#!/usr/bin/env bash

set -euo

DEFAULT_CONFIG_PATH=.

# Read default configs from default config file
. "${DEFAULT_CONFIG_PATH}"/default-config.ini

# Read custom configs from custom config file
. "${DEFAULT_CONFIG_PATH}"/config.d/*.ini

# For each lifecycle rule, execute a movement using rsync
start_movement () {
  SOURCE_PATH=$1
  DESTINATION_PATH=$2
  AMINS=$3
  find "$SOURCE_PATH" \
    ! -type l \
    -type f \
    -amin +"$AMINS" \
    -printf "%P\0" | \
  rsync -0 \
      --inplace \
      --archive \
      --mkpath \
      --files-from=- \
      "$SOURCE_PATH" \
      "$DESTINATION_PATH"
}
MOVEMENT_JSON_PATH=$( readlink -f "${DEFAULT_CONFIG_PATH}/movement.json" )
if ! [[ -f ${MOVEMENT_JSON_PATH} ]]; then
  echo "Missing movement file. Exiting."
  exit 1
fi
RULE_LENGTH=$( jq '.movements | length' "${MOVEMENT_JSON_PATH}" )
for (( i=0; i<$RULE_LENGTH ; i++ ))
do
  SOURCE_PATH=$( jq -r ".movements[$i].sourcePath" "${MOVEMENT_JSON_PATH}" )
  DESTINATION_PATH=$( jq -r ".movements[$i].destinationPath" "${MOVEMENT_JSON_PATH}" )
  AMINS=$( jq -r ".movements[$i].amins" "${MOVEMENT_JSON_PATH}" )
  start_movement "$SOURCE_PATH" "$DESTINATION_PATH" "$AMINS"
done

# Run checks and build soft links
if ! [[ -d ${MAP_ROOT_DIRECTORY} ]]; then
  echo "Missing root directory"
  exit 1
fi
GREEN_PATH=$( readlink -f "${MAP_ROOT_DIRECTORY}"/green )
RED_PATH=$( readlink -f "${MAP_ROOT_DIRECTORY}"/red )
BLUE_PATH=$( readlink -f "${MAP_ROOT_DIRECTORY}"/blue )
export GREEN_PATH
if ! [[ -d ${GREEN_PATH} ]]; then
  mkdir "${GREEN_PATH}"
fi

# Compile storage paths from all the movements
readarray -t STORAGE_PATHS \
  < <( jq -r '.movements[] | .sourcePath, .destinationPath' "${MOVEMENT_JSON_PATH}" | xargs -n 1 -I {} readlink -e "{}" | sort --unique )

# Build folder structure
printf '%s\0' "${STORAGE_PATHS[@]}" | \
  xargs -0 -n 1 bash -c 'find "$0" -type d -printf "%P\0"' | \
  sort --unique --zero-terminated | \
  parallel -0 mkdir -p "${GREEN_PATH}"/{}

# Build file structure using soft links
link_file () {
  echo "\$1 $1"
  echo "\$2 $2"
  echo "\$3 $3"
  echo "Soft linked to ${1/$2/$3}"
  /usr/bin/ln -s "$1" "${1/$2/$3}" 
}
export -f link_file
for STORAGE_PATH in "${STORAGE_PATHS[@]}"
do
  find "${STORAGE_PATH}" -type f -print0 | \
  sort --unique --zero-terminated | \
  parallel -0 link_file "{}" "${STORAGE_PATH}" "${GREEN_PATH}"
done

# Swap blue/green
rm -rf "${RED_PATH}" && \
mv "${BLUE_PATH}" "${RED_PATH}" && \
mv "${GREEN_PATH}" "${BLUE_PATH}"