#!/bin/bash
set -euo pipefail

# Blue-Green deployment script with versioned releases
# Usage: ./deploy-blue-green.sh

# Source common functions
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
source "${SCRIPT_DIR}/common-lib.sh"

# Validate required environment variables
require_var "DOCKER_HOST"
require_var "REPO_PROJECT_PATH"
require_var "REPO_NAME_ONLY"
require_var "REPO"
require_var "IMAGE_TAR"
require_var "ENV_FILE_BASE64"
require_var "CF_PEM_CERT"
require_var "CF_PEM_CA"
require_var "PROD"
require_var "PRODUCTION_DOMAIN"
require_var "STAGING_DOMAIN"
require_var "REPLICA_COUNT"

validate_deployment_env

echo "⚙️ Docker host: $DOCKER_HOST"

# Generate deployment timestamp
DEPLOYMENT_TIMESTAMP=$(date +%Y%m%d_%H%M%S)
NEW_RELEASE_PATH="${RELEASES_PATH}/${DEPLOYMENT_TIMESTAMP}"

# Use Git SHA for image tag (if available, otherwise use timestamp)
if [ -n "${GIT_SHA:-}" ]; then
    IMAGE_TAG="sha-${GIT_SHA:0:7}"
else
    # Fallback for local testing without GIT_SHA
    IMAGE_TAG="local-${DEPLOYMENT_TIMESTAMP}"
fi

# Check for deployment in progress
if is_deployment_in_progress; then
    echo "⚠️ ERROR: Deployment appears to be in progress (both colors are running)"
    echo "   This might indicate a previous deployment didn't complete properly."
    echo "   Please check the deployment status and clean up any old containers."
    echo "   If you are sure that the deployment is complete, you can run the following command to clean up the old containers:"
    echo "   ssh deploy 'docker compose -p pkmntrade-club-blue down && docker compose -p pkmntrade-club-green down'"
    exit 1
fi

# Get current and new colors
CURRENT_COLOR=$(get_current_color)
NEW_COLOR=$(switch_color "$CURRENT_COLOR")

echo "📅 Deployment version: ${DEPLOYMENT_TIMESTAMP}"
echo "🏷️  Image tag: ${IMAGE_TAG}"
echo "🎨 Current: $CURRENT_COLOR → New: $NEW_COLOR"

echo "🚀 Enable and start docker service"
retry run_on_target "sudo systemctl enable --now docker.service"

echo "💾 Load the new docker image ($IMAGE_TAR)"
if [ ! -f "$IMAGE_TAR" ]; then
    echo "Error: Docker image tar file not found: $IMAGE_TAR"
    exit 1
fi

# Load the image - Docker handles the transfer via DOCKER_HOST
echo "📦 Loading Docker image..."
#retry docker load -i "$IMAGE_TAR"

# Verify the expected image exists
echo "🔍 Verifying image ${REPO}:${IMAGE_TAG} exists..."
if ! docker images -q "${REPO}:${IMAGE_TAG}" | grep -q .; then
    echo "❌ Expected image tag ${IMAGE_TAG} not found!"
    echo "Available tags:"
    docker images "${REPO}" --format "{{.Tag}}"
    exit 1
fi

echo "📁 Create versioned release directory"
run_on_target "mkdir -p '${NEW_RELEASE_PATH}'"

echo "💾 Copy new files to server"
if [ -d "./server" ]; then
    retry scp -pr ./server/* "deploy:${NEW_RELEASE_PATH}/"
else
    echo "⚠️ No server directory found, error"
    exit 1
fi

echo "📝 Create new .env file with deployment configuration"
printf "%s" "${ENV_FILE_BASE64}" | base64 -d | run_on_target "cat > '${NEW_RELEASE_PATH}/.env' && chmod 600 '${NEW_RELEASE_PATH}/.env'"
# Add deployment color and image tag to .env
run_on_target "echo 'DEPLOYMENT_COLOR=${NEW_COLOR}' >> '${NEW_RELEASE_PATH}/.env'"
run_on_target "echo 'IMAGE_TAG=${IMAGE_TAG}' >> '${NEW_RELEASE_PATH}/.env'"

