#!/bin/bash

#########################################################
# Options                                               #
#########################################################

set -e
set -o pipefail

#########################################################
# Globals                                               #
#########################################################

readonly GITLAB_URI="https://git.pleroma.social"
readonly PREFIX_API="api/v4/projects/pleroma%2Fpleroma/repository"
readonly ENDPOINT_REPO="pleroma/pleroma.git"
readonly ENDPOINT_FILE="pleroma/pleroma/raw"
readonly ENDPOINT_LIST="pleroma/pleroma/files"
readonly ENDPOINT_TAG="$PREFIX_API/tags"
readonly ENDPOINT_BLOB="$PREFIX_API/blobs"
readonly ENDPOINT_BRANCH="$PREFIX_API/branches"

flags=""

#########################################################
# Helpers                                               #
#########################################################

has_command() {
    if command -v 1>/dev/null 2>&1 "$1"; then
        return 0
    else
        return 1
    fi
}

require_command() {
    if ! has_command "$1"; then
        printf "\nError: This action requires the command '%s' in your PATH.\n" "$1"
        exit 1
    fi
}

require_file() {
    if [[ ! -f $1 ]]; then
        echo "File missing: '$1' (Example at: '$2')"
        FILE_FAILED=1
    fi
}

throw_file_errors() {
    if [[ -n "$FILE_FAILED" ]]; then
        echo ""
        echo "Please create the missing files first."
        echo "The script will now exit."
        exit 1
    fi
}

render_template() {
    require_command m4
    require_command awk

    m4 $flags docker-compose.m4 | awk 'NF'
}

docker_compose() {
    require_command docker-compose

    docker-compose \
        -f <(render_template) \
        --project-directory . \
        "$@"
}

load_env() {
    while read -r line; do
        if [[ "$line" == \#* ]] || [[ -z "$line" ]]; then
            continue;
        fi

        export "${line?}"
        flags="-D__${line?} $flags"
    done < .env
}

download_file() { # $1: source, $2: target
    if has_command curl; then
        curl -sSL "$1" -o "$2"
    elif has_command wget; then
        wget "$1" -O "$2"
    else
        printf "\nError: This action requires either curl or wget in your PATH.\n"
        exit 1
    fi
}

request_file_content() { # $1: source
    if has_command curl; then
        curl -sSL "$1"
    elif has_command wget; then
        wget "$1" -O- 2>/dev/null
    else
        printf "\nError: This action requires either curl or wget in your PATH.\n"
        exit 1
    fi
}

#########################################################
# Subcommands                                           #
#########################################################

action__build() {
    local cacheTag=""

    # Alternative 1: Get tags or branches from git (if installed)
    if [[ -z "$cacheTag" ]] && has_command git && has_command grep && has_command awk; then
        set +o pipefail
        local resolvedHash
        resolvedHash="$(git ls-remote $GITLAB_URI/$ENDPOINT_REPO | grep "/$PLEROMA_VERSION" | awk '{ print $1 }')"
        set -o pipefail

        if [[ -n "$resolvedHash" ]]; then
            cacheTag="$resolvedHash"
        fi
    fi

    # Alternative 2: Current time
    if [[ -z "$cacheTag" ]] && has_command date; then
        echo ""
        echo "WARNING WARNING WARNING"
        echo ""
        echo "You don't have git installed, so we cannot know if the cache is up to date."
        echo "We'll use the current unix timestamp as a replacement value,"
        echo "but this means that your cache is always 'stale' and docker wastes your time."
        echo ""
        echo "WARNING WARNING WARNING"
        echo ""
        echo "Waiting 5 seconds to make sure you notice this..."
        sleep 5

        cacheTag="$(date '+%s')"
    fi

    # Alternative 3: Random number with awk
    if [[ -z "$cacheTag" ]] && [[ -n "$RANDOM" ]]; then
        echo ""
        echo "WARNING WARNING WARNING"
        echo ""
        echo "You don't have git installed, so we cannot know if the cache is up to date."
        echo "Additionally you don't have \`date\` available. (What kind of pc is this?!)"
        echo "This means we cannot set any unique value as cache tag."
        echo ""
        echo "We'll generate a random number to try and mark the cache as 'always stale'."
        echo "Hoewever: Depending on your shell this might not always work, or only work a few times."
        echo ""
        echo "You should *really* get this fixed unless you know what you're doing."
        echo ""
        echo "WARNING WARNING WARNING"
        echo ""
        echo "Waiting 5 seconds to make sure you notice this..."
        sleep 5

