#!/bin/bash
#
# Apache v2 license
# Copyright (C) 2023 Intel Corporation
# SPDX-License-Identifier: Apache-2.0
#
set -eo pipefail
shopt -s nullglob

# logging functions
mysql_log() {
        local type="$1"; shift
        # accept argument string or stdin
        local text="$*"; if [ "$#" -eq 0 ]; then text="$(cat)"; fi
        local dt; dt="$(date --rfc-3339=seconds)"
        printf '%s [%s] [Entrypoint]: %s\n' "$dt" "$type" "$text"
}
mysql_note() {
        mysql_log Note "$@"
}
mysql_warn() {
        mysql_log Warn "$@" >&2
}
mysql_error() {
        mysql_log ERROR "$@" >&2
        exit 1
}

# usage: file_env VAR [DEFAULT]
#    ie: file_env 'XYZ_DB_PASSWORD' 'example'
# (will allow for "$XYZ_DB_PASSWORD_FILE" to fill in the value of
#  "$XYZ_DB_PASSWORD" from a file, especially for Docker's secrets feature)
file_env() {
        local var="$1"
        local fileVar="${var}_FILE"
        local def="${2:-}"
        if [ "${!var:-}" ] && [ "${!fileVar:-}" ]; then
                mysql_error "Both $var and $fileVar are set (but are exclusive)"
        fi
        local val="$def"
        if [ "${!var:-}" ]; then
                val="${!var}"
        elif [ "${!fileVar:-}" ]; then
                val="$(< "${!fileVar}")"
        fi
        export "$var"="$val"
        unset "$fileVar"
}

# check to see if this file is being run or sourced from another script
_is_sourced() {
        # https://unix.stackexchange.com/a/215279
        [ "${#FUNCNAME[@]}" -ge 2 ] \
                && [ "${FUNCNAME[0]}" = '_is_sourced' ] \
                && [ "${FUNCNAME[1]}" = 'source' ]
}

# usage: docker_process_init_files [file [file [...]]]
#    ie: docker_process_init_files /always-initdb.d/*
# process initializer files, based on file extensions
docker_process_init_files() {
        # mysql here for backwards compatibility "${mysql[@]}"
        mysql=( docker_process_sql )

        echo
        local f
        for f; do
                case "$f" in
                        *.sh)
                                # https://github.com/docker-library/postgres/issues/450#issuecomment-393167936
                                # https://github.com/docker-library/postgres/pull/452
                                if [ -x "$f" ]; then
                                        mysql_note "$0: running $f"
                                        "$f"
                                else
                                        mysql_note "$0: sourcing $f"
                                        . "$f"
                                fi
                                ;;
                        *.sql)     mysql_note "$0: running $f"; docker_process_sql < "$f"; echo ;;
                        *.sql.bz2) mysql_note "$0: running $f"; bunzip2 -c "$f" | docker_process_sql; echo ;;
                        *.sql.gz)  mysql_note "$0: running $f"; gunzip -c "$f" | docker_process_sql; echo ;;
                        *.sql.xz)  mysql_note "$0: running $f"; xzcat "$f" | docker_process_sql; echo ;;
                        *.sql.zst) mysql_note "$0: running $f"; zstd -dc "$f" | docker_process_sql; echo ;;
                        *)         mysql_warn "$0: ignoring $f" ;;
                esac
                echo
        done
}

# arguments necessary to run "mysqld --verbose --help" successfully (used for testing configuration validity and for extracting default/configured values)
_verboseHelpArgs=(
        --verbose --help
        --log-bin-index="$(mktemp -u)" # https://github.com/docker-library/mysql/issues/136
)

mysql_check_config() {
        local toRun=( "$@" "${_verboseHelpArgs[@]}" ) errors
        if ! errors="$("${toRun[@]}" 2>&1 >/dev/null)"; then
                mysql_error $'mysqld failed while attempting to check config\n\tcommand was: '"${toRun[*]}"$'\n\t'"$errors"
        fi
}

# Fetch value from server config
# We use mysqld --verbose --help instead of my_print_defaults because the
# latter only show values present in config files, and not server defaults
mysql_get_config() {
        local conf="$1"; shift
        "$@" "${_verboseHelpArgs[@]}" 2>/dev/null \
                | awk -v conf="$conf" '$1 == conf && /^[^ \t]/ { sub(/^[^ \t]+[ \t]+/, ""); print; exit }'
        # match "datadir      /some/path with/spaces in/it here" but not "--xyz=abc\n     datadir (xyz)"
}

