#!/bin/bash

CHECK_VAR () {	# Verifies that the variable is not empty.
	# $1 = Variable to be checked
	# $2 = Display text on error
	test -n "$1" || (echo "$2" >&2 && false)
}


# 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 : $app
# | arg: -a, --action=       - Action to perform with systemctl. Default: start
# | arg: -l, --line_match=   - Line to match - The line to find in the log to attest the service have finished to boot.
#                              If not defined it don't wait until the service is completely started.
# | arg: -p, --log_path=     - Log file - Path to the log file. Default : /var/log/$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 -u $service_name -f --since=-45 > "$templog" &
	else
            # Read the specified log file
            tail -F -n0 "$log_path" > "$templog" &
	fi
        # Get the PID of the tail command
        local pid_tail=$!
    fi

    echo "${action^} the service $service_name" >&2
    systemctl $action $service_name \
        || ( journalctl --lines=$length -u $service_name >&2 \
        ; test -n "$log_path" && echo "--" && 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
                echo "The service $service_name has correctly started." >&2
                break
            fi
            echo -n "." >&2
            sleep 1
        done
        if [ $i -eq $timeout ]
        then
            echo "The service $service_name didn't fully started before the timeout." >&2
            echo "Please find here an extract of the end of the log of the service $service_name:"
            journalctl --lines=$length -u $service_name >&2
            test -n "$log_path" && echo "--" && tail --lines=$length "$log_path" >&2
        fi

        echo ""
        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
}

#=================================================
# EXPERIMENTAL HELPERS
#=================================================

# Send an email to inform the administrator
#
# usage: ynh_send_readme_to_admin --app_message=app_message [--recipients=recipients] [--type=type]
# | arg: -m --app_message= - The file with the content to send to the administrator.
# | arg: -r, --recipients= - The recipients of this email. Use spaces to separate multiples recipients. - default: root
#	example: "root admin@domain"
#	If you give the name of a YunoHost user, ynh_send_readme_to_admin will find its email adress for you
#	example: "root admin@domain user1 user2"
# | arg: -t, --type= - Type of mail, could be 'backup', 'change_url', 'install', 'remove', 'restore', 'upgrade'
ynh_send_readme_to_admin() {
	# Declare an array to define the options of this helper.
	declare -Ar args_array=( [m]=app_message= [r]=recipients= [t]=type= )
	local app_message
	local recipients
	local type
	# Manage arguments with getopts

	ynh_handle_getopts_args "$@"
	app_message="${app_message:-}"
	recipients="${recipients:-root}"
	type="${type:-install}"

	# Get the value of admin_mail_html
	admin_mail_html=$(ynh_app_setting_get $app admin_mail_html)
	admin_mail_html="${admin_mail_html:-0}"

	# Retrieve the email of users
	find_mails () {
		local list_mails="$1"
		local mail
		local recipients=" "
		# Read each mail in argument
		for mail in $list_mails
		do
			# Keep root or a real email address as it is
			if [ "$mail" = "root" ] || echo "$mail" | grep --quiet "@"
			then
				recipients="$recipients $mail"
			else
				# But replace an user name without a domain after by its email
				if mail=$(ynh_user_get_info "$mail" "mail" 2> /dev/null)
				then
					recipients="$recipients $mail"
				fi
			fi
		done
		echo "$recipients"
	}
	recipients=$(find_mails "$recipients")

	# Subject base
	local mail_subject="☁️🆈🅽🅷☁️: \`$app\`"

	# Adapt the subject according to the type of mail required.
	if [ "$type" = "backup" ]; then
		mail_subject="$mail_subject has just been backup."
	elif [ "$type" = "change_url" ]; then
		mail_subject="$mail_subject has just been moved to a new URL!"
	elif [ "$type" = "remove" ]; then
		mail_subject="$mail_subject has just been removed!"
	elif [ "$type" = "restore" ]; then
		mail_subject="$mail_subject has just been restored!"
	elif [ "$type" = "upgrade" ]; then
		mail_subject="$mail_subject has just been upgraded!"
	else	# install
		mail_subject="$mail_subject has just been installed!"
	fi

	local mail_message="This is an automated message from your beloved YunoHost server.
Specific information for the application $app.
$(if [ -n "$app_message" ]
then
	cat "$app_message"
else
	echo "...No specific information..."
fi)
---
Automatic diagnosis data from YunoHost
__PRE_TAG1__$(yunohost tools diagnosis | grep -B 100 "services:" | sed '/services:/d')__PRE_TAG2__"

	# Store the message into a file for further modifications.
	echo "$mail_message" > mail_to_send

	# If a html email is required. Apply html tags to the message.
 	if [ "$admin_mail_html" -eq 1 ]
 	then
		# Insert 'br' tags at each ending of lines.
		ynh_replace_string "$" "<br>" mail_to_send

		# Insert starting HTML tags
		sed --in-place '1s@^@<!DOCTYPE html>\n<html>\n<head></head>\n<body>\n@' mail_to_send

		# Keep tabulations
		ynh_replace_string "  " "\&#160;\&#160;" mail_to_send
		ynh_replace_string "\t" "\&#160;\&#160;" mail_to_send

		# Insert url links tags
		ynh_replace_string "__URL_TAG1__\(.*\)__URL_TAG2__\(.*\)__URL_TAG3__" "<a href=\"\2\">\1</a>" mail_to_send

		# Insert pre tags
		ynh_replace_string "__PRE_TAG1__" "<pre>" mail_to_send
		ynh_replace_string "__PRE_TAG2__" "<\pre>" mail_to_send

		# Insert finishing HTML tags
		echo -e "\n</body>\n</html>" >> mail_to_send

	# Otherwise, remove tags to keep a plain text.
	else
		# Remove URL tags
		ynh_replace_string "__URL_TAG[1,3]__" "" mail_to_send
		ynh_replace_string "__URL_TAG2__" ": " mail_to_send

		# Remove PRE tags
		ynh_replace_string "__PRE_TAG[1-2]__" "" mail_to_send
	fi

	# Define binary to use for mail command
	if [ -e /usr/bin/bsd-mailx ]
	then
		local mail_bin=/usr/bin/bsd-mailx
	else
		local mail_bin=/usr/bin/mail.mailutils
	fi

	if [ "$admin_mail_html" -eq 1 ]
	then
		content_type="text/html"
	else
		content_type="text/plain"
	fi

	# Send the email to the recipients
	cat mail_to_send | $mail_bin -a "Content-Type: $content_type; charset=UTF-8" -s "$mail_subject" "$recipients"
}