#!/bin/bash

# Manage a fail of the script
#
# [internal]
#
# usage: 
# ynh_exit_properly is used only by the helper ynh_abort_if_errors.
# You should not use it directly.
# Instead, add to your script:
# ynh_clean_setup () {
#        instructions...
# }
#
# This function provide a way to clean some residual of installation that not managed by remove script.
#
# It prints a warning to inform that the script was failed, and execute the ynh_clean_setup function if used in the app script
#
ynh_exit_properly () {
	local exit_code=$?
	if [ "$exit_code" -eq 0 ]; then
			exit 0	# Exit without error if the script ended correctly
	fi

	trap '' EXIT	# Ignore new exit signals
	set +eu	# Do not exit anymore if a command fail or if a variable is empty

	echo -e "!!\n  $app's script has encountered an error. Its execution was cancelled.\n!!" >&2

	if type -t ynh_clean_setup > /dev/null; then	# Check if the function exist in the app script.
		ynh_clean_setup	# Call the function to do specific cleaning for the app.
	fi

	ynh_die	# Exit with error status
}

# Exits if an error occurs during the execution of the script.
#
# usage: ynh_abort_if_errors
#
# This configure the rest of the script execution such that, if an error occurs
# or if an empty variable is used, the execution of the script stops
# immediately and a call to `ynh_clean_setup` is triggered if it has been
# defined by your script.
#
ynh_abort_if_errors () {
	set -eu	# Exit if a command fail, and if a variable is used unset.
	trap ynh_exit_properly EXIT	# Capturing exit signals on shell script
}

# Fetch the Debian release codename
#
# usage: ynh_get_debian_release
# | ret: The Debian release codename (i.e. jessie, stretch, ...)
ynh_get_debian_release () {
	echo $(lsb_release --codename --short)
}

# Start (or other actions) a service,  print a log in case of failure and optionnaly wait until the service is completely started
#
# usage: ynh_systemd_action [-n service_name] [-a action] [ [-l "line to match"] [-p log_path] [-t timeout] [-e length] ]
# | arg: -n, --service_name= - Name of the service to reload. Default : $app
# | arg: -a, --action=       - Action to perform with systemctl. Default: start
# | arg: -l, --line_match=   - Line to match - The line to find in the log to attest the service have finished to boot.
#                              If not defined it don't wait until the service is completely started.
#                              WARNING: When using --line_match, you should always add `ynh_clean_check_starting` into your
#                                `ynh_clean_setup` at the beginning of the script. Otherwise, tail will not stop in case of failure
#                                of the script. The script will then hang forever.
# | arg: -p, --log_path=     - Log file - Path to the log file. Default : /var/log/$app/$app.log
# | arg: -t, --timeout=      - Timeout - The maximum time to wait before ending the watching. Default : 300 seconds.
# | arg: -e, --length=       - Length of the error log : Default : 20
ynh_systemd_action() {
    # Declare an array to define the options of this helper.
    declare -Ar args_array=( [n]=service_name= [a]=action= [l]=line_match= [p]=log_path= [t]=timeout= [e]=length= )
    local service_name
    local action
    local line_match
    local length
    local log_path
    local timeout

    # Manage arguments with getopts
    ynh_handle_getopts_args "$@"

    local service_name="${service_name:-$app}"
    local action=${action:-start}
    local log_path="${log_path:-/var/log/$service_name/$service_name.log}"
    local length=${length:-20}
    local timeout=${timeout:-300}

    # Start to read the log
    if [[ -n "${line_match:-}" ]]
    then
        local templog="$(mktemp)"
        # Following the starting of the app in its log
        if [ "$log_path" == "systemd" ] ; then
            # Read the systemd journal
            journalctl --unit=$service_name --follow --since=-0 --quiet > "$templog" &
            # Get the PID of the journalctl command
            local pid_tail=$!
        else
            # Read the specified log file
            tail -F -n0 "$log_path" > "$templog" 2>&1 &
            # Get the PID of the tail command
            local pid_tail=$!
        fi
    fi

    ynh_print_info --message="${action^} the service $service_name"
    systemctl $action $service_name \
        || ( journalctl --no-pager --lines=$length -u $service_name >&2 \
        ; test -e "$log_path" && echo "--" >&2 && tail --lines=$length "$log_path" >&2 \
        ; false )

    # Start the timeout and try to find line_match
    if [[ -n "${line_match:-}" ]]
    then
        local i=0
        for i in $(seq 1 $timeout)
        do
            # Read the log until the sentence is found, that means the app finished to start. Or run until the timeout
            if grep --quiet "$line_match" "$templog"
            then
                ynh_print_info --message="The service $service_name has correctly started."
                break
            fi
            if [ $i -eq 3 ]; then
                echo -n "Please wait, the service $service_name is ${action}ing" >&2
            fi
            if [ $i -ge 3 ]; then
                echo -n "." >&2
            fi
            sleep 1
        done
        if [ $i -ge 3 ]; then
            echo "" >&2
        fi
        if [ $i -eq $timeout ]
        then
            ynh_print_warn --message="The service $service_name didn't fully started before the timeout."
            ynh_print_warn --message="Please find here an extract of the end of the log of the service $service_name:"
            journalctl --no-pager --lines=$length -u $service_name >&2
            test -e "$log_path" && echo "--" >&2 && tail --lines=$length "$log_path" >&2
        fi
        ynh_clean_check_starting
    fi
}

