#!/bin/bash
set -euo pipefail

# Rollback deployment by swapping colors
# Usage: ./rollback-deployment.sh

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

validate_deployment_env

# Get current state
STATE=$(get_deployment_state)

echo "🔍 Current deployment state: $STATE"

if [ "$STATE" = "none" ]; then
    echo "❌ No active deployment found to rollback"
    exit 1
fi

if [ "$STATE" != "both" ]; then
    echo "❌ Rollback requires both colors to be running"
    echo "   Current state: only $STATE is running"
    echo ""
    echo "   To perform a manual rollback:"
    echo "   1. Find the previous release in ${RELEASES_PATH}/"
    echo "   2. Update the symlink: ln -sfn <previous-release> ${CURRENT_LINK_PATH}"
    echo "   3. Redeploy using: ./deploy-blue-green.sh"
    exit 1
fi

# Both colors running - determine which is newer
CURRENT_COLOR=$(get_current_color)
ROLLBACK_COLOR=$(switch_color "$CURRENT_COLOR")

# Get image tags for both deployments
CURRENT_IMAGE=$(get_deployment_image_tag "$CURRENT_COLOR")
ROLLBACK_IMAGE=$(get_deployment_image_tag "$ROLLBACK_COLOR")

echo "🔄 Rolling back from $CURRENT_COLOR (newer) to $ROLLBACK_COLOR (older)"
echo "   Current image: ${CURRENT_IMAGE}"
echo "   Rollback image: ${ROLLBACK_IMAGE}"

# Verify the rollback image exists
if ! run_on_target "docker images -q 'badbl0cks/pkmntrade-club:${ROLLBACK_IMAGE}' | grep -q ."; then
    echo "❌ Rollback image not found: badbl0cks/pkmntrade-club:${ROLLBACK_IMAGE}"
    echo "   The image may have been pruned. Cannot perform rollback."
    exit 1
fi

# Verify rollback color is healthy
ROLLBACK_PROJECT=$(get_project_name "$ROLLBACK_COLOR")
HEALTHY_COUNT=$(count_containers "label=com.docker.compose.project=${ROLLBACK_PROJECT} --filter status=running")

if [ "$HEALTHY_COUNT" -eq 0 ]; then
    echo "❌ No healthy $ROLLBACK_COLOR containers found, cannot perform rollback"
    exit 1
fi

echo "✅ Found $HEALTHY_COUNT healthy $ROLLBACK_COLOR containers"

# Store the release path of the current color before we change the symlink
CURRENT_RELEASE_PATH=$(readlink -f "${CURRENT_LINK_PATH}")

echo "🔄 Performing rollback..."

echo "🔎 Finding release for rollback color ($ROLLBACK_COLOR)..."
# Find the second newest release directory. This is assumed to be the rollback target.
ROLLBACK_RELEASE_PATH=$(ls -dt "${RELEASES_PATH}"/*/ | sed -n '2p' | tr -d '\n')

if [ -z "$ROLLBACK_RELEASE_PATH" ]; then
    echo "❌ Could not find a previous release to rollback to in ${RELEASES_PATH}"
    exit 1
fi
echo "   Found rollback release: ${ROLLBACK_RELEASE_PATH}"

echo "🔗 Switching 'current' symlink to point to rollback release..."
ln -sfn "${ROLLBACK_RELEASE_PATH}" "${CURRENT_LINK_PATH}"

# Refresh gatekeepers to switch traffic to the rollback color
refresh_gatekeepers

wait_with_countdown 10 "⏳ Waiting for traffic to stabilize on $ROLLBACK_COLOR..."

# Stop and clean up current color containers, using the correct release path
export CLEANUP_RELEASE_PATH="${CURRENT_RELEASE_PATH}"
cleanup_color_containers "$CURRENT_COLOR"
unset CLEANUP_RELEASE_PATH

# Refresh gatekeepers again to remove routes to the old color
refresh_gatekeepers

echo "✅ Rollback completed!"
echo "   Active deployment: $ROLLBACK_COLOR"
echo ""
echo "📌 Note: The next deployment will now deploy as $CURRENT_COLOR"