ai-review.yml

name: AI Code Review

on:
  pull_request:
    types: [opened, synchronize]
  workflow_dispatch:
    inputs:
      ai_provider:
        description: 'Primary AI provider for this run'
        required: false
        default: 'claude'
        type: choice
        options:
          - claude
          - openai

jobs:
  review:
    runs-on: ubuntu-latest
    permissions:
      pull-requests: write
    # Priority: manual dispatch input > repo variable (vars.AI_PROVIDER) > default 'claude'
    env:
      AI_PROVIDER: ${{ github.event_name == 'workflow_dispatch' && inputs.ai_provider || vars.AI_PROVIDER || 'claude' }}

    steps:
      - name: Checkout repo
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Get PR diff
        run: |
          BASE_REF="${{ github.base_ref || 'main' }}"
          git fetch origin "$BASE_REF"
          git diff "origin/$BASE_REF" > diff.txt

      - name: Build prompt
        env:
          PR_BODY: ${{ github.event.pull_request.body }}
        run: |
          printf '%s\n' "$PR_BODY" > pr_body.txt
          python3 -c "
          template = open('.github/prompt-template.txt').read()
          rules    = open('.github/review-guidelines.md').read()
          pr_body  = open('pr_body.txt').read()
          diff     = open('diff.txt').read()
          open('prompt.txt', 'w').write(template.format(rules=rules, pr_body=pr_body, diff=diff))
          "

      # Tries the configured primary provider. continue-on-error allows the
      # fallback step to run if this fails (bad key, quota, outage, etc.)
      - name: Call primary provider
        id: primary
        continue-on-error: true
        env:
          ANTHROPIC_API_KEY: ${{ secrets.ANTHROPIC_API_KEY }}
          OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}
        run: |
          if [ "$AI_PROVIDER" = "claude" ]; then
            PAYLOAD=$(jq -n --rawfile prompt prompt.txt \
              '{model:"claude-sonnet-4-6",max_tokens:1024,messages:[{role:"user",content:$prompt}]}')
            RESPONSE=$(curl -sf https://api.anthropic.com/v1/messages \
              -H "x-api-key: $ANTHROPIC_API_KEY" \
              -H "anthropic-version: 2023-06-01" \
              -H "Content-Type: application/json" \
              -d "$PAYLOAD")
            REVIEW=$(echo "$RESPONSE" | jq -re '.content[0].text')
            USED="Claude Sonnet 4.6 (Anthropic)"
          else
            PAYLOAD=$(jq -n --rawfile prompt prompt.txt \
              '{model:"gpt-4o-mini",temperature:0.3,messages:[{role:"user",content:$prompt}]}')
            RESPONSE=$(curl -sf https://api.openai.com/v1/chat/completions \
              -H "Authorization: Bearer $OPENAI_API_KEY" \
              -H "Content-Type: application/json" \
              -d "$PAYLOAD")
            REVIEW=$(echo "$RESPONSE" | jq -re '.choices[0].message.content')
            USED="GPT-4o-mini (OpenAI)"
          fi
          echo "REVIEW<<EOF" >> "$GITHUB_OUTPUT"
          printf '%s\n' "$REVIEW" >> "$GITHUB_OUTPUT"
          echo "EOF" >> "$GITHUB_OUTPUT"
          echo "USED=$USED" >> "$GITHUB_OUTPUT"

      # Only runs if the primary provider failed — automatically uses the other provider.
      - name: Call fallback provider
        id: fallback
        if: steps.primary.outcome == 'failure'
        env:
          ANTHROPIC_API_KEY: ${{ secrets.ANTHROPIC_API_KEY }}
          OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}
        run: |
          echo "::warning::Primary provider ($AI_PROVIDER) failed — switching to fallback."
          if [ "$AI_PROVIDER" = "claude" ]; then
            PAYLOAD=$(jq -n --rawfile prompt prompt.txt \
              '{model:"gpt-4o-mini",temperature:0.3,messages:[{role:"user",content:$prompt}]}')
            RESPONSE=$(curl -sf https://api.openai.com/v1/chat/completions \
              -H "Authorization: Bearer $OPENAI_API_KEY" \
              -H "Content-Type: application/json" \
              -d "$PAYLOAD") || { echo "::error::Both Claude and OpenAI failed."; exit 1; }
            REVIEW=$(echo "$RESPONSE" | jq -r '.choices[0].message.content // ("OpenAI error: " + (.error.message // "unknown"))')
            USED="GPT-4o-mini (OpenAI) ⚠️ fallback from Claude"
          else
            PAYLOAD=$(jq -n --rawfile prompt prompt.txt \
              '{model:"claude-sonnet-4-6",max_tokens:1024,messages:[{role:"user",content:$prompt}]}')
            RESPONSE=$(curl -sf https://api.anthropic.com/v1/messages \
              -H "x-api-key: $ANTHROPIC_API_KEY" \
              -H "anthropic-version: 2023-06-01" \
              -H "Content-Type: application/json" \
              -d "$PAYLOAD") || { echo "::error::Both OpenAI and Claude failed."; exit 1; }
            REVIEW=$(echo "$RESPONSE" | jq -r '.content[0].text // ("Claude error: " + (.error.message // "unknown"))')
            USED="Claude Sonnet 4.6 (Anthropic) ⚠️ fallback from OpenAI"
          fi
          echo "REVIEW<<EOF" >> "$GITHUB_OUTPUT"
          printf '%s\n' "$REVIEW" >> "$GITHUB_OUTPUT"
          echo "EOF" >> "$GITHUB_OUTPUT"
          echo "USED=$USED" >> "$GITHUB_OUTPUT"

      - name: Post review comment
        if: github.event_name == 'pull_request'
        uses: actions/github-script@v7
        env:
          PRIMARY_REVIEW: ${{ steps.primary.outputs.REVIEW }}
          PRIMARY_USED: ${{ steps.primary.outputs.USED }}
          FALLBACK_REVIEW: ${{ steps.fallback.outputs.REVIEW }}
          FALLBACK_USED: ${{ steps.fallback.outputs.USED }}
        with:
          script: |
            const review = process.env.PRIMARY_REVIEW  || process.env.FALLBACK_REVIEW;
            const label  = process.env.PRIMARY_USED    || process.env.FALLBACK_USED;
            await github.rest.issues.createComment({
              issue_number: context.issue.number,
              owner: context.repo.owner,
              repo: context.repo.repo,
              body: `## 🤖 AI Code Review — ${label}\n\n${review}`
            });

      - name: Print review (manual run)
        if: github.event_name == 'workflow_dispatch'
        env:
          PRIMARY_REVIEW: ${{ steps.primary.outputs.REVIEW }}
          PRIMARY_USED: ${{ steps.primary.outputs.USED }}
          FALLBACK_REVIEW: ${{ steps.fallback.outputs.REVIEW }}
          FALLBACK_USED: ${{ steps.fallback.outputs.USED }}
        run: |
          LABEL="${PRIMARY_USED:-$FALLBACK_USED}"
          REVIEW="${PRIMARY_REVIEW:-$FALLBACK_REVIEW}"
          echo "=== AI Review — $LABEL ==="
          printf '%s\n' "$REVIEW"