# Ensure that the package default socket can also be used
# since rpm packages are compiled with a different socket location
# and "mysqlsh --mysql" doesn't read the [client] config
# related to https://github.com/docker-library/mysql/issues/829
mysql_socket_fix() {
        local defaultSocket
        defaultSocket="$(mysql_get_config 'socket' mysqld --no-defaults)"
        if [ "$defaultSocket" != "$SOCKET" ]; then
                ln -sfTv "$SOCKET" "$defaultSocket" || :
        fi
}

# Do a temporary startup of the MySQL server, for init purposes
docker_temp_server_start() {
        if [ "${MYSQL_MAJOR}" = '5.7' ]; then
                "$@" --skip-networking --default-time-zone=SYSTEM --socket="${SOCKET}" &
                mysql_note "Waiting for server startup"
                local i
                for i in {30..0}; do
                        # only use the root password if the database has already been initialized
                        # so that it won't try to fill in a password file when it hasn't been set yet
                        extraArgs=()
                        if [ -z "$DATABASE_ALREADY_EXISTS" ]; then
                                extraArgs+=( '--dont-use-mysql-root-password' )
                        fi
                        if docker_process_sql "${extraArgs[@]}" --database=mysql <<<'SELECT 1' &> /dev/null; then
                                break
                        fi
                        sleep 1
                done
                if [ "$i" = 0 ]; then
                        mysql_error "Unable to start server."
                fi
        else
                # For 5.7+ the server is ready for use as soon as startup command unblocks
                if ! "$@" --daemonize --skip-networking --default-time-zone=SYSTEM --socket="${SOCKET}"; then
                        mysql_error "Unable to start server."
                fi
        fi
}

# Stop the server. When using a local socket file mysqladmin will block until
# the shutdown is complete.
docker_temp_server_stop() {
        if ! mysqladmin --defaults-extra-file=<( _mysql_passfile ) shutdown -uroot --socket="${SOCKET}"; then
                mysql_error "Unable to shut down server."
        fi
}

# Verify that the minimally required password settings are set for new databases.
docker_verify_minimum_env() {
        if [ -z "$MYSQL_ROOT_PASSWORD" -a -z "$MYSQL_ALLOW_EMPTY_PASSWORD" -a -z "$MYSQL_RANDOM_ROOT_PASSWORD" ]; then
                mysql_error <<-'EOF'
                        Database is uninitialized and password option is not specified
                            You need to specify one of the following as an environment variable:
                            - MYSQL_ROOT_PASSWORD
                            - MYSQL_ALLOW_EMPTY_PASSWORD
                            - MYSQL_RANDOM_ROOT_PASSWORD
EOF
        fi

        # This will prevent the CREATE USER from failing (and thus exiting with a half-initialized database)
        if [ "$MYSQL_USER" = 'root' ]; then
                mysql_error <<-'EOF'
                        MYSQL_USER="root", MYSQL_USER and MYSQL_PASSWORD are for configuring a regular user and cannot be used for the root user
                            Remove MYSQL_USER="root" and use one of the following to control the root user password:
                            - MYSQL_ROOT_PASSWORD
                            - MYSQL_ALLOW_EMPTY_PASSWORD
                            - MYSQL_RANDOM_ROOT_PASSWORD
EOF
        fi

        # warn when missing one of MYSQL_USER or MYSQL_PASSWORD
        if [ -n "$MYSQL_USER" ] && [ -z "$MYSQL_PASSWORD" ]; then
                mysql_warn 'MYSQL_USER specified, but missing MYSQL_PASSWORD; MYSQL_USER will not be created'
        elif [ -z "$MYSQL_USER" ] && [ -n "$MYSQL_PASSWORD" ]; then
                mysql_warn 'MYSQL_PASSWORD specified, but missing MYSQL_USER; MYSQL_PASSWORD will be ignored'
        fi
}

# creates folders for the database
# also ensures permission for user mysql of run as root
docker_create_db_directories() {
        local user; user="$(id -u)"

        local -A dirs=( ["$DATADIR"]=1 )
        local dir
        dir="$(dirname "$SOCKET")"
        dirs["$dir"]=1

        # "datadir" and "socket" are already handled above (since they were already queried previously)
        local conf
        for conf in \
                general-log-file \
                keyring_file_data \
                pid-file \
                secure-file-priv \
                slow-query-log-file \
        ; do
                dir="$(mysql_get_config "$conf" "$@")"

