#!/bin/sh
# Oikos rollback — redeploys previous SHA tag and restores DB from pre-deploy dump.
# Usage: ./scripts/rollback.sh <previous-sha>
# Phase 6 acceptance: rehearsed once before going live.

set -e

PREVIOUS_SHA="${1:-}"
if [ -z "$PREVIOUS_SHA" ]; then
    echo "usage: $0 <previous-sha>"
    echo "  e.g. $0 abc1234"
    exit 1
fi

PROFILE="${PROFILE:-full}"
DUMP_DIR="${DUMP_DIR:-/opt/oikos/backups}"
HEALTH_URL="${HEALTH_URL:-http://localhost:8090/healthz}"
REPO_DIR="${REPO_DIR:-$PWD}"

cd "$REPO_DIR"

echo "=== OIKOS ROLLBACK to $PREVIOUS_SHA ==="
echo ""

# 1. Stop services
echo "[1/4] stopping services"
docker compose --profile "$PROFILE" down

# 2. Restore DB from pre-deploy dump
echo "[2/4] restoring database"
DUMP_FILE="$DUMP_DIR/pre-deploy-$(echo $PREVIOUS_SHA | cut -c1-7).sql"
if [ -f "$DUMP_FILE" ]; then
    docker compose --profile "$PROFILE" up -d postgres
    sleep 5
    docker compose exec -T postgres psql -U oikos -d oikos < "$DUMP_FILE"
    echo "DB restored from $DUMP_FILE"
else
    echo "WARNING: no dump found at $DUMP_FILE — proceeding with current DB"
fi

# 3. Checkout previous SHA
echo "[3/4] checking out $PREVIOUS_SHA"
git checkout "$PREVIOUS_SHA"

# 4. Rebuild and restart
echo "[4/4] rebuild and restart"
DOCKER_BUILDKIT=1 docker compose --profile "$PROFILE" build
docker compose --profile "$PROFILE" up -d

# Health check
for i in $(seq 1 30); do
    if curl -sf "$HEALTH_URL" > /dev/null 2>&1; then
        echo "rollback healthy after ${i}s"
        # Return to main branch (but keep the old deployment)
        git checkout main 2>/dev/null || true
        echo "=== ROLLBACK COMPLETE — RUNNING ON $PREVIOUS_SHA ==="
        exit 0
    fi
    sleep 2
done

echo "ERROR: rollback health check failed"
exit 1