#!/usr/bin/env bash
set -euo pipefail

# === Inputs via ENV ===================================================
COMMENTER_TYPE="${COMMENTER_TYPE:-}"
COMMENTER_INPUT="${COMMENTER_INPUT:-}"
COMMENTER_EXITCODE="${COMMENTER_EXITCODE:-0}"
WORKING_DIR="${WORKING_DIR:-}"

PR_COMMENTS_URL="${PR_COMMENTS_URL:-}"
PR_COMMENT_ID="${PR_COMMENT_ID:-}"
PR_COMMENT_URI="${PR_COMMENT_URI:-}"
GITHUB_TOKEN="${GITHUB_TOKEN:-}"

# === Validate inputs =================================================
if [[ -z "$COMMENTER_TYPE" ]]; then
  echo "❌ commenter_type is required."
  exit 1
fi

if [[ -z "$GITHUB_TOKEN" ]]; then
  echo "❌ GITHUB_TOKEN is required to post PR comments."
  exit 1
fi

# === Move into working directory if specified ========================
if [[ -n "$WORKING_DIR" ]]; then
  TARGET_DIR="${GITHUB_WORKSPACE}/${WORKING_DIR}"
  if [[ ! -d "$TARGET_DIR" ]]; then
    echo "❌ Error: Cannot change to working directory '${WORKING_DIR}'"
    exit 1
  fi
  echo "🔹 Changing to working directory: $WORKING_DIR"
  cd "$TARGET_DIR"
else
  cd "${GITHUB_WORKSPACE:-.}"
fi

echo "📁 Current working directory: $(pwd)"
echo "📦 Repository root: ${GITHUB_WORKSPACE:-N/A}"

# === Detect IaC command ==============================================
if command -v tofu &>/dev/null; then
  TOFU_CMD="tofu"
elif command -v terraform &>/dev/null; then
  TOFU_CMD="terraform"
else
  echo "❌ Neither 'tofu' nor 'terraform' found in PATH."
  echo "PATH: $PATH"
  exit 1
fi

echo "🧰 Using IaC command: $TOFU_CMD ($(command -v $TOFU_CMD))"

# === Prepare comment body ===========================================
EXIT_STATUS_MSG=""
if [[ "$COMMENTER_EXITCODE" =~ ^[0-9]+$ && "$COMMENTER_EXITCODE" -eq 0 ]]; then
  EXIT_STATUS_MSG="✅ ${COMMENTER_TYPE^} succeeded."
else
  EXIT_STATUS_MSG="❌ ${COMMENTER_TYPE^} failed with exit code ${COMMENTER_EXITCODE}."
fi

COMMENT_BODY="### ${COMMENTER_TYPE^} Results
\`\`\`
${COMMENTER_INPUT}
\`\`\`
${EXIT_STATUS_MSG}
"

# === Determine PR_COMMENTS_URL if missing ===========================
if [[ -z "$PR_COMMENTS_URL" ]]; then
  echo "⚠️ PR_COMMENTS_URL not provided, attempting to generate..."

  if [[ -n "$GITEA_API_URL" && -n "$GITEA_REPOSITORY" && -n "$GITEA_PULL_REQUEST_ID" ]]; then
    PR_COMMENTS_URL="${GITEA_API_URL}/repos/${GITEA_REPOSITORY}/issues/${GITEA_PULL_REQUEST_ID}/comments"
    PR_COMMENT_URI="${GITEA_API_URL}/repos/${GITEA_REPOSITORY}/issues/comments"
    echo "✅ Generated Gitea PR_COMMENTS_URL: $PR_COMMENTS_URL"

  elif [[ -n "$GITHUB_EVENT_PATH" && -f "$GITHUB_EVENT_PATH" ]]; then
    PR_NUMBER=$(jq -r ".pull_request.number" "$GITHUB_EVENT_PATH")
    if [[ "$PR_NUMBER" != "null" ]]; then
      PR_COMMENTS_URL=$(jq -r ".pull_request.comments_url" "$GITHUB_EVENT_PATH")
      PR_COMMENT_URI=$(jq -r ".repository.issue_comment_url" "$GITHUB_EVENT_PATH" | sed "s|{/number}||g")
      echo "✅ Generated GitHub PR_COMMENTS_URL: $PR_COMMENTS_URL"
    else
      echo "❌ Not a pull request. Cannot generate PR_COMMENTS_URL."
      exit 0
    fi

  else
    echo "❌ Cannot determine PR_COMMENTS_URL automatically. Please provide it as input."
    exit 1
  fi
fi

# === Post Comment ====================================================
if [[ -n "$PR_COMMENT_ID" && -n "$PR_COMMENT_URI" ]]; then
  echo "🌀 Updating existing comment (ID: ${PR_COMMENT_ID})"
  curl -sS -X PATCH \
    -H "Authorization: token ${GITHUB_TOKEN}" \
    -H "Content-Type: application/json" \
    -d "$(jq -n --arg body "$COMMENT_BODY" '{body: $body}')" \
    "${PR_COMMENT_URI}" \
    || echo "⚠️ Failed to update existing comment."
else
  echo "🆕 Creating a new PR comment"
  curl -sS -X POST \
    -H "Authorization: token ${GITHUB_TOKEN}" \
    -H "Content-Type: application/json" \
    -d "$(jq -n --arg body "$COMMENT_BODY" '{body: $body}')" \
    "${PR_COMMENTS_URL}" \
    || echo "⚠️ Failed to create PR comment."
fi

echo "✅ Comment posted successfully."