#!/bin/bash
# Smartbotic Update Script
# Updates Smartbotic services while preserving all configurations
#
# Usage:
#   sudo ./update.sh /path/to/packages/
#   sudo ./update.sh --rolling --backup /path/to/packages/

set -e

# Default paths (must match installation)
PREFIX="${PREFIX:-/opt/smartbotic}"
BINDIR="$PREFIX/bin"
CONFDIR="${CONFDIR:-/etc/smartbotic}"
DATADIR="${DATADIR:-/var/lib/smartbotic}"
BACKUP_DIR="/var/backups/smartbotic"

# Log file
UPDATE_LOG=""

# Output control
VERBOSE=false
QUIET=false

# Service order (database first - it's a dependency)
SERVICES=(
    "smartbotic-database"
    "smartbotic-microbit"
)

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m'

# Initialize logging
init_logging() {
    mkdir -p "$PREFIX"
    UPDATE_LOG="$PREFIX/update-$(date +%Y%m%d-%H%M%S).log"
    echo "Smartbotic Update Log - $(date)" > "$UPDATE_LOG"
    echo "Command: $0 $ORIGINAL_ARGS" >> "$UPDATE_LOG"
    echo "========================================" >> "$UPDATE_LOG"
}

# Log to file only
log() {
    echo "[$(date +%H:%M:%S)] $1" >> "$UPDATE_LOG"
}

# Print to console (respects quiet mode)
print_info() {
    log "INFO: $1"
    if [ "$QUIET" = false ] && [ "$VERBOSE" = true ]; then
        echo -e "${GREEN}[INFO]${NC} $1"
    fi
}

print_warn() {
    log "WARN: $1"
    if [ "$QUIET" = false ]; then
        echo -e "${YELLOW}[WARN]${NC} $1"
    fi
}

print_error() {
    log "ERROR: $1"
    echo -e "${RED}[ERROR]${NC} $1" >&2
}

# Always show steps (progress indicator)
print_step() {
    log "STEP: $1"
    if [ "$QUIET" = false ]; then
        echo -e "${BLUE}▶${NC} $1"
    fi
}

# Summary line (always shown unless quiet)
print_summary() {
    log "SUMMARY: $1"
    if [ "$QUIET" = false ]; then
        echo -e "  ${GREEN}✓${NC} $1"
    fi
}

usage() {
    cat <<EOF
Smartbotic Update Script

Usage: $0 [OPTIONS] PACKAGE_DIR

Options:
    --rolling         Rolling update (one service at a time, minimizes downtime)
    --backup          Create backup before update
    --skip-restart    Update files but don't restart services
    --no-deps         Skip dependency installation
    --dry-run         Show what would be done
    -v, --verbose     Show detailed output
    -q, --quiet       Minimal output (errors only)
    -h, --help        Show this help

Log file: Update details are logged to \$PREFIX/update-YYYYMMDD-HHMMSS.log

Examples:
    # Standard update (stops all, updates, starts all)
    sudo $0 /tmp/packages/

    # Rolling update with backup (recommended for production)
    sudo $0 --rolling --backup /tmp/packages/

    # Update without restarting (for manual control)
    sudo $0 --skip-restart /tmp/packages/
EOF
}

ROLLING=false
BACKUP=false
DRY_RUN=false
SKIP_RESTART=false
NO_DEPS=false
PACKAGE_DIR=""
ALL_DEPS=""
ORIGINAL_ARGS="$*"

while [[ $# -gt 0 ]]; do
    case $1 in
        --rolling) ROLLING=true; shift ;;
        --backup) BACKUP=true; shift ;;
        --dry-run) DRY_RUN=true; shift ;;
        --skip-restart) SKIP_RESTART=true; shift ;;
        --no-deps) NO_DEPS=true; shift ;;
        -v|--verbose) VERBOSE=true; shift ;;
        -q|--quiet) QUIET=true; shift ;;
        -h|--help) usage; exit 0 ;;
        -*) print_error "Unknown option: $1"; usage; exit 1 ;;
        *) PACKAGE_DIR="$1"; shift ;;
    esac
done

if [ -z "$PACKAGE_DIR" ]; then
    print_error "Package directory required"
    usage
    exit 1
fi

if [ ! -d "$PACKAGE_DIR" ]; then
    print_error "Package directory does not exist: $PACKAGE_DIR"
    exit 1
fi

# Check root
if [ "$EUID" -ne 0 ] && [ "$DRY_RUN" = false ]; then
    print_error "Must run as root (or use --dry-run)"
    exit 1
fi

# Run command, log output
run_cmd() {
    log "CMD: $*"
    if [ "$DRY_RUN" = true ]; then
        log "  [DRY-RUN] Skipped"
        if [ "$VERBOSE" = true ]; then
            echo "  [DRY-RUN] $*"
        fi
    else
        local output
        if output=$("$@" 2>&1); then
            if [ -n "$output" ]; then
                echo "$output" >> "$UPDATE_LOG"
            fi
        else
            local exit_code=$?
            if [ -n "$output" ]; then
                echo "$output" >> "$UPDATE_LOG"
            fi
            return $exit_code
        fi
    fi
}

