#!/bin/bash
# Gravl deployment script
# Prevents stale containers by always building fresh with --no-cache
# 
# Usage:
#   ./scripts/deploy.sh
#
# What it does:
#   1. Pulls latest code from git
#   2. Captures build metadata (commit SHA, timestamp)
#   3. Builds fresh Docker images with --no-cache (no layer caching)
#   4. Restarts containers to use new images
#   5. Polls /api/health endpoint until backend is ready
#   6. Logs all steps to logs/deploy.log
#
# Rationale for --no-cache:
#   Docker caching can hide stale assets (JS, CSS, images) when source files change.
#   Using --no-cache ensures all layers rebuild fresh, guaranteeing new code is deployed.
#   Trade-off: Slightly slower builds (30-60s vs 10-20s with cache), but safer.
#
# See: /docs/DEPLOYMENT.md for troubleshooting

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
REPO_DIR="$(dirname "$SCRIPT_DIR")"
LOG_FILE="$REPO_DIR/logs/deploy.log"
BACKEND_HEALTH="http://localhost:3001/api/health"

log() {
  echo "[$(date '+%Y-%m-%d %H:%M:%S')] $*" | tee -a "$LOG_FILE"
}

mkdir -p "$REPO_DIR/logs"
cd "$REPO_DIR"

log "=== Deploy started ==="

# Pull latest code from remote
# Fails if there are local changes or merge conflicts
log "Pulling latest code..."
git pull

# Capture build metadata to embed in Docker image labels
# These labels allow build-check.sh to verify deployed containers match local code
GIT_COMMIT=$(git rev-parse HEAD)
BUILD_DATE=$(date -u +"%Y-%m-%dT%H:%M:%SZ")
log "Commit: $(git rev-parse --short HEAD) | Date: $BUILD_DATE"

# Build fresh images — no-cache prevents Docker layer caching
# This is critical for frontend deployments where CSS/JS changes might not be obvious
# to Docker's layer detection algorithm
log "Building images (--no-cache)..."
export GIT_COMMIT BUILD_DATE
docker compose build --no-cache

# Restart containers with new images
# --force-recreate stops old containers and removes them before starting new ones
log "Starting containers..."
docker compose up -d --force-recreate

# Health check: poll /api/health endpoint until it responds with 200 OK
# Timeout: 60 seconds (12 retries × 5 seconds each)
# This prevents deployment from completing if the backend is broken
log "Health check..."
for i in $(seq 1 12); do
  if curl -sf "$BACKEND_HEALTH" >/dev/null 2>&1; then
    log "Backend healthy"
    break
  fi
  [ "$i" -eq 12 ] && { log "ERROR: Health check failed after 60s"; exit 1; }
  log "Waiting... ($i/12)"
  sleep 5
done

log "=== Deploy complete: ${GIT_COMMIT:0:7} ==="