# Shared support for MongoDB sharded-cluster scripts.
# This file is sourced and should not itself be executed.

. ./_mongodb_script_common.bash

gs_mongodb_require_mode cluster

gs_mongodb_require_command mongod
gs_mongodb_require_command mongos
gs_mongodb_require_command "$GS_MONGODB_SHELL"

: "${GS_MONGODB_ROUTER_HOSTNAME:?Missing GS_MONGODB_ROUTER_HOSTNAME}"
: "${GS_MONGODB_ROUTER_PORT:?Missing GS_MONGODB_ROUTER_PORT}"
: "${GS_MONGODB_CONFIG_SERVER_HOSTNAME:?Missing GS_MONGODB_CONFIG_SERVER_HOSTNAME}"
: "${GS_MONGODB_CONFIG_SERVER_PORT:?Missing GS_MONGODB_CONFIG_SERVER_PORT}"
: "${GS_MONGODB_CONFIG_REPLSET:?Missing GS_MONGODB_CONFIG_REPLSET}"
: "${GS_MONGODB_SHARD_PORT:?Missing GS_MONGODB_SHARD_PORT}"
: "${GS_MONGODB_SHARD_REPLSET_PREFIX:?Missing GS_MONGODB_SHARD_REPLSET_PREFIX}"
: "${GS_MONGODB_CLUSTER_HOME:?Missing GS_MONGODB_CLUSTER_HOME}"
: "${GS_MONGODB_REMOTE_SOURCE_DIR:?Missing GS_MONGODB_REMOTE_SOURCE_DIR}"

GS_MONGODB_START_TIMEOUT="${GS_MONGODB_START_TIMEOUT:-60}"
GS_MONGODB_PRIMARY_TIMEOUT="${GS_MONGODB_PRIMARY_TIMEOUT:-60}"
GS_MONGODB_CLUSTER_LOOPBACK_ADDRESS="${GS_MONGODB_CLUSTER_LOOPBACK_ADDRESS:-127.0.0.1}"
GS_MONGODB_SSH_COMMAND="${GS_MONGODB_SSH_COMMAND:-ssh}"
GS_MONGODB_SCP_COMMAND="${GS_MONGODB_SCP_COMMAND:-scp}"

gs_mongodb_cluster_validate_port()
{
    name=$1
    port=$2
    case "$port" in
        ''|*[!0-9]*) gs_mongodb_die "$name is not a numeric port: $port" ;;
    esac
    [ "$port" -ge 1 ] && [ "$port" -le 65535 ] ||
        gs_mongodb_die "$name is outside the range 1-65535: $port"
}

gs_mongodb_cluster_short_hostname()
{
    echo "${1%%.*}"
}

gs_mongodb_cluster_host_is_local()
{
    configured_host=$1
    configured_short=$(gs_mongodb_cluster_short_hostname "$configured_host")
    local_short=$(hostname -s 2>/dev/null || hostname)
    local_full=$(hostname -f 2>/dev/null || hostname)

    [ "$configured_host" = "$local_short" ] && return 0
    [ "$configured_host" = "$local_full" ] && return 0
    [ "$configured_short" = "$local_short" ] && return 0

    # Also recognise a configured DNS alias that resolves to a local address.
    if command -v getent >/dev/null 2>&1; then
        configured_addresses=$(getent ahostsv4 "$configured_host" 2>/dev/null | awk '{print $1}' | sort -u)
        local_addresses="$(hostname -I 2>/dev/null || true)
$(getent ahostsv4 "$local_short" 2>/dev/null | awk '{print $1}' || true)
$(getent ahostsv4 "$local_full" 2>/dev/null | awk '{print $1}' || true)"

        for configured_address in $configured_addresses; do
            for local_address in $local_addresses; do
                [ "$configured_address" = "$local_address" ] && return 0
            done
        done
    fi

    return 1
}

gs_mongodb_cluster_shard_replset()
{
    shard_index=$1
    echo "${GS_MONGODB_SHARD_REPLSET_PREFIX}$((shard_index + 1))"
}

gs_mongodb_cluster_shard_host()
{
    shard_index=$1
    echo "${GS_MONGODB_SHARD_HOSTNAMES[$shard_index]}"
}

gs_mongodb_cluster_shard_connection()
{
    shard_index=$1
    shard_host=$(gs_mongodb_cluster_shard_host "$shard_index")
    shard_replset=$(gs_mongodb_cluster_shard_replset "$shard_index")
    echo "${shard_replset}/${shard_host}:${GS_MONGODB_SHARD_PORT}"
}

gs_mongodb_cluster_find_local_shard()
{
    found_index=-1
    for shard_index in "${!GS_MONGODB_SHARD_HOSTNAMES[@]}"; do
        if gs_mongodb_cluster_host_is_local "${GS_MONGODB_SHARD_HOSTNAMES[$shard_index]}"; then
            if [ "$found_index" -ne -1 ]; then
                gs_mongodb_die "The local machine appears more than once in GS_MONGODB_SHARD_HOSTNAMES."
            fi
            found_index=$shard_index
        fi
    done