# Collect dependencies from package
collect_deps() {
    local deps="$1"
    if [ -n "$deps" ]; then
        for dep in $deps; do
            if [[ ! " $ALL_DEPS " =~ " $dep " ]]; then
                ALL_DEPS="$ALL_DEPS $dep"
            fi
        done
    fi
}

# Install new dependencies
install_deps() {
    if [ "$NO_DEPS" = true ]; then
        return
    fi

    ALL_DEPS=$(echo "$ALL_DEPS" | xargs)
    if [ -z "$ALL_DEPS" ]; then
        return
    fi

    print_step "Installing dependencies..."
    log "Dependencies: $ALL_DEPS"

    if [ "$DRY_RUN" = true ]; then
        log "[DRY-RUN] apt-get update && apt-get install -y $ALL_DEPS"
    else
        apt-get update -qq >> "$UPDATE_LOG" 2>&1
        apt-get install -y --no-install-recommends $ALL_DEPS >> "$UPDATE_LOG" 2>&1
    fi
    print_summary "Dependencies installed"
}

# Create backup
create_backup() {
    if [ "$BACKUP" = false ]; then
        return
    fi

    local backup_name="backup-$(date +%Y%m%d-%H%M%S)"
    local backup_path="$BACKUP_DIR/$backup_name"

    print_step "Creating backup..."
    log "Backup path: $backup_path"

    run_cmd mkdir -p "$backup_path"
    run_cmd cp -a "$PREFIX" "$backup_path/opt-smartbotic"
    run_cmd cp -a "$CONFDIR" "$backup_path/etc-smartbotic"

    # Save current versions
    if [ "$DRY_RUN" = false ]; then
        for service in "${SERVICES[@]}"; do
            local binary="$BINDIR/$service"
            if [ -f "$binary" ]; then
                echo "$service: $(md5sum "$binary" | cut -d' ' -f1)" >> "$backup_path/versions.txt"
            fi
        done
    fi

    print_summary "Backup: $backup_path"
}

# Stop a service gracefully
stop_service() {
    local service="$1"

    if systemctl is-active --quiet "$service" 2>/dev/null; then
        log "Stopping $service..."
        run_cmd systemctl stop "$service"
        if [ "$DRY_RUN" = false ]; then
            sleep 2
        fi
    fi
}

# Start a service
start_service() {
    local service="$1"

    if systemctl is-enabled --quiet "$service" 2>/dev/null; then
        log "Starting $service..."
        run_cmd systemctl start "$service"

        if [ "$DRY_RUN" = false ]; then
            sleep 3
            if ! systemctl is-active --quiet "$service"; then
                print_error "$service failed to start! Check: journalctl -u $service -n 50"
                log "Service $service failed to start"
                return 1
            fi
            log "$service started successfully"
        fi
    else
        log "$service is not enabled, skipping start"
    fi
}

# Update a single service
update_service() {
    local service="$1"
    local service_name="${service#smartbotic-}"

    local pkg
    pkg=$(find "$PACKAGE_DIR" -name "$service-*.tar.gz" -type f | head -1)

    if [ -z "$pkg" ]; then
        log "No package found for $service, skipping"
        return 0
    fi

    print_step "Updating $service_name..."

    if [ "$ROLLING" = true ] && [ "$SKIP_RESTART" = false ]; then
        stop_service "$service"
    fi

    local tmpdir
    tmpdir=$(mktemp -d)

    tar -xzf "$pkg" -C "$tmpdir"
    local pkg_root
    pkg_root=$(find "$tmpdir" -maxdepth 1 -type d ! -path "$tmpdir" | head -1)

    # Update binary
    if [ -f "$pkg_root/bin/$service" ]; then
        log "Installing new binary..."
        run_cmd install -m 755 "$pkg_root/bin/$service" "$BINDIR/$service"
    fi

    # Update management scripts
    for script_bin in "$pkg_root/bin"/smartbotic-install "$pkg_root/bin"/smartbotic-update "$pkg_root/bin"/smartbotic-setup-nginx; do
        if [ -f "$script_bin" ]; then
            local script_name=$(basename "$script_bin")
            log "Updating script: $script_name"
            run_cmd install -m 755 "$script_bin" "$BINDIR/$script_name"
        fi
    done

    # Update systemd service file
    if [ -d "$pkg_root/etc/systemd/system" ]; then
        for svc_file in "$pkg_root/etc/systemd/system"/*.service; do
            if [ -f "$svc_file" ]; then
                log "Updating systemd service..."
                run_cmd install -m 644 "$svc_file" "/etc/systemd/system/"
            fi
        done
    fi

