#!/bin/sh

# Settings
CSV_URL="https://www8.cao.go.jp/chosei/shukujitsu/syukujitsu.csv"

# Constants
EXIT_SUCCESS=0
EXIT_FAILURE=1

# Verify the required runtime environment
if ! command -v curl >/dev/null; then
  echo "This script requires \"curl\" to be installed. Please install it and try again."
  exit $EXIT_FAILURE
fi
if ! command -v nkf >/dev/null; then
  echo "This script requires \"nkf\" to be installed. Please install it and try again."
  exit $EXIT_FAILURE
fi

# Logging
CURRENT_MONTH=$(date "+%Yw%U%z")
SCRIPT_NAME=$(basename $0)
LOG_DIR="log"
LOG_FILE="$LOG_DIR/$SCRIPT_NAME_$CURRENT_MONTH"

get_current_time() {
  date "+%Y-%m-%d %H:%M:%S%z"
}

log() {
  local timestamp=$(get_current_time)
  local message=$1
  echo "$timestamp $message" >>$LOG_FILE
}

# Acquire the lock or exit
LOCK_DIR="lock"
if ! mkdir "$LOCK_DIR" 2>/dev/null; then
  echo "Another process is holding the lock. Exiting."
  exit $EXIT_FAILURE
fi

mkdir -p $LOG_DIR

# Internal configuration settings
TMP_CSV_FILE="holidays-jp-tmp.csv"
RAW_CSV_FILE="holidays-jp-raw.csv"
CSV_FILE="holidays-jp.csv"

# Run
curl -sS -L -o $TMP_CSV_FILE $CSV_URL
if ! diff -q $RAW_CSV_FILE $TMP_CSV_FILE >/dev/null 2>&1; then
  mv $TMP_CSV_FILE $RAW_CSV_FILE
  nkf -w $RAW_CSV_FILE >$CSV_FILE
  log "Changed"
else
  log "No Change"
  rm $TMP_CSV_FILE
fi

# Release the lock
rmdir "$LOCK_DIR"

# Exit
exit $EXIT_SUCCESS