#!/usr/bin/env sh
# worklog-target.sh: 產生 worklog wiki 目標頁。
# 用法:
#   worklog-target.sh <owner/repo> [hash|page|contents|all]
set -eu

usage() {
  echo 'usage: worklog-target.sh <owner/repo> [hash|page|contents|all]' >&2
  exit 2
}

[ "$#" -ge 1 ] || usage
[ "$#" -le 2 ] || usage

repo=$1
field=${2:-page}

if [ -z "$repo" ]; then
  usage
fi

if command -v sha1sum >/dev/null 2>&1; then
  raw=$(printf '%s' "$repo" | sha1sum | awk '{print $1}')
elif command -v shasum >/dev/null 2>&1; then
  raw=$(printf '%s' "$repo" | shasum -a 1 | awk '{print $1}')
else
  echo 'no SHA-1 helper found' >&2
  exit 1
fi

hash=$(printf '%s' "$raw" | cut -c1-8 | tr a-f A-F)
case "$hash" in
  [0-9ABC]*) hash="H$(printf '%s' "$hash" | cut -c1-7)" ;;
esac

page="LOG_${hash}"
contents='LOG_CONTENTS'

case "$field" in
  hash) printf '%s\n' "$hash" ;;
  page) printf '%s\n' "$page" ;;
  contents) printf '%s\n' "$contents" ;;
  all)
    printf 'HASH=%s\n' "$hash"
    printf 'PAGE=%s\n' "$page"
    printf 'CONTENTS=%s\n' "$contents"
    ;;
  *) usage ;;
esac