#!/bin/bash
set -euo pipefail

ARTIFACT_DIR="/opt/api-artifacts"
CURRENT_LINK="$ARTIFACT_DIR/current"
BLUE_LINK="$ARTIFACT_DIR/blue"
GREEN_LINK="$ARTIFACT_DIR/green"
SERVICE_NAME="api-server.service"

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

log_info() { echo -e "${GREEN}[INFO]${NC} $1"; }
log_warn() { echo -e "${YELLOW}[WARN]${NC} $1"; }
log_error() { echo -e "${RED}[ERROR]${NC} $1"; }

if [ -L "$CURRENT_LINK" ]; then
    CURRENT_TARGET=$(readlink "$CURRENT_LINK")
    if [ "$CURRENT_TARGET" = "blue" ]; then
        NEW_TARGET="green"
    else
        NEW_TARGET="blue"
    fi
else
    NEW_TARGET="blue"
fi

NEW_TARGET_LINK="$ARTIFACT_DIR/$NEW_TARGET"

if [ ! -L "$NEW_TARGET_LINK" ]; then
    log_error "Target deployment not found: $NEW_TARGET_LINK"
    log_error "Run deploy.sh first"
    exit 1
fi

NEW_BUILD=$(readlink "$NEW_TARGET_LINK")
log_info "Promoting $NEW_TARGET to production"
log_info "New build: $NEW_BUILD"

read -p "Continue with promotion? (yes/no): " -r
if [[ ! $REPLY =~ ^[Yy][Ee][Ss]$ ]]; then
    log_warn "Promotion cancelled"
    exit 0
fi

log_info "Switching current symlink to $NEW_TARGET"
ln -sfn "$NEW_TARGET" "$CURRENT_LINK"

log_info "Reloading systemd service..."
systemctl reload-or-restart "$SERVICE_NAME"

sleep 5

log_info "Running health check..."
if "$ARTIFACT_DIR/scripts/health-check.sh"; then
    log_info "Promotion successful!"
    log_info "Active deployment: $NEW_TARGET ($NEW_BUILD)"
else
    log_error "Health check failed after promotion!"
    log_warn "Run rollback.sh to revert"
    exit 1
fi