#!/usr/bin/env bash
# Poll Gitea for new commits on main and deploy the docs site when it moves.
#
# Why polling: the agent host's cloud firewall only admits inbound SSH, so a
# Gitea webhook cannot reach the receiver (publishing/webhook-receiver.py) —
# every port is silently dropped. Outbound to git.inference.coop works, so the
# agent host polls instead: a push to main is picked up within ~a minute and
# deployed with no human action. When the operator opens a TCP port to the
# agent host in the Infomaniak panel, the webhook takes over (its unit is
# already installed); until then this watcher is the automation.
#
# Runs on the agent host as a systemd service (docs-deploy-poll.service).
# Deploy steps are serialised with the same lock the webhook receiver uses, so
# the two mechanisms can never deploy concurrently.

set -uo pipefail

REPO_DIR="${DOCS_REPO_DIR:-/home/ubuntu/repos/docs}"
ENV_FILE="${DOCS_ENV_FILE:-/home/ubuntu/.hermes/.env}"
LOG_FILE="${DOCS_DEPLOY_LOG:-/home/ubuntu/docs-deploy.log}"
LOCK_FILE="${DOCS_DEPLOY_LOCK:-/home/ubuntu/.docs-deploy.lock}"
STATE_FILE="${DOCS_DEPLOY_STATE:-/home/ubuntu/.docs-deploy.state}"
INTERVAL="${DOCS_POLL_INTERVAL:-60}"

cd "$REPO_DIR"

log() { echo "$(date -u +%Y-%m-%dT%H:%M:%SZ) [poll] $*" | tee -a "$LOG_FILE" >&2; }

# The Cloudron token travels by environment only; it is read from the env file
# and never echoed.
CLOUDRON_TOKEN="$(sed -n 's/^CLOUDRON_TOKEN=//p' "$ENV_FILE" | head -1 | tr -d '"' | tr -d "'")"
export CLOUDRON_TOKEN
if [ -z "$CLOUDRON_TOKEN" ]; then
  log "FATAL: CLOUDRON_TOKEN not found in $ENV_FILE"
  exit 1
fi

log "watcher started: polling $REPO_DIR every ${INTERVAL}s"

while true; do
  if ! git fetch --quiet origin main 2>>"$LOG_FILE"; then
    log "git fetch failed; will retry"
    sleep "$INTERVAL"
    continue
  fi

  REMOTE="$(git rev-parse origin/main 2>/dev/null || echo none)"
  # Compare against the commit last DEPLOYED (not the clone's HEAD): a push
  # made from this very clone would otherwise look like "no change".
  LAST_DEPLOYED="$(cat "$STATE_FILE" 2>/dev/null || echo none)"

  if [ "$LAST_DEPLOYED" != "$REMOTE" ]; then
    log "main moved: ${LAST_DEPLOYED:0:12} -> ${REMOTE:0:12}; deploying"
    # flock -n shares the receiver's lock: one deploy at a time, ever.
    if flock -n "$LOCK_FILE" bash -c '
      set -e
      cd "$1"
      git pull --ff-only origin main
      bash publishing/build.sh
      bash publishing/deploy.sh
    ' _ "$REPO_DIR" >>"$LOG_FILE" 2>&1; then
      printf '%s\n' "$REMOTE" > "$STATE_FILE"
      log "deploy finished for ${REMOTE:0:12}"
    else
      log "deploy FAILED for ${REMOTE:0:12} (see log above)"
    fi
  fi

  sleep "$INTERVAL"
done