    # Check for new config defaults (never overwrite)
    if [ -d "$pkg_root/etc/smartbotic" ]; then
        for cfg in "$pkg_root/etc/smartbotic"/*; do
            local cfg_name=$(basename "$cfg")
            local dest_name="${cfg_name%.default}"
            local dest="$CONFDIR/$dest_name"

            if [ -f "$dest" ]; then
                if ! diff -q "$cfg" "$dest" > /dev/null 2>&1; then
                    log "New config default available: $dest_name.new"
                    run_cmd cp "$cfg" "$dest.new"
                fi
            fi
        done
    fi

    # Update data files (migrations, nginx template)
    if [ -d "$pkg_root/share/smartbotic" ]; then
        if [ -d "$pkg_root/share/smartbotic/database/migrations" ] && [ "$DRY_RUN" = false ]; then
            log "Updating database migrations..."
            cp -a "$pkg_root/share/smartbotic/database/migrations"/* "$DATADIR/database/migrations/" 2>/dev/null || true
            chown -R smartbotic:smartbotic "$DATADIR/database/migrations"
        fi
        if [ -d "$pkg_root/share/smartbotic/nginx" ] && [ "$DRY_RUN" = false ]; then
            log "Updating nginx template..."
            cp -a "$pkg_root/share/smartbotic/nginx"/* "$PREFIX/share/smartbotic/nginx/" 2>/dev/null || true
        fi
    fi

    rm -rf "$tmpdir"

    if [ "$ROLLING" = true ] && [ "$SKIP_RESTART" = false ]; then
        start_service "$service"
    fi

    print_summary "$service_name updated"
}

# Update WebUI
update_webui() {
    local pkg
    pkg=$(find "$PACKAGE_DIR" -name "smartbotic-webui-*.tar.gz" -type f | head -1)

    if [ -z "$pkg" ]; then
        log "No WebUI package found, skipping"
        return
    fi

    print_step "Updating webui..."

    local tmpdir
    tmpdir=$(mktemp -d)
    trap "rm -rf '$tmpdir'" RETURN

    tar -xzf "$pkg" -C "$tmpdir"
    local pkg_root
    pkg_root=$(find "$tmpdir" -maxdepth 1 -type d ! -path "$tmpdir" | head -1)

    if [ -d "$pkg_root/share/smartbotic/webui" ]; then
        log "Installing WebUI files..."
        if [ "$DRY_RUN" = false ]; then
            rm -rf "$DATADIR/microbit/webui"/*
            cp -a "$pkg_root/share/smartbotic/webui"/* "$DATADIR/microbit/webui/"
            chown -R smartbotic:smartbotic "$DATADIR/microbit/webui"
        fi
    fi

    print_summary "WebUI updated"
}

# Main
main() {
    # Initialize logging
    init_logging

    if [ "$QUIET" = false ]; then
        echo ""
        echo -e "${GREEN}Smartbotic Update${NC}"
        echo "================="
    fi

    log "Package dir: $PACKAGE_DIR"
    log "Rolling: $ROLLING"
    log "Backup: $BACKUP"

    if [ "$DRY_RUN" = true ]; then
        print_warn "DRY-RUN MODE - no changes will be made"
    fi

    # Create backup if requested
    create_backup

    # Collect dependencies from all packages
    print_step "Checking packages..."
    local pkg_count=0
    for pkg in "$PACKAGE_DIR"/smartbotic-*.tar.gz; do
        if [ -f "$pkg" ]; then
            pkg_count=$((pkg_count + 1))
            local tmpdir=$(mktemp -d)
            tar -xzf "$pkg" -C "$tmpdir" 2>/dev/null
            local pkg_root=$(find "$tmpdir" -maxdepth 1 -type d ! -path "$tmpdir" | head -1)
            if [ -f "$pkg_root/DEPS" ]; then
                collect_deps "$(cat "$pkg_root/DEPS")"
            fi
            rm -rf "$tmpdir"
        fi
    done
    print_summary "Found $pkg_count packages"

    install_deps

    if [ "$ROLLING" = false ] && [ "$SKIP_RESTART" = false ]; then
        # Stop all services in reverse order
        print_step "Stopping services..."
        for service in $(printf '%s\n' "${SERVICES[@]}" | tac); do
            stop_service "$service"
        done
        print_summary "Services stopped"
    fi

    # Update each service
    for service in "${SERVICES[@]}"; do
        update_service "$service"
    done

    # Update WebUI
    update_webui

    # Reload systemd
    print_step "Finalizing..."
    run_cmd systemctl daemon-reload

    if [ "$ROLLING" = false ] && [ "$SKIP_RESTART" = false ]; then
        # Start all services
        print_step "Starting services..."
        for service in "${SERVICES[@]}"; do
            start_service "$service"
        done
        print_summary "Services started"
    fi

    print_summary "Update complete"

    if [ "$QUIET" = false ]; then
        echo ""
        echo -e "${GREEN}Done!${NC} Log: $UPDATE_LOG"
        echo ""
        echo "Verify:"
        echo "  systemctl status smartbotic-database smartbotic-microbit"
        echo "  journalctl -u smartbotic-microbit -f"
        echo ""
    fi

    log "Update completed successfully"
}

main