# Add domain name based on environment
if [ "${PROD}" = "true" ]; then
    DOMAIN_NAME="${PRODUCTION_DOMAIN:-pkmntrade.club}"
else
    DOMAIN_NAME="${STAGING_DOMAIN:-staging.pkmntrade.club}"
fi
# if there is a third part to the domain name, remove it
BASE_DOMAIN_NAME="${BASE_DOMAIN:-pkmntrade.club}"
run_on_target "echo 'DOMAIN_NAME=${DOMAIN_NAME}' >> '${NEW_RELEASE_PATH}/.env'"
run_on_target "echo 'BASE_DOMAIN_NAME=${BASE_DOMAIN_NAME}' >> '${NEW_RELEASE_PATH}/.env'"
run_on_target "echo 'REPLICA_COUNT=${REPLICA_COUNT}' >> '${NEW_RELEASE_PATH}/.env'"

echo "🔑 Set up certs"
run_on_target "mkdir -p '${NEW_RELEASE_PATH}/certs' && chmod 550 '${NEW_RELEASE_PATH}/certs' && chown 99:root '${NEW_RELEASE_PATH}/certs'"
printf "%s" "$CF_PEM_CERT" | run_on_target "cat > '${NEW_RELEASE_PATH}/certs/crt.pem' && chmod 440 '${NEW_RELEASE_PATH}/certs/crt.pem' && chown 99:root '${NEW_RELEASE_PATH}/certs/crt.pem'"
printf "%s" "$CF_PEM_CA" | run_on_target "cat > '${NEW_RELEASE_PATH}/certs/ca.pem' && chmod 440 '${NEW_RELEASE_PATH}/certs/ca.pem' && chown 99:root '${NEW_RELEASE_PATH}/certs/ca.pem'"

echo "📝 Save deployment metadata"
run_on_target "echo '${DEPLOYMENT_TIMESTAMP}' > '${NEW_RELEASE_PATH}/.deployment_version'"
run_on_target "echo '${PROD}' > '${NEW_RELEASE_PATH}/.deployment_is_prod'"
run_on_target "echo '${NEW_COLOR}' > '${NEW_RELEASE_PATH}/.deployment_color'"
run_on_target "echo '${IMAGE_TAG}' > '${NEW_RELEASE_PATH}/.image_tag'"
run_on_target "echo '${GIT_SHA:-unknown}' > '${NEW_RELEASE_PATH}/.git_sha'"

# Save previous version info for potential rollback
run_on_target "if [ -L '${CURRENT_LINK_PATH}' ]; then readlink -f '${CURRENT_LINK_PATH}' > '${NEW_RELEASE_PATH}/.previous_version'; fi"

# export PREVIOUS_RELEASE_PATH
if [ "$CURRENT_COLOR" != "none" ]; then
    PREVIOUS_RELEASE_PATH=$(run_on_target "cat ${NEW_RELEASE_PATH}/.previous_version")
else
    PREVIOUS_RELEASE_PATH=""
fi
run_on_target "export PREVIOUS_RELEASE_PATH='${PREVIOUS_RELEASE_PATH}'"

echo "🔗 Update current symlink to new release"
run_on_target "ln -sfn '${NEW_RELEASE_PATH}' '${CURRENT_LINK_PATH}'"

# Get deployment configuration
PROJECT_NAME=$(get_project_name "$NEW_COLOR")
COMPOSE_FILES=$(get_compose_files)
WEB_SERVICE=$(get_web_service_name)

# create network if it doesn't exist
echo "🔗 Creating network ${PROJECT_NAME}_network"
run_on_target "docker network create ${REPO_NAME_ONLY}_network >/dev/null 2>&1 || true"