        cacheTag="$RANDOM"
    fi

    # Last resort: Constant value
    if [[ -z "$cacheTag" ]]; then
        echo ""
        echo "WARNING WARNING WARNING"
        echo ""
        echo "You don't have git installed, so we cannot know if the cache is up to date."
        echo "Additionally you don't have \`date\` available, and your shell refuses to generate random numbers."
        echo "This means we cannot set any unique or random value as cache tag."
        echo "Consequently your cache will always be 'fresh' and you never get updates."
        echo ""
        echo "You can work around this by running \`docker system prune\` to throw away the build cache,"
        echo "but you should *really* get this fixed unless you know what you're doing."
        echo ""
        echo "WARNING WARNING WARNING"
        echo ""
        echo "Waiting 5 seconds to make sure you notice this..."
        sleep 5

        cacheTag="broken-host-env"
    fi

    echo -e "#> (Re-)Building with cache tag \`${cacheTag}\`...\n"

    docker_compose build --build-arg __CACHE_TAG="$cacheTag" server
}

action__dump() {
    cat <(render_template)
}

action__enter() {
    docker_compose exec server sh -c 'cd ~/pleroma && bash'
}

action__logs() {
    docker_compose logs "$@"
}

action__mix() {
    docker_compose exec server sh -c "cd ~/pleroma && mix $*"
}

action__passthrough() {
    docker_compose "$@"
}

action__p() {
    action__passthrough "$@"
}

action__restart() {
    action__stop
    action__start
}

action__start() {
    docker_compose up --remove-orphans -d
}

action__up() {
    action__start
}

action__stop() {
    docker_compose down
}

action__down() {
    action__stop
}

action__status() {
    docker_compose ps
}

action__ps() {
    action__status
}

action__debug() {
    require_command xhost

    local debug_mounts
    debug_mounts="
        -v $(pwd)/custom.d:/custom.d \
        -v $(pwd)/debug.d/build:/home/pleroma/pleroma/_build \
        -v $(pwd)/debug.d/deps:/home/pleroma/pleroma/deps \
    "

    if [[ ! -d ./debug.d ]]; then
        mkdir -p ./debug.d/{build,deps}
    fi

    if [[ ! -d ./custom.d/lib ]]; then
        mkdir -p ./custom.d/lib
    fi

    action__stop

    docker_compose run --rm -u pleroma -w /home/pleroma/pleroma "$debug_mounts" server bash -c 'cp -rvf /custom.d/* /home/pleroma/pleroma && mix deps.get'

    local x_flags=""
    if [[ $NO_X_FORWARDING != 1 ]]; then
        x_flags="-e DISPLAY=$DISPLAY -v /tmp/.X11-unix:/tmp/.X11-unix"
    fi

    [[ $NO_X_FORWARDING == 1 ]] || xhost +local:root
    docker_compose run --rm -u pleroma -w /home/pleroma/pleroma "$debug_mounts" "$x_flags" server bash -c "cp -rvf /custom.d/* /home/pleroma/pleroma && $*"
    [[ $NO_X_FORWARDING == 1 ]] || xhost -local:root
}

action__mod() {
    require_command dialog
    require_command jq
    require_command curl

    if [[ ! -d ./debug.d ]]; then
        mkdir ./debug.d
    fi

    if [[ ! -f ./debug.d/mod_files.json ]] || [[ -n "$(find ./debug.d/mod_files.json -mmin +5)" ]]; then
        curl -sSL -# "$GITLAB_URI/$ENDPOINT_LIST/$PLEROMA_VERSION?format=json" > ./debug.d/mod_files.json

        if [[ -f ./debug.d/mod_files.lst ]]; then
            rm ./debug.d/mod_files.lst
        fi

        jq -r 'map("\(.)\n") | add' <./debug.d/mod_files.json >./debug.d/mod_files.lst
    fi

    if [[ -f ./debug.d/mod_files.lst ]] && [[ -r ./debug.d/mod_files.lst ]]; then
        choices=""

        while read -r candidate; do
            choices="$choices $candidate $(echo "$candidate" | rev | cut -d/ -f1 | rev)"
        done <<< "$(grep -E ".*$1.*" <./debug.d/mod_files.lst)"

