#!/usr/bin/env sh

# Adjustable parameters
## The number of backups to keep
BACKUPS_KEEP=24

# Global variables (Do NOT change)
CLEANUP_FABRIC=false
CLEANUP_LUCKPERMS=false
CLEANUP_PAPER=false

main() {
    log_info "=== Backup run started at $(date -u '+%Y-%m-%dT%H:%M:%SZ') ==="
    log_info "Keeping last $BACKUPS_KEEP backups"

    check_root_permissions
    init_backup

    broadcast_status started

    backup_bluemap || cleanup_failure
    backup_fabric || cleanup_failure
    backup_luckperms || cleanup_failure
    backup_paper || cleanup_failure
    backup_schematics || cleanup_failure
    backup_velocity || cleanup_failure

    finalize_backup || cleanup_failure
    prune_backups
    cleanup_success

    broadcast_status finished

    log_info "=== Backup run completed successfully at $(date -u '+%Y-%m-%dT%H:%M:%SZ') ==="
}

check_root_permissions() {
    if [ "$EUID" -ne 0 ]; then
      log_error "This script must be run by the root user"
      exit 1
    fi

    log_info "Running as root (EUID=$EUID)"
}

init_backup() {
    BACKUP_ID="$(date -u +%Y-%m-%dT%H-%M-%SZ)"
    BACKUP_DIR="/backups/$BACKUP_ID"

    log_info "Creating backup directory: $BACKUP_DIR"

    docker compose run --rm init sh -c '
        mkdir -p "$1" &&
        chown minecraft_server:minecraft_server "$1"
    ' -- "$BACKUP_DIR" || {
        log_error "Failed to create backup directory $BACKUP_DIR"
        exit 1
    }

    log_info "Backup directory created and ownership set"
}

broadcast_status() {
    STATUS="$1"
    log_info "Broadcasting backup status: $STATUS"

    if docker compose exec -T fabric true > /dev/null 2>&1; then
        docker compose exec -T fabric rcon-cli "tellraw @a [{\"text\":\"Server\",\"color\":\"light_purple\"},{\"text\":\": Backup $STATUS.\",\"color\":\"white\"}]" > /dev/null 2>&1
    fi
    if docker compose exec -T paper true > /dev/null 2>&1; then
        docker compose exec -T paper rcon-cli "tellraw @a [{\"text\":\"Server\",\"color\":\"light_purple\"},{\"text\":\": Backup $STATUS.\",\"color\":\"white\"}]" > /dev/null 2>&1
    fi
}

backup_bluemap() {
    log_info "Starting Bluemap backup..."

    docker compose run --rm init sh -c '
        cp -a --reflink=auto /bluemap_data "$1" &&
        cp -a --reflink=auto /bluemap_maps "$1" &&
        cp -a --reflink=auto /bluemap_web "$1"
    ' -- "$BACKUP_DIR" || return 1

    log_info "Finished Bluemap backup"
}

backup_fabric() {
    log_info "Starting Fabric backup..."

    CLEANUP_FABRIC=false
    if docker compose exec -T fabric true > /dev/null 2>&1; then
        CLEANUP_FABRIC=true
        log_info "Fabric server detected, disabling saves"

        docker compose exec -T fabric rcon-cli save-off > /dev/null 2>&1
        docker compose exec -T fabric rcon-cli save-all > /dev/null 2>&1
    fi

    docker compose run --rm init sh -c '
        mkdir -p "$1"/fabric_data &&
        cp -a --reflink=auto /fabric_data/g4mespeed "$1"/fabric_data &&
        cp -a --reflink=auto /fabric_data/fabric-essentials.json "$1"/fabric_data &&
        cp -a --reflink=auto /fabric_data/world "$1"/fabric_data
    ' -- "$BACKUP_DIR" || return 1

    log_info "Finished Fabric backup"
}

backup_luckperms() {
    log_info "Starting LuckPerms backup..."

    CLEANUP_LUCKPERMS=false
    if ! docker compose exec -T luckperms true > /dev/null 2>&1; then
        CLEANUP_LUCKPERMS=true
        log_info "LuckPerms not running, starting temporary container"

        docker compose up --wait luckperms > /dev/null 2>&1
    fi

    docker compose exec luckperms sh -c '
        pg_dump -U luckperms luckperms > "$1"/luckperms.sql
    ' -- "$BACKUP_DIR" || return 1

    log_info "Finished LuckPerms backup"
}

backup_paper() {
    log_info "Starting Paper backup..."

