name: "Notify Discord when a PR is opened or merged"

on:
  workflow_call:
    inputs:
      PR_TITLE:
        description: "The title of the PR"
        type: string
      PR_URL:
        description: "The URL of the PR"
        type: string
      PR_AUTHOR:
        description: "The author of the PR"
        type: string
      PR_STATUS:
        description: "The status of the PR"
        type: string
      DISCORD_CHANNEL_ID:
        description: "The Discord channel ID"
        type: string
      PR_NUMBER:
        description: "The number of the PR"
        type: string
      DISCORD_GUILD_ID:
        description: "The Discord guild ID"
        type: string
    secrets:
      DISCORD_WEBHOOK_URL:
        description: "Discord Webhook URL"
      DISCORD_BOT_TOKEN:
        description: "Discord Bot Token"

jobs:
  open_thread:
    runs-on: ubicloud-standard-2
    if: ${{ inputs.PR_STATUS == 'opened' }}
    steps:
      - name: Send Discord notification and start a thread
        env:
          WEBHOOK_URL: ${{ secrets.DISCORD_WEBHOOK_URL }}
          PR_TITLE: ${{ inputs.PR_TITLE }}
          PR_NUMBER: ${{ inputs.PR_NUMBER }}
          PR_URL: ${{ inputs.PR_URL }}
          PR_AUTHOR: ${{ inputs.PR_AUTHOR }}
        run: |
          payload=$(jq -n \
            --arg content "${PR_URL}" \
            --arg thread "#${PR_NUMBER}: $PR_TITLE by \`${PR_AUTHOR}\`" \
            '{
              content: $content,
              thread_name: $thread,
              auto_archive_duration: 10080
            }'
          )
          curl -H "Content-Type: application/json" \
            -X POST \
            -d "$payload" \
            "$WEBHOOK_URL"

  merge_success_emoji:
    runs-on: ubuntu-latest
    if: ${{ inputs.PR_STATUS == 'merged' }}
    steps:
      - name: React
        env:
          BOT_TOKEN: ${{ secrets.DISCORD_BOT_TOKEN }}
          CHANNEL_ID: ${{ inputs.DISCORD_CHANNEL_ID }}
          GUILD_ID: ${{ inputs.DISCORD_GUILD_ID }}
          PR_NUMBER: ${{ inputs.PR_NUMBER }}
        run: |
          # 1) get PR thread
          threads=$(curl -H "Authorization: Bot $BOT_TOKEN" "https://discord.com/api/v10/guilds/${GUILD_ID}/threads/active")
          thread_id=$(
            echo "$threads" \
              | jq -r --arg cid "$CHANNEL_ID" \
                    --arg pref "#${PR_NUMBER}:" \
                '.threads[]
                | select(.parent_id == $cid and (.name | startswith($pref)))
                | .id'
          )
          if [ -z "$thread_id" ]; then
            echo "Thread not found"
            exit 1
          fi
          # 2) get the first message in that thread
          messages=$(curl -H "Authorization: Bot $BOT_TOKEN" \
            "https://discord.com/api/v10/channels/$thread_id/messages?limit=1")
          message_id=$(echo "$messages" | jq -r '.[-1].id')

          if [ -z "$message_id" ]; then
            echo "Message not found"
            exit 1
          fi

          # 3) add the ✅ reaction
          curl -X PUT \
            -H "Authorization: Bot $BOT_TOKEN" \
            "https://discord.com/api/v10/channels/$thread_id/messages/$message_id/reactions/%E2%9C%85/@me"