#!/bin/bash

PSQL_ROOT_PWD_FILE=/etc/yunohost/psql

# Open a connection as a user
#
# example: ynh_psql_connect_as 'user' 'pass' <<< "UPDATE ...;"
# example: ynh_psql_connect_as 'user' 'pass' < /path/to/file.sql
#
# usage: ynh_psql_connect_as --user=user --password=password [--database=database]
# | arg: -u, --user - the user name to connect as
# | arg: -p, --password - the user password
# | arg: -d, --database - the database to connect to
ynh_psql_connect_as() {
    # Declare an array to define the options of this helper.
    local legacy_args=upd
    declare -Ar args_array=( [u]=user= [p]=password= [d]=database= )
    local user
    local password
    local database
    # Manage arguments with getopts
    ynh_handle_getopts_args "$@"
    database="${database:-}"

	sudo --login --user=postgres PGUSER="$user" PGPASSWORD="$password" psql "$database"
}

# Execute a command as root user
#
# usage: ynh_psql_execute_as_root --sql=sql [--database=database]
# | arg: -s, --sql - the SQL command to execute
# | arg: -d, --database - the database to connect to
ynh_psql_execute_as_root () {
    # Declare an array to define the options of this helper.
    local legacy_args=sd
    declare -Ar args_array=( [s]=sql= [d]=database= )
    local sql
    local database
    # Manage arguments with getopts
    ynh_handle_getopts_args "$@"
    database="${database:-}"

    ynh_psql_connect_as --user="postgres" --password="$(sudo cat $PSQL_ROOT_PWD_FILE)" \
        --database="$database" <<< "$sql"
}

# Execute a command from a file as root user
#
# usage: ynh_psql_execute_file_as_root --file=file [--database=database]
# | arg: -f, --file - the file containing SQL commands
# | arg: -d, --database - the database to connect to
ynh_psql_execute_file_as_root() {
    # Declare an array to define the options of this helper.
    local legacy_args=fd
    declare -Ar args_array=( [f]=file= [d]=database= )
    local file
    local database
    # Manage arguments with getopts
    ynh_handle_getopts_args "$@"
    database="${database:-}"

    ynh_psql_connect_as --user="postgres" --password="$(sudo cat $PSQL_ROOT_PWD_FILE)" \
        --database="$database" < "$file"
}

# Create a database and grant optionnaly privilegies to a user
#
# [internal]
#
# usage: ynh_psql_create_db db [user [pwd]]
# | arg: db - the database name to create
# | arg: user - the user to grant privilegies
# | arg: pwd - the password to identify user by
ynh_psql_create_db() {
    local db=$1

    ynh_psql_create_user "$user" "$pwd"
	sudo --login --user=postgres createdb --owner="$user" "$db"
}

# Drop a database
#
# [internal]
#
# If you intend to drop the database *and* the associated user,
# consider using ynh_psql_remove_db instead.
#
# usage: ynh_psql_drop_db db
# | arg: db - the database name to drop
ynh_psql_drop_db() {
	local db=$1
    sudo --login --user=postgres dropdb $db
}

# Dump a database
#
# example: ynh_psql_dump_db 'roundcube' > ./dump.sql
#
# usage: ynh_psql_dump_db --database=database
# | arg: -d, --database - the database name to dump
# | ret: the psqldump output
ynh_psql_dump_db() {
    # Declare an array to define the options of this helper.
    local legacy_args=d
    declare -Ar args_array=( [d]=database= )
    local database
    # Manage arguments with getopts
    ynh_handle_getopts_args "$@"

    sudo --login --user=postgres pg_dump "$database"
}

# Create a user
#
# [internal]
#
# usage: ynh_psql_create_user user pwd [host]
# | arg: user - the user name to create
# | arg: pwd - the password to identify user by
ynh_psql_create_user() {
	local user=$1
	local psql=$2
	ynh_psql_execute_as_root --sql="CREATE USER $user WITH PASSWORD '$pwd'"
}