    [ "$found_index" -ne -1 ] || return 1
    echo "$found_index"
}

gs_mongodb_cluster_require_local_role()
{
    role=$1
    host=$2
    if ! gs_mongodb_cluster_host_is_local "$host"; then
        gs_mongodb_die "This script is for the $role host '$host'; the current host is '$(hostname -s)'."
    fi
}

gs_mongodb_cluster_configdb()
{
    echo "${GS_MONGODB_CONFIG_REPLSET}/${GS_MONGODB_CONFIG_SERVER_HOSTNAME}:${GS_MONGODB_CONFIG_SERVER_PORT}"
}

gs_mongodb_cluster_prepare_common_dirs()
{
    mkdir -p \
        "$GS_MONGODB_CLUSTER_HOME/config-server/data" \
        "$GS_MONGODB_CLUSTER_HOME/config-server/log" \
        "$GS_MONGODB_CLUSTER_HOME/config-server/run" \
        "$GS_MONGODB_CLUSTER_HOME/router/log" \
        "$GS_MONGODB_CLUSTER_HOME/router/run"
}

gs_mongodb_cluster_prepare_shard_dirs()
{
    shard_index=$1
    shard_number=$((shard_index + 1))
    mkdir -p \
        "$GS_MONGODB_CLUSTER_HOME/shards/shard-${shard_number}/data" \
        "$GS_MONGODB_CLUSTER_HOME/shards/shard-${shard_number}/log" \
        "$GS_MONGODB_CLUSTER_HOME/shards/shard-${shard_number}/run"
}

gs_mongodb_cluster_shell_eval()
{
    host=$1
    port=$2
    javascript=$3

    "$GS_MONGODB_SHELL" \
        --quiet \
        --host "$host" \
        --port "$port" \
        --eval "$javascript"
}

gs_mongodb_cluster_wait_for_ping()
{
    description=$1
    host=$2
    port=$3
    timeout=${4:-60}

    echo "Waiting for $description at $host:$port ..."
    elapsed=0
    while [ "$elapsed" -lt "$timeout" ]; do
        if gs_mongodb_cluster_shell_eval \
            "$host" "$port" \
            'quit(db.getSiblingDB("admin").runCommand({ping:1}).ok === 1 ? 0 : 1)' \
            >/dev/null 2>&1
        then
            echo "$description is accepting connections."
            return 0
        fi
        sleep 1
        elapsed=$((elapsed + 1))
    done

    echo "Timed out waiting for $description at $host:$port." >&2
    return 1
}

gs_mongodb_cluster_wait_for_primary()
{
    description=$1
    host=$2
    port=$3
    timeout=${4:-60}

    echo "Waiting for $description to become PRIMARY ..."
    elapsed=0
    while [ "$elapsed" -lt "$timeout" ]; do
        if gs_mongodb_cluster_shell_eval \
            "$host" "$port" \
            'var s=db.getSiblingDB("admin").runCommand({isMaster:1}); quit(s.ismaster ? 0 : 1)' \
            >/dev/null 2>&1
        then
            echo "$description is PRIMARY."
            return 0
        fi
        sleep 1
        elapsed=$((elapsed + 1))
    done

    echo "Timed out waiting for $description to become PRIMARY." >&2
    return 1
}

gs_mongodb_cluster_remote_run()
{
    host=$1
    script_name=$2
    shift 2

    if gs_mongodb_cluster_host_is_local "$host"; then
        (cd "$GS_MONGODB_SOURCE_HOME" && "./CLUSTER-SERVER/$script_name" "$@")
        return
    fi

    printf -v remote_dir_q '%q' "$GS_MONGODB_REMOTE_SOURCE_DIR"
    remote_command="cd $remote_dir_q && ./CLUSTER-SERVER/$script_name"
    for argument in "$@"; do
        printf -v argument_q '%q' "$argument"
        remote_command="$remote_command $argument_q"
    done

    "$GS_MONGODB_SSH_COMMAND" \
        "${GS_MONGODB_SSH_OPTIONS[@]}" \
        "$host" \
        "$remote_command"
}

gs_mongodb_cluster_validate_configuration()
{
    case "$GS_MONGODB_ROUTER_HOSTNAME $GS_MONGODB_CONFIG_SERVER_HOSTNAME ${GS_MONGODB_SHARD_HOSTNAMES[*]}" in
        *hostname-mongo-*)
            gs_mongodb_die "The cluster setup still contains hostname-mongo-* template values."
            ;;
    esac

    [ "${#GS_MONGODB_SHARD_HOSTNAMES[@]}" -gt 0 ] ||
        gs_mongodb_die "GS_MONGODB_SHARD_HOSTNAMES must contain at least one hostname."

    gs_mongodb_cluster_validate_port GS_MONGODB_ROUTER_PORT "$GS_MONGODB_ROUTER_PORT"
    gs_mongodb_cluster_validate_port GS_MONGODB_CONFIG_SERVER_PORT "$GS_MONGODB_CONFIG_SERVER_PORT"
    gs_mongodb_cluster_validate_port GS_MONGODB_SHARD_PORT "$GS_MONGODB_SHARD_PORT"

    for first_index in "${!GS_MONGODB_SHARD_HOSTNAMES[@]}"; do
        first_host=${GS_MONGODB_SHARD_HOSTNAMES[$first_index]}
        [ -n "$first_host" ] || gs_mongodb_die "Shard hostname $((first_index + 1)) is empty."

        for second_index in "${!GS_MONGODB_SHARD_HOSTNAMES[@]}"; do
            [ "$second_index" -le "$first_index" ] && continue
            second_host=${GS_MONGODB_SHARD_HOSTNAMES[$second_index]}
            [ "$first_host" != "$second_host" ] ||
                gs_mongodb_die "Shard hostname '$first_host' occurs more than once."
        done
    done
}

gs_mongodb_cluster_validate_configuration