo/blob/$commit/$rel_fname#L${l1}${l2mb}"

path="$rel_fname:$l1"

(
  echo -n "[$path]($link)"
  if [ ! -z "$snippet" ]; then
    echo ':'
    echo '```'"${abs_fname##*.}"
    cat
    echo '```'
  fi
) | xclip -i -selection clipboard