# Check if a psql user exists
#
# usage: ynh_psql_user_exists --user=user
# | arg: -u, --user - the user for which to check existence
ynh_psql_user_exists()
{
   # Declare an array to define the options of this helper.
   local legacy_args=u
   declare -Ar args_array=( [u]=user= )
   local user
   # Manage arguments with getopts
   ynh_handle_getopts_args "$@"

   if [[ -n $(sudo --login --user=postgres PGUSER="postgres" PGPASSWORD="$(sudo cat $PSQL_ROOT_PWD_FILE)" psql -tAc "SELECT rolname FROM pg_roles WHERE rolname='$user';") ]]
   then
      return 1
   else
      return 0
   fi
}

# Create a database, an user and its password. Then store the password in the app's config
#
# After executing this helper, the password of the created database will be available in $db_pwd
# It will also be stored as "psqlpwd" into the app settings.
#
# usage: ynh_psql_setup_db user name [pwd]
# | arg: user - Owner of the database
# | arg: name - Name of the database
# | arg: pwd - Password of the database. If not given, a password will be generated
ynh_psql_setup_db () {
	local db_user="$1"
	local db_name="$2"
	local new_db_pwd=$(ynh_string_random)	# Generate a random password
	# If $3 is not given, use new_db_pwd instead for db_pwd.
	local db_pwd="${3:-$new_db_pwd}"
	ynh_psql_create_db "$db_name" "$db_user" "$db_pwd"	# Create the database
	ynh_app_setting_set "$app" psqlpwd "$db_pwd"	# Store the password in the app's config
}

# Create a database and grant privilegies to a user
#
# usage: ynh_psql_create_db db [user [pwd]]
# | arg: db - the database name to create
# | arg: user - the user to grant privilegies
# | arg: pwd  - the user password
ynh_psql_create_db() {
	local db="$1"
	local user="$2"
	local pwd="$3"
	ynh_psql_create_user "$user" "$pwd"
	sudo --login --user=postgres createdb --owner="$user" "$db"
}

# Drop a database
#
# usage: ynh_psql_drop_db db
# | arg: db - the database name to drop
# | arg: user - the user to drop
ynh_psql_remove_db() {
	local db="$1"
	local user="$2"
	sudo --login --user=postgres dropdb "$db"
	ynh_psql_drop_user "$user"
}

# Dump a database
#
# example: ynh_psql_dump_db 'roundcube' > ./dump.sql
#
# usage: ynh_psql_dump_db db
# | arg: db - the database name to dump
# | ret: the psqldump output
ynh_psql_dump_db() {
	local db="$1"
	sudo --login --user=postgres pg_dump "$db"
}


# Create a user
#
# usage: ynh_psql_create_user user pwd [host]
# | arg: user - the user name to create
ynh_psql_create_user() {
	local user="$1"
	local pwd="$2"
	sudo --login --user=postgres psql -c"CREATE USER $user WITH PASSWORD '$pwd'" postgres
}

# Drop a user
#
# usage: ynh_psql_drop_user user
# | arg: user - the user name to drop
ynh_psql_drop_user() {
	local user="$1"
	sudo --login --user=postgres dropuser "$user"
}

# Create a master password and set up global settings
# Please always call this script in install and restore scripts
#
# usage: ynh_psql_test_if_first_run
ynh_psql_test_if_first_run() {
	if [ -f /etc/yunohost/psql ];
	then
		echo "PostgreSQL is already installed, no need to create master password"
	else
		local pgsql="$(ynh_string_random)"
		echo "$pgsql" > /etc/yunohost/psql

		if [ -e /etc/postgresql/9.4/ ]
		then
			local pg_hba=/etc/postgresql/9.4/main/pg_hba.conf
		elif [ -e /etc/postgresql/9.6/ ]
		then
			local pg_hba=/etc/postgresql/9.6/main/pg_hba.conf
		else
			ynh_die "postgresql shoud be 9.4 or 9.6"
		fi

		systemctl start postgresql
		sudo --login --user=postgres psql -c"ALTER user postgres WITH PASSWORD '$pgsql'" postgres

		# force all user to connect to local database using passwords
		# https://www.postgresql.org/docs/current/static/auth-pg-hba-conf.html#EXAMPLE-PG-HBA.CONF
		# Note: we can't use peer since YunoHost create users with nologin
		#  See: https://github.com/YunoHost/yunohost/blob/unstable/data/helpers.d/user
		sed -i '/local\s*all\s*all\s*peer/i \
			local all all password' "$pg_hba"
		systemctl enable postgresql
		systemctl reload postgresql
	fi
}