# deploy.yml — Continuous Deployment to HuggingFace Spaces + Vercel
#
# ── What this file does ──────────────────────────────────────────────────────
#
# On every push to main (after CI passes), two jobs run in parallel:
#
#   deploy-backend   →  pushes the project directory to a HuggingFace Space,
#                        which rebuilds the Docker container automatically
#
#   deploy-frontend  →  runs `vercel --prod` to deploy the React app to
#                        Vercel's global CDN
#
# ── Why separate jobs? ───────────────────────────────────────────────────────
#
# Jobs run in parallel by default in GitHub Actions. Backend and frontend
# are independent — no reason to wait for one before starting the other.
# Total deploy time = max(backend_time, frontend_time), not the sum.
#
# ── Secrets vs Variables ─────────────────────────────────────────────────────
#
# GitHub Actions has two kinds of stored values:
#   secrets  → encrypted, never shown in logs (tokens, API keys)
#   vars     → plain text, visible in logs (usernames, IDs, config)
#
# Set these in: GitHub repo → Settings → Secrets and variables → Actions
#
#   Secrets required:
#     HF_TOKEN           HuggingFace token with "write" permission to your Space
#     VERCEL_TOKEN       Vercel personal access token
#     VERCEL_ORG_ID      From `vercel whoami` or project settings
#     VERCEL_PROJECT_ID  From `vercel project ls` or .vercel/project.json
#
#   Variables required:
#     HF_USERNAME        Your HuggingFace username (e.g. "umang")
#     HF_SPACE_NAME      Your HF Space name (e.g. "github-rag-copilot")
#
# ── One-time setup (before this workflow will work) ──────────────────────────
#
# 1. Create HF Space at https://huggingface.co/new-space
#    - SDK: Docker
#    - Visibility: Public (free hardware requires public spaces)
#    - Hardware: CPU basic (free)
#    - Set env vars in Space Settings → Variables (never commit secrets):
#        QDRANT_URL, QDRANT_API_KEY, QDRANT_COLLECTION,
#        GROQ_API_KEY, GEMINI_API_KEY, NOMIC_API_KEY,
#        FRONTEND_URL (your Vercel URL)
#
# 2. Create Vercel project at https://vercel.com/new
#    - Root directory: cartographer/ui
#    - Build command: npm run build
#    - Output dir: dist
#    - Set env var: VITE_API_URL = https://<hf-username>-<hf-space-name>.hf.space
#    - Get IDs: `npx vercel whoami` and `npx vercel project ls`
#
# 3. Add the secrets/variables above to this GitHub repo

name: Deploy

on:
  push:
    branches: [main]

# Only run deploy after CI passes — ensures broken code is never deployed
# This references the workflow named "CI" in ci.yml
# Remove this if you want deploys to run independently of CI
concurrency:
  group: deploy-${{ github.ref }}
  cancel-in-progress: true  # if a new push arrives, cancel the in-flight deploy

jobs:

  # ── Backend → HuggingFace Spaces ─────────────────────────────────────────
  #
  # HuggingFace Spaces is a git-based hosting platform. Every Space has a git
  # repository at https://huggingface.co/spaces/{user}/{space}. When you push
  # new code there, HF automatically:
  #   1. Detects the Dockerfile in the repo root
  #   2. Builds a Docker image from it
  #   3. Runs the container (your FastAPI app) on port 7860
  #
  # The challenge: our Dockerfile lives inside a subdirectory (cartographer/)
  # of a larger monorepo. HF Spaces expects the Dockerfile at the repo root.
  #
  # Solution: `git subtree split`
  #   This Git command creates a new synthetic branch where the specified
  #   prefix directory becomes the root. The full history is preserved but
  #   rewritten so every commit only contains files from that directory.
  #   We push this synthetic branch as `main` to HF Spaces.
  #
  deploy-backend:
    name: Backend → HuggingFace Spaces
    runs-on: ubuntu-latest

    steps:
      - name: Checkout repository
        uses: actions/checkout@v4
        with:
          # fetch-depth: 0 means fetch the FULL git history, not just the latest commit.
          # git subtree split needs to walk history to build the synthetic branch —
          # with a shallow clone (fetch-depth: 1, the default) it would fail.
          fetch-depth: 0

      - name: Configure git identity
        # Git requires a name + email to create commits. GitHub Actions runner
        # has no global git config, so we set it here. These values are
        # arbitrary — they appear in the HF Space's git log.
        run: |
          git config --global user.email "github-actions[bot]@users.noreply.github.com"
          git config --global user.name "github-actions[bot]"

      - name: Push to HuggingFace Space
        # The GitHub repo root IS the project root (Dockerfile is at root),
        # so we push main directly to HF Spaces — no subtree split needed.
        # --force is safe here: the HF Space is a deployment target only,
        # nobody commits to it directly.
        env:
          HF_TOKEN: ${{ secrets.HF_TOKEN }}
          HF_USERNAME: ${{ vars.HF_USERNAME }}
          HF_SPACE_NAME: ${{ vars.HF_SPACE_NAME }}
        run: |
          git push \
            "https://$HF_USERNAME:$HF_TOKEN@huggingface.co/spaces/$HF_USERNAME/$HF_SPACE_NAME" \
            main:main \
            --force

  # ── Frontend → Vercel ──────────────────────────────────────────────────────
  #
  # Vercel hosts static sites. The React app is built with `npm run build`
  # which produces a `dist/` directory. Vercel uploads this to their global
  # CDN (100+ edge nodes) so users get the assets from the nearest location.
  #
  # `vercel --prod` is the CLI command that:
  #   1. Runs the build command configured in the Vercel project
  #   2. Uploads the output to Vercel's CDN
  #   3. Promotes the deployment to the production URL
  #
  # Authentication: Vercel uses a token + org ID + project ID triple.
  # These come from your Vercel dashboard (see setup instructions above).
  #
  deploy-frontend:
    name: Frontend → Vercel
    runs-on: ubuntu-latest

    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Set up Node
        uses: actions/setup-node@v4
        with:
          node-version: "20"
          cache: npm
          cache-dependency-path: ui/package-lock.json

      - name: Install dependencies
        working-directory: ui
        run: npm ci
        # `npm ci` (clean install) is preferred over `npm install` in CI:
        # - Installs exactly the versions in package-lock.json (reproducible)
        # - Fails if package-lock.json is out of sync with package.json
        # - Deletes node_modules before installing (clean state)

      - name: Deploy to Vercel
        # We pass VITE_API_URL so the React app knows where the backend lives.
        # This env var is baked into the JS bundle at build time by Vite —
        # it becomes a literal string in the compiled output (not a runtime env var).
        # Run from repo root — Vercel project already has root dir set to "ui",
        # so running from ui/ would make Vercel look for "ui/ui" (double-nested).
        env:
          VERCEL_TOKEN: ${{ secrets.VERCEL_TOKEN }}
          VERCEL_ORG_ID: ${{ secrets.VERCEL_ORG_ID }}
          VERCEL_PROJECT_ID: ${{ secrets.VERCEL_PROJECT_ID }}
          # Set this after you know your HF Space URL.
          # Format: https://<hf-username>-<hf-space-name>.hf.space
          # (HF converts "my-name/my-space" → "my-name-my-space.hf.space")
          VITE_API_URL: ${{ vars.HF_SPACE_URL }}
        run: |
          npx vercel --prod \
            --token="$VERCEL_TOKEN" \
            --yes
          # --yes skips interactive confirmation prompts