#!/bin/bash

# Bash unofficial strict mode
set -euo pipefail
# http://www.dwheeler.com/essays/filenames-in-shell.html
IFS=$'\n\t'

function define() { IFS='\n' read -r -d '' ${1} || true; }

define TMPL << 'EOF'
{
  "commit": "%H",
  "tree": "%T",
  "parent": "%P",
  "refs": "%D",
  "encoding": "%e",
  "message": "MSG",
  "commit_notes": "%N",
  "verification_flag": "%G?",
  "signer": "%GS",
  "signer_key": "%GK",
  "author": {
    "name": "AUTHOR",
    "email": "%aE",
    "date": "%ai"
  },
  "commiter": {
    "name": "COMMITER",
    "email": "%cE",
    "date": "%ci"
  }
}
EOF

function strip () {
  # strip newlines then strip all whitespace
  sed -e :a -e '/./,$!d;/^\n*$/{$d;N;};/\n$/ba' | sed -E 's/^\s+|\s+$//g'
}

function sanitize () {
  # escape newline, escape quotes, escape backslash, escape tabs, fix double escapes, delete invalid characters
  sed ':a;N;$!ba;s/\n/\\n/g' | sed 's/"/\\"/g' | sed 's/\\\\/\\/g' | sed 's/\t/\\t/g' | sed -E 's/\\([^nt"])/\\\\\1/g' | tr -d '\r\0\t' | sed -E 's/[\x00-\x1f]//g';
}

function field () {
  git show -s --format="$1" "$2" | strip | sanitize
}

git log --pretty=format:'%H' | while IFS='' read -r hash; do
  TMP="$TMPL"
  TMP="${TMP/MSG/$(field "%B" $hash)}"
  TMP="${TMP/AUTHOR/$(field "%aN" $hash)}"
  TMP="${TMP/COMMITER/$(field "%cN" $hash)}"
  git show $hash -s --format="$TMP"
done
# | sed ':a;N;$!ba;s/\n/\\n/g' | sed 's/\x0\x0\x0/\0\0\n/g' |  sed 's/\"/\\\"/g' | sed 's/\x0\x0/"/g' | sed 's/\x0/" "/g' | tr -d '\000' \
# | xargs printf '{"commit": "%s","abbreviated_commit": "%s","tree": "%s","abbreviated_tree": "%s","parent": "%s","abbreviated_parent": "%s","refs": "%s","encoding": "%s","subject": "%s","sanitized_subject_line": "%s","body": "%s","commit_notes": "%s","verification_flag": "%s","signer": "%s","signer_key": "%s","author": {"name": "%s","email": "%s","date": "%s"},"commiter": {"name": "%s","email": "%s","date": "%s"}}\n'

# | sed "$ s/,$//" | sed ':a;N;$!ba;s/\r\n\([^{]\)/\\n\1/g'| awk 'BEGIN { print("[") } { print(%s) } END { print("]") }' | sed ':a;N;$!ba;s/\n/ /g'