                # skip empty values
                if [ -z "$dir" ] || [ "$dir" = 'NULL' ]; then
                        continue
                fi
                case "$conf" in
                        secure-file-priv)
                                # already points at a directory
                                ;;
                        *)
                                # other config options point at a file, but we need the directory
                                dir="$(dirname "$dir")"
                                ;;
                esac

                dirs["$dir"]=1
        done

        mkdir -p "${!dirs[@]}"

        if [ "$user" = "0" ]; then
                # this will cause less disk access than `chown -R`
                find "${!dirs[@]}" \! -user mysql -exec chown --no-dereference mysql '{}' +
        fi
}

# initializes the database directory
docker_init_database_dir() {
        mysql_note "Initializing database files"
        "$@" --initialize-insecure --default-time-zone=SYSTEM
        mysql_note "Database files initialized"
}

# Loads various settings that are used elsewhere in the script
# This should be called after mysql_check_config, but before any other functions
docker_setup_env() {
        # Get config
        declare -g DATADIR SOCKET
        DATADIR="$(mysql_get_config 'datadir' "$@")"
        SOCKET="$(mysql_get_config 'socket' "$@")"

        # Initialize values that might be stored in a file
        file_env 'MYSQL_ROOT_HOST' '%'
        file_env 'MYSQL_DATABASE'
        file_env 'MYSQL_USER'
        file_env 'MYSQL_PASSWORD'
        file_env 'MYSQL_ROOT_PASSWORD'

        declare -g DATABASE_ALREADY_EXISTS
        if [ -d "$DATADIR/mysql" ]; then
                DATABASE_ALREADY_EXISTS='true'
        fi
}

# Execute sql script, passed via stdin
# usage: docker_process_sql [--dont-use-mysql-root-password] [mysql-cli-args]
#    ie: docker_process_sql --database=mydb <<<'INSERT ...'
#    ie: docker_process_sql --dont-use-mysql-root-password --database=mydb <my-file.sql
docker_process_sql() {
        passfileArgs=()
        if [ '--dont-use-mysql-root-password' = "$1" ]; then
                passfileArgs+=( "$1" )
                shift
        fi
        # args sent in can override this db, since they will be later in the command
        if [ -n "$MYSQL_DATABASE" ]; then
                set -- --database="$MYSQL_DATABASE" "$@"
        fi

        mysql --defaults-extra-file=<( _mysql_passfile "${passfileArgs[@]}") --protocol=socket -uroot -hlocalhost --socket="${SOCKET}" --comments "$@"
}

# Initializes database with timezone info and root password, plus optional extra db/user
docker_setup_db() {
        # Load timezone info into database
        if [ -z "$MYSQL_INITDB_SKIP_TZINFO" ]; then
                # sed is for https://bugs.mysql.com/bug.php?id=20545
                mysql_tzinfo_to_sql /usr/share/zoneinfo \
                        | sed 's/Local time zone must be set--see zic manual page/FCTY/' \
                        | docker_process_sql --dont-use-mysql-root-password --database=mysql
                        # tell docker_process_sql to not use MYSQL_ROOT_PASSWORD since it is not set yet
        fi
        # Generate random root password
        if [ -n "$MYSQL_RANDOM_ROOT_PASSWORD" ]; then
                MYSQL_ROOT_PASSWORD="$(openssl rand -base64 24)"; export MYSQL_ROOT_PASSWORD
                mysql_note "GENERATED ROOT PASSWORD: $MYSQL_ROOT_PASSWORD"
        fi
        # Sets root password and creates root users for non-localhost hosts
        local rootCreate=
        # default root to listen for connections from anywhere
        if [ -n "$MYSQL_ROOT_HOST" ] && [ "$MYSQL_ROOT_HOST" != 'localhost' ]; then
                # no, we don't care if read finds a terminating character in this heredoc
                # https://unix.stackexchange.com/questions/265149/why-is-set-o-errexit-breaking-this-read-heredoc-expression/265151#265151
                read -r -d '' rootCreate <<-EOSQL || true
                        CREATE USER 'root'@'${MYSQL_ROOT_HOST}' IDENTIFIED BY '${MYSQL_ROOT_PASSWORD}' ;
                        GRANT ALL ON *.* TO 'root'@'${MYSQL_ROOT_HOST}' WITH GRANT OPTION ;
EOSQL
        fi

        local passwordSet=
        # no, we don't care if read finds a terminating character in this heredoc (see above)
        read -r -d '' passwordSet <<-EOSQL || true
                ALTER USER 'root'@'localhost' IDENTIFIED BY '${MYSQL_ROOT_PASSWORD}' ;
EOSQL