        res=$(mktemp)
        dialog --menu "Select the file you want to modify:" 35 80 30 $choices 2>"$res"
        choice=$(cat "$res")

        install -D <(echo '') "./custom.d/$choice"
        curl -sSL -# "$GITLAB_URI/$ENDPOINT_FILE/$PLEROMA_VERSION/$choice" > "./custom.d/$choice"
    else
        install -D <(echo '') "./custom.d/$1"
        curl -sSL -# "$GITLAB_URI/$ENDPOINT_FILE/$PLEROMA_VERSION/$1" > "./custom.d/$1"
    fi
}

action__cp() {
    container="$(docker_compose ps -q server)"

    echo "$container:$1 -> $2"
    docker cp "$container:$1" "$2"
}

#########################################################
# Help                                                  #
#########################################################

print_help() {
    echo "
Pleroma Maintenance Script

Usage:
    $0 [action] [action-args...]

Actions:
    build                        (Re)build the pleroma container.

    dump                         Dump the generated docker-compose.yml to stdout.

    debug [bin] [args...]        Launches a new pleroma container but uses \$bin instead of phx.server as entrypoint.
                                 **Warning**: This is intended for debugging pleroma with tools like :debugger and :observer.
                                 It thus forwards your X-Server into docker and temporarily fiddles with your xhost
                                 access controls. If this is a security concern for you, please export NO_X_FORWARDING=1
                                 before launching a debugger session.

    enter                        Spawn a shell inside the container for debugging/maintenance.
                                 This command does not link to the postgres container.
                                 If you need that use #debug instead.

    logs                         Show the current container logs.

    mix [task] [args...]         Run a mix task without entering the container.

    mod [file]                   Creates the file in custom.d and downloads the content from pleroma.social.
                                 The download respects your \$PLEROMA_VERSION from .env.

    passthrough / p [...]        Pass any custom command to docker-compose.

    restart                      Executes #stop and #start respectively.

    start / up                   Start pleroma and sibling services.

    stop / down                  Stop pleroma and sibling services.

    status / ps                  Show the current container status.

    copy / cp [source] [target]  Copy a file from your pc to the pleroma container.
                                 This operation only works in one direction.
                                 For making permanent changes to the container use custom.d.

Environment:
    DEBUG can be used to modify the loglevel.
        DEBUG=1 prints all commands before they are executed.
        DEBUG=2 prints all bash statements before they are executed (a lot).

    SHOPT can be used to modify shell options.
        Pass a list of options to this variable like SHOPT='-x -e'.
        For setting long options with -o use a colon (:) instead of a space
        to seperate the option from -o. For example: SHOPT='-x -e -o:pipefail'.

Contributing:
    You can report bugs or contribute to this project at:
        https://glitch.sh/sn0w/pleroma-docker
"
}

#########################################################
# Main                                                  #
#########################################################

# Check if there is any command at all
if [[ -z "$1" ]]; then
    print_help
    exit 1
fi

# Check for SHOPTs
if [[ -n "$SHOPT" ]]; then
    for opt in $SHOPT; do
        if [[ $opt =~ ":" ]]; then
            set -o "${opt//-o:/}"
        else
            set "$opt"
        fi
    done
fi

# Check for DEBUG
if [[ -n "$DEBUG" ]]; then
    if [[ $DEBUG == 1 ]]; then
        export DEBUG_COMMANDS=1
    elif [[ $DEBUG == 2 ]]; then
        set -x
    fi
fi

# Check if the option is "help"
case "$1" in
    "help"|"h"|"--help"|"-h"|"-?")
        print_help
        exit 0
    ;;
esac

# Check if the called command exists
func="action__${1}"
if ! type -t "$func" 1>/dev/null 2>&1; then
    echo "Unknown flag or subcommand."
    echo "Try '$0 help'"
    exit 1
fi

# Fail if mandatory files are missing
require_file ".env" ".env.dist"
require_file "config.exs" "config.dist.exs"
throw_file_errors

# Parse .env
load_env

# Handle DEBUG=2
[[ $DEBUG != 1 ]] || set -x

# Jump to called function
shift
$func "$@"

# Disable debug mode
{ [[ $DEBUG != 1 ]] || set +x; } 2>/dev/null