# Clean temporary process and file used by ynh_check_starting
# (usually used in ynh_clean_setup scripts)
#
# usage: ynh_clean_check_starting
ynh_clean_check_starting () {
	# Stop the execution of tail.
	kill -s 15 $pid_tail 2>&1
	ynh_secure_remove "$templog" 2>&1
}

# Read the value of a key in a ynh manifest file
#
# usage: ynh_read_manifest manifest key
# | arg: -m, --manifest= - Path of the manifest to read
# | arg: -k, --key= - Name of the key to find
ynh_read_manifest () {
	# Declare an array to define the options of this helper.
        declare -Ar args_array=( [m]=manifest= [k]=manifest_key= )
        local manifest
        local manifest_key
	# Manage arguments with getopts
	ynh_handle_getopts_args "$@"

	if [ ! -e "$manifest" ]; then
		# If the manifest isn't found, try the common place for backup and restore script.
		manifest="../settings/manifest.json"
	fi

	jq ".$manifest_key" "$manifest" --raw-output
}

# Read the upstream version from the manifest
# The version number in the manifest is defined by <upstreamversion>~ynh<packageversion>
# For example : 4.3-2~ynh3
# This include the number before ~ynh
# In the last example it return 4.3-2
#
# usage: ynh_app_upstream_version [-m manifest]
# | arg: -m, --manifest= - Path of the manifest to read
ynh_app_upstream_version () {
    declare -Ar args_array=( [m]=manifest= )
    local manifest
    # Manage arguments with getopts
    ynh_handle_getopts_args "$@"

    manifest="${manifest:-../manifest.json}"
    version_key=$(ynh_read_manifest --manifest="$manifest" --manifest_key="version")
    echo "${version_key/~ynh*/}"
}

# Read package version from the manifest
# The version number in the manifest is defined by <upstreamversion>~ynh<packageversion>
# For example : 4.3-2~ynh3
# This include the number after ~ynh
# In the last example it return 3
#
# usage: ynh_app_package_version [-m manifest]
# | arg: -m, --manifest= - Path of the manifest to read
ynh_app_package_version () {
    declare -Ar args_array=( [m]=manifest= )
    local manifest
    # Manage arguments with getopts
    ynh_handle_getopts_args "$@"

    manifest="${manifest:-../manifest.json}"
    version_key=$(ynh_read_manifest --manifest="$manifest" --manifest_key="version")
    echo "${version_key/*~ynh/}"
}

# Checks the app version to upgrade with the existing app version and returns:
# - UPGRADE_APP if the upstream app version has changed
# - UPGRADE_PACKAGE if only the YunoHost package has changed
#
## It stops the current script without error if the package is up-to-date
#
# This helper should be used to avoid an upgrade of an app, or the upstream part
# of it, when it's not needed
#
# To force an upgrade, even if the package is up to date,
# you have to set the variable YNH_FORCE_UPGRADE before.
# example: sudo YNH_FORCE_UPGRADE=1 yunohost app upgrade MyApp
#
# usage: ynh_check_app_version_changed
ynh_check_app_version_changed () {
  local force_upgrade=${YNH_FORCE_UPGRADE:-0}
  local package_check=${PACKAGE_CHECK_EXEC:-0}

  # By default, upstream app version has changed
  local return_value="UPGRADE_APP"

  local current_version=$(ynh_read_manifest --manifest="/etc/yunohost/apps/$YNH_APP_INSTANCE_NAME/manifest.json" --manifest_key="version" || echo 1.0)
  local current_upstream_version="$(ynh_app_upstream_version --manifest="/etc/yunohost/apps/$YNH_APP_INSTANCE_NAME/manifest.json")"
  local update_version=$(ynh_read_manifest --manifest="../manifest.json" --manifest_key="version" || echo 1.0)
  local update_upstream_version="$(ynh_app_upstream_version)"

  if [ "$current_version" == "$update_version" ] ; then
      # Complete versions are the same
      if [ "$force_upgrade" != "0" ]
      then
        echo "Upgrade forced by YNH_FORCE_UPGRADE." >&2
        unset YNH_FORCE_UPGRADE
      elif [ "$package_check" != "0" ]
      then
        echo "Upgrade forced for package check." >&2
      else
        ynh_die "Up-to-date, nothing to do" 0
      fi
  elif [ "$current_upstream_version" == "$update_upstream_version" ] ; then
    # Upstream versions are the same, only YunoHost package versions differ
    return_value="UPGRADE_PACKAGE"
  fi
  echo $return_value
}