#!/usr/bin/env bash

## CREATES THE ENVIRONEMENT
export LANG=C
export LC_ALL=C

export PAAS_USER='hosting-user'
export APP_USER='hosting-app0'
export SYS_USER='hosting-admin'
export DB_USER='hosting-db'
export PHP_USER=${PAAS_USER}
export GITWEB_USER=${PAAS_USER}
export CUSTOMER_DIR='/srv/data'
export HOME="/home/${PAAS_USER}"
export LOCAL_DIR='/srv/run'
export PREFIX='/' # for npm

function do_as() {
    # TODO: Improve this by using SMACK
    local user="$1"
    shift

    /sbin/capsh --secbits=0x2f \
    --user="$user" --caps="all=" \
    -- -c 'exec "$0" "$@"' "$@"
    # Last line protects arguments separation
}

# Parses the arguments common to all init scripts, and sets
# the corresponding variables, but only applies them
# on start-lib.sh . It is the responsability of the calling
# script to set global effects (like changing the gateway).
# The reason for that is to respect modularity.
function parse_arguments() {
    while [ $# -gt 0 ]; do
    case "$1" in
        '--debug')
            export NO_TTY_REDIRECTIONS=true
            ;;
        '--rescue-grant-tables')
            export RESCUE_GRANT_TABLES=true
            ;;
        '--shell-start')
            export SHELL_START=true
            ;;
        '--')
            shift
            if [ $# -gt 1 ] && [ "$1" = "deploy" ]; then
                VHOST=$(extract_vhost "$2")
                export VHOST
                export TREEISH="$3"
            fi
            break
            ;;
    esac
    shift
    done
}

# Writes on its standard output the amount of available memory
# Requires /cgroup to be mounted
function get_cgroup_max_memory_mb() {
    # Parses the path to isolate the cgroup name
    local proc
    read -r proc < /proc/self/cgroup
    # Only keeps the last column
    local cgroup_name=${proc##*:}

    local mem_bytes
    read -r mem_bytes < "/cgroup/$cgroup_name/memory.limit_in_bytes"
    echo $(( mem_bytes / 1024 / 1024 ))
}

function logrotate_console_file() {
    local console_file="${CUSTOMER_DIR}/var/log/boot/console.log"
    local state_file=/dev/null
    local logrotate_conf="/srv/admin/configs/logrotate/console.conf"
    local logrotate_user=$SYS_USER

    # this is error prone due to bad usage of delegations by the kernel it may
    # fail if the console log file has been opened by eg. apache and then
    # instance is restarted
    set +e
    [ -f "$console_file" ] && chmod 646 "$console_file"
    do_as "$logrotate_user" /usr/sbin/logrotate -f -s "$state_file" \
        "$logrotate_conf" > /dev/null
    set -e
    return 0
}

function go_console() {
    if [[ -z "$NO_TTY_REDIRECTIONS" ]]; then
        logrotate_console_file
        exec < /dev/console
        exec &> /dev/console
    fi
}

function start_user_shell_on_tty() {
    local user="$1"
    local tty="$2"
    if [[ -z "$NO_TTY_REDIRECTIONS" ]]; then
        echo "Starting a shell for $user on $tty"
        /usr/local/bin/start-shell /usr/local/bin/restart-shell "$user" < "/dev/$tty" >& "/dev/$tty"
    fi
}

function extract_vhost() {
    local reponame="$1"

    reponame="${reponame#\'}"
    reponame="${reponame%\'}"
    echo "${reponame%.git}"
}

parse_json() {
    JSON_FILE=$1

    WWW_ENGINE=$(jq -er .language.name "${JSON_FILE}")
    WWW_VERSION=$(jq -er .language.version "${JSON_FILE}")
    DB_ENGINE=$(jq -er .database.name "${JSON_FILE}")
    DB_VERSION=$(jq -er .database.version "${JSON_FILE}")

    DB_PATH=$DB_ENGINE
    case "${DB_ENGINE}" in
        pgsql) DB_PATH="postgresql" ;;
    esac

    PATH="/usr/sbin:/usr/bin:/sbin/:/bin"
    for path in "bin" "sbin" "usr/bin" "usr/sbin"
    do
        PATH="$PATH:/opt/${WWW_ENGINE}-${WWW_VERSION}/${path}"
        PATH="$PATH:/opt/${DB_PATH}-${DB_VERSION}/${path}"
    done

    case "${DB_ENGINE}" in
        mysql)
            lib_path="/opt/mysql-${DB_VERSION}/lib/x86_64-linux-gnu" ;;
        pgsql)
            lib_path="/opt/postgresql-${DB_VERSION}/lib" ;;
    esac
    if [ -n "${lib_path-}" ]; then
        if [ -n "${LD_LIBRARY_PATH-}" ]; then
            LD_LIBRARY_PATH="${LD_LIBRARY_PATH}:${lib_path}"
        else
            LD_LIBRARY_PATH="${lib_path}"
        fi
    fi

    export PATH
    export WWW_ENGINE
    export WWW_VERSION
    export DB_ENGINE
    export DB_VERSION
    export LD_LIBRARY_PATH
}