    CLEANUP_PAPER=false
    if docker compose exec -T paper true > /dev/null 2>&1; then
        CLEANUP_PAPER=true
        log_info "Paper server detected, disabling saves"

        docker compose exec -T paper rcon-cli save-off > /dev/null 2>&1
        docker compose exec -T paper rcon-cli save-all > /dev/null 2>&1
    fi

    docker compose run --rm init sh -c '
        mkdir -p "$1"/paper_data/plugins/PlotSquared &&
        cp -a --reflink=auto /paper_data/plugins/Multiverse-Inventories "$1"/paper_data/plugins &&
        cp -a --reflink=auto /paper_data/plugins/Essentials "$1"/paper_data/plugins &&
        cp -a --reflink=auto /paper_data/plugins/PlotSquared/backups "$1"/paper_data/plugins/PlotSquared &&
        cp -a --reflink=auto /paper_data/creative "$1"/paper_data &&
        cp -a --reflink=auto /paper_data/creative_nether "$1"/paper_data &&
        cp -a --reflink=auto /paper_data/survival "$1"/paper_data &&
        cp -a --reflink=auto /paper_data/survival_nether "$1"/paper_data &&
        cp -a --reflink=auto /paper_data/survival_the_end "$1"/paper_data
    ' -- "$BACKUP_DIR" || return 1

    docker compose run --rm sqlite_helper \
        /paper_data/plugins/PlotSquared/storage.db \
        ".backup $BACKUP_DIR/paper_data/plugins/PlotSquared/storage.db" || return 1

    docker compose run --rm sqlite_helper \
        /paper_data/plugins/PlotSquared/user_cache.db \
        ".backup $BACKUP_DIR/paper_data/plugins/PlotSquared/user_cache.db" || return 1

    log_info "Finished Paper backup"
}

backup_schematics() {
    log_info "Starting schematics backup..."

    docker compose run --rm init sh -c '
        cp -a --reflink=auto /schematics "$1"
    ' -- "$BACKUP_DIR" || return 1

    log_info "Finished schematics backup"
}

backup_velocity() {
    log_info "Starting Velocity backup..."

    docker compose run --rm init sh -c 'mkdir -p "$1"/velocity_data/plugins/dclink-velocity' -- "$BACKUP_DIR" || return 1

    docker compose run --rm sqlite_helper \
        /velocity_data/plugins/dclink-velocity/dclink.db \
        ".backup $BACKUP_DIR/velocity_data/plugins/dclink-velocity/dclink.db" || return 1

    log_info "Finished Velocity backup"
}

finalize_backup() {
    log_info "Finalizing backup $BACKUP_ID"

    docker compose run --rm init chown -R minecraft_server:minecraft_server "$BACKUP_DIR" || {
        log_error "Failed to update ownership of backup files"
        return 1
    }

    log_info "Backup ownership updated"

    docker compose run --rm init sh -c '
        ln -sfn "$1" /backups/.latest_tmp &&
        mv -Tf /backups/.latest_tmp /backups/latest
    ' -- "$BACKUP_DIR" || {
        log_error "Failed to update /backups/latest symlink"
        return 1
    }

    log_info "Updated /backups/latest symlink"
}

prune_backups() {
    BACKUPS_ALL=$(docker compose run --rm init sh -c '
        find /backups -mindepth 1 -maxdepth 1 -type d \
        -name "????-??-??T??-??-??Z" | sort
    ')

    BACKUPS_TOTAL=$(echo "$BACKUPS_ALL" | wc -l)
    BACKUPS_PRUNE=$((BACKUPS_TOTAL - BACKUPS_KEEP))

    [ "$BACKUPS_PRUNE" -le 0 ] && BACKUPS_PRUNE=0

    log_info "Total backups found: $BACKUPS_TOTAL"
    log_info "Backups to prune: $BACKUPS_PRUNE"

    echo "$BACKUPS_ALL" | head -n "$BACKUPS_PRUNE" | while read -r OLD_BACKUP_DIR; do
        log_info "Removing old backup: $OLD_BACKUP_DIR"
        docker compose run --rm init rm -rf "$OLD_BACKUP_DIR"
    done
}

trap cleanup_trap HUP INT QUIT ABRT TERM
cleanup_trap() {
    log_info "Backup cancelled by signal"
    broadcast_status cancelled
    cleanup
    delete_backup
    exit 0
}

cleanup_failure() {
    log_info "Running cleanup due to failure"
    broadcast_status failed
    cleanup
    delete_backup
    exit 1
}

cleanup_success() {
    log_info "Running cleanup"
    cleanup
}

cleanup() {
    # Ignore specified conditions to ensure cleanup runs to completion uninterrupted
    trap '' HUP INT QUIT ABRT TERM

    if [ "$CLEANUP_FABRIC" = true ]; then
        log_info "Re-enabling Fabric saves"
        docker compose exec -T fabric rcon-cli save-on > /dev/null 2>&1
    fi

    if [ "$CLEANUP_LUCKPERMS" = true ]; then
        log_info "Bringing down temporary LuckPerms container"
        docker compose stop luckperms > /dev/null 2>&1
    fi

    if [ "$CLEANUP_PAPER" = true ]; then
        log_info "Re-enabling Paper saves"
        docker compose exec -T paper rcon-cli save-on > /dev/null 2>&1
    fi
}

delete_backup() {
    if ! docker compose run --rm init rm -rf "$BACKUP_DIR"; then
        log_error "Failed to remove $BACKUP_DIR"
    fi
}

log_info() {
    echo "[$(date -u '+%Y-%m-%dT%H:%M:%SZ')] INFO: $*"
}

log_error() {
    echo "[$(date -u '+%Y-%m-%dT%H:%M:%SZ')] ERROR: $*" >&2
}

main