        # tell docker_process_sql to not use MYSQL_ROOT_PASSWORD since it is just now being set
        docker_process_sql --dont-use-mysql-root-password --database=mysql <<-EOSQL
                -- What's done in this file shouldn't be replicated
                --  or products like mysql-fabric won't work
                SET @@SESSION.SQL_LOG_BIN=0;
                ${passwordSet}
                GRANT ALL ON *.* TO 'root'@'localhost' WITH GRANT OPTION ;
                FLUSH PRIVILEGES ;
                ${rootCreate}
                DROP DATABASE IF EXISTS test ;
EOSQL

        # Creates a custom database and user if specified
        if [ -n "$MYSQL_DATABASE" ]; then
                mysql_note "Creating database ${MYSQL_DATABASE}"
                docker_process_sql --database=mysql <<<"CREATE DATABASE IF NOT EXISTS \`$MYSQL_DATABASE\` ;"
        fi

        if [ -n "$MYSQL_USER" ] && [ -n "$MYSQL_PASSWORD" ]; then
                mysql_note "Creating user ${MYSQL_USER}"
                docker_process_sql --database=mysql <<<"CREATE USER '$MYSQL_USER'@'%' IDENTIFIED BY '$MYSQL_PASSWORD' ;"

                if [ -n "$MYSQL_DATABASE" ]; then
                        mysql_note "Giving user ${MYSQL_USER} access to schema ${MYSQL_DATABASE}"
                        docker_process_sql --database=mysql <<<"GRANT ALL ON \`${MYSQL_DATABASE//_/\\_}\`.* TO '$MYSQL_USER'@'%' ;"
                fi
        fi
}

_mysql_passfile() {
        # echo the password to the "file" the client uses
        # the client command will use process substitution to create a file on the fly
        # ie: --defaults-extra-file=<( _mysql_passfile )
        if [ '--dont-use-mysql-root-password' != "$1" ] && [ -n "$MYSQL_ROOT_PASSWORD" ]; then
                cat <<-EOF
                        [client]
                        password="${MYSQL_ROOT_PASSWORD}"
EOF
        fi
}

# Mark root user as expired so the password must be changed before anything
# else can be done (only supported for 5.6+)
mysql_expire_root_user() {
        if [ -n "$MYSQL_ONETIME_PASSWORD" ]; then
                docker_process_sql --database=mysql <<-EOSQL
                        ALTER USER 'root'@'%' PASSWORD EXPIRE;
EOSQL
        fi
}

# check arguments for an option that would cause mysqld to stop
# return true if there is one
_mysql_want_help() {
        local arg
        for arg; do
                case "$arg" in
                        -'?'|--help|--print-defaults|-V|--version)
                                return 0
                                ;;
                esac
        done
        return 1
}

_main() {
        # if command starts with an option, prepend mysqld
        if [ "${1:0:1}" = '-' ]; then
                set -- mysqld "$@"
        fi

        # skip setup if they aren't running mysqld or want an option that stops mysqld
        if [ "$1" = 'mysqld' ] && ! _mysql_want_help "$@"; then
                mysql_note "Entrypoint script for MySQL Server ${MYSQL_VERSION} started."

                mysql_check_config "$@"
                # Load various environment variables
                docker_setup_env "$@"
                docker_create_db_directories "$@"

                # If container is started as root user, restart as dedicated mysql user
                if [ "$(id -u)" = "0" ]; then
                        mysql_note "Switching to dedicated user 'mysql'"
                        exec gosu mysql "$BASH_SOURCE" "$@"
                fi

                # there's no database, so it needs to be initialized
                if [ -z "$DATABASE_ALREADY_EXISTS" ]; then
                        docker_verify_minimum_env

                        # check dir permissions to reduce likelihood of half-initialized database
                        ls /docker-entrypoint-initdb.d/ > /dev/null

                        docker_init_database_dir "$@"

                        mysql_note "Starting temporary server"
                        docker_temp_server_start "$@"
                        mysql_note "Temporary server started."

                        mysql_socket_fix
                        docker_setup_db
                        docker_process_init_files /docker-entrypoint-initdb.d/*

                        mysql_expire_root_user

                        mysql_note "Stopping temporary server"
                        docker_temp_server_stop
                        mysql_note "Temporary server stopped"

                        echo
                        mysql_note "MySQL init process done. Ready for start up."
                        echo
                else
                        mysql_socket_fix
                fi
        fi
        exec "$@"
}

# If we are sourced from elsewhere, don't perform any further actions
if ! _is_sourced; then
        _main "$@"
fi