#!/usr/bin/env bash
# Fetches the previous AI review comment from the PR (if any).
# Required env vars: GITEA_TOKEN, GITEA_SERVER_URL, REPO, PR_NUMBER
# Writes to $GITHUB_OUTPUT: prev_sha, prev_review
set -euo pipefail

COMMENTS=$(curl -sf \
  -H "Authorization: token ${GITEA_TOKEN}" \
  -H "Content-Type: application/json" \
  "${GITEA_SERVER_URL}/api/v1/repos/${REPO}/issues/${PR_NUMBER}/comments")

# Find the most recent comment that contains our SHA marker
PREV_COMMENT=$(echo "$COMMENTS" | jq -r '
  [ .[] | select(.body | contains("<!-- ai-review-sha:")) ] | last | .body // ""
')

if [ -z "$PREV_COMMENT" ]; then
  echo "No previous AI review found — will run a full review."
  echo "prev_sha=" >> "$GITHUB_OUTPUT"
  echo "prev_review=" >> "$GITHUB_OUTPUT"
  exit 0
fi

PREV_SHA=$(echo "$PREV_COMMENT" | grep -oP '(?<=<!-- ai-review-sha:)[^>]+(?= -->)' || true)
# Strip the trailing marker line to get just the review body
PREV_REVIEW=$(echo "$PREV_COMMENT" | sed '/<!-- ai-review-sha:/d')

echo "Found previous review at commit ${PREV_SHA}"

echo "prev_sha=${PREV_SHA}" >> "$GITHUB_OUTPUT"

echo "prev_review<<EOF" >> "$GITHUB_OUTPUT"
echo "$PREV_REVIEW" >> "$GITHUB_OUTPUT"
echo "EOF" >> "$GITHUB_OUTPUT"