# Handle core services
if [ "$CURRENT_COLOR" = "none" ]; then
    echo "🚀 Starting core services (first deployment)"
    retry run_on_target "cd '${CURRENT_LINK_PATH}' && docker compose -f docker-compose_core.yml -p ${CORE_PROJECT_NAME} up -d"
    sleep 10  # Give core services time to start
else
    echo "ℹ️ Core services already running, checking for changes..."
    PREVIOUS_SHA1=$(run_on_target "sha1sum '${PREVIOUS_RELEASE_PATH}/docker-compose_core.yml' | awk '{print \$1}'")
    NEW_SHA1=$(run_on_target "sha1sum '${NEW_RELEASE_PATH}/docker-compose_core.yml' | awk '{print \$1}'")
    echo "PREV_SHA1: ${PREVIOUS_SHA1}"
    echo " NEW_SHA1: ${NEW_SHA1}"
    if [ -n "$PREVIOUS_SHA1" ] && [ -n "$NEW_SHA1" ]; then
        if [ "$PREVIOUS_SHA1" != "$NEW_SHA1" ]; then
            echo "🚀 Core services have changed, restarting..."
            retry run_on_target "cd '${CURRENT_LINK_PATH}' && docker compose -f docker-compose_core.yml -p ${CORE_PROJECT_NAME} down"
            retry run_on_target "cd '${CURRENT_LINK_PATH}' && docker compose -f docker-compose_core.yml -p ${CORE_PROJECT_NAME} up -d"
        else
            echo "ℹ️ Core services have not changed, still restarting due to current folder change..."
            retry run_on_target "cd '${CURRENT_LINK_PATH}' && docker compose -f docker-compose_core.yml -p ${CORE_PROJECT_NAME} down"
            retry run_on_target "cd '${CURRENT_LINK_PATH}' && docker compose -f docker-compose_core.yml -p ${CORE_PROJECT_NAME} up -d"
        fi
    else
        echo "❌ Current or previous core services not found, exiting..."
        exit 1
    fi
fi

echo "🚀 Start new ${NEW_COLOR} containers with image ${IMAGE_TAG}"
retry run_on_target "cd '${CURRENT_LINK_PATH}' && DEPLOYMENT_COLOR=${NEW_COLOR} IMAGE_TAG=${IMAGE_TAG} docker compose $COMPOSE_FILES -p ${PROJECT_NAME} up -d"

# Wait for new containers to be healthy
if ! wait_for_healthy_containers "$PROJECT_NAME" "$WEB_SERVICE" "$REPLICA_COUNT"; then
    echo "❌ New containers failed health checks. Cancelling deployment..."
    run_on_target "cd '${CURRENT_LINK_PATH}' && docker compose $COMPOSE_FILES -p ${PROJECT_NAME} down"
    #echo "🔄 Rolling back deployment..."
    #TODO: implement rollback
    exit 1
fi

echo "✅ New ${NEW_COLOR} deployment is healthy"

# Refresh gatekeepers
refresh_gatekeepers

# Wait for traffic to stabilize
wait_with_countdown 20 "⏳ Waiting for traffic to stabilize..."

# Clean up old containers if this isn't the first deployment
if [ "$CURRENT_COLOR" != "none" ]; then
    # Get the old image tag before cleanup
    OLD_IMAGE_TAG=$(get_deployment_image_tag "$CURRENT_COLOR")
    echo "📷 Old deployment was using image: ${OLD_IMAGE_TAG}"
    
    cleanup_color_containers "$CURRENT_COLOR"
    echo "✅ Old containers removed"
fi

echo "🗑️  Clean up old releases (keep last 5)"
run_on_target "cd '${RELEASES_PATH}' && ls -dt */ 2>/dev/null | tail -n +6 | xargs -r rm -rf || true"

echo "✅ Blue-Green deployment completed"
echo "   Active color: ${NEW_COLOR}"
echo "   Image tag: ${IMAGE_TAG}"