#!/bin/bash
# Rollback procedures for fetch_ml deployments

set -e

REPO_ROOT=$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)
DEPLOYMENTS_DIR="${REPO_ROOT}/deployments"

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

print_success() { echo -e "${GREEN}[OK]${NC} $1"; }
print_error() { echo -e "${RED}[ERROR]${NC} $1"; }
print_warn() { echo -e "${YELLOW}[WARN]${NC} $1"; }
print_info() { echo -e "[INFO] $1"; }

show_usage() {
    echo "Usage: $0 [ENVIRONMENT]"
    echo ""
    echo "Environments:"
    echo "  staging     Rollback staging environment"
    echo "  prod        Rollback production environment"
    echo ""
    echo "Examples:"
    echo "  $0 staging     # Rollback staging"
    echo "  $0 prod        # Rollback production (requires confirmation)"
}

rollback_environment() {
    local env=$1
    local compose_file

    case $env in
        staging)
            compose_file="${DEPLOYMENTS_DIR}/docker compose.staging.yml"
            ;;
        prod)
            compose_file="${DEPLOYMENTS_DIR}/docker compose.prod.yml"
            ;;
        *)
            print_error "Unknown environment: $env"
            show_usage
            exit 1
            ;;
    esac

    if [ ! -f "$compose_file" ]; then
        print_error "Compose file not found: $compose_file"
        exit 1
    fi

    print_warn "Rolling back ${env} environment..."
    print_warn "⚠ This rolls back the image only - queue state and audit log are NOT rolled back"

    if [ "$env" = "prod" ]; then
        print_warn "⚠ CRITICAL: Production rollback"
        print_warn "⚠ Queue state is NOT rolled back"
        print_warn "⚠ Audit log chain is NOT rolled back (must never break chain)"
        print_warn "⚠ New artifacts remain in storage"
        read -p "CONFIRM PRODUCTION ROLLBACK? [yes/N] " confirm
        if [ "$confirm" != "yes" ]; then
            print_error "Rollback cancelled"
            exit 1
        fi
    else
        read -p "Continue with rollback? [y/N] " confirm
        if [ "$confirm" != "y" ]; then
            print_error "Rollback cancelled"
            exit 1
        fi
    fi

    # Get previous deployment info from audit log
    local log_file="${DEPLOYMENTS_DIR}/.${env}-audit.log"
    local previous_sha=""

    if [ -f "$log_file" ]; then
        previous_sha=$(tail -2 "$log_file" | head -1 | grep -o 'sha-[a-f0-9]*' || echo "")
        if [ -n "$previous_sha" ]; then
            print_info "Previous deployment: $previous_sha"
        fi
    fi

    # Perform rollback
    print_info "Stopping ${env} environment..."
    docker compose -f "$compose_file" down

    print_info "Starting ${env} environment..."
    docker compose -f "$compose_file" up -d

    # Log the rollback
    echo "$(date -Iseconds) | rollback | ${env} | actor=$(whoami)" >> "$log_file" 2>/dev/null || true

    print_success "${env} rollback complete!"
    print_info "Verify health with: ./scripts/deploy/health-check.sh ${env}"
}

main() {
    if [ $# -ne 1 ]; then
        show_usage
        exit 1
    fi

    rollback_environment "$1"
}

main "$@"