# SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
# SPDX-License-Identifier: Apache-2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# Consolidated Fern Documentation Workflow
#
# This workflow handles all Fern documentation automation:
#
# 1. LINT (PRs): Validates Fern configuration and checks for broken links
#    - Triggers on PRs when docs/** files change
#    - Runs `fern check` and `fern docs broken-links`
#
# 2. SYNC & PUBLISH/PREVIEW: Syncs docs/ from source branch to fern/ on docs-website
#    - Triggers on push to main or PRs when docs/** files change
#    - On main: commits and pushes to docs-website, then publishes via `fern generate --docs`
#    - On PRs: generates a preview URL via `fern generate --docs --preview` and comments on PR
#    - Preserves versioned documentation (products[0]) from docs-website's docs.yml
#
# 3. VERSION RELEASE (tags): Creates versioned documentation snapshot
#    - Triggers on new version tags (vX.Y.Z format)
#    - Creates fern/pages-vX.Y.Z/ directory on docs-website branch
#    - Updates fern/docs.yml with new version entry
#    - Publishes docs to Fern after releasing
#
# Note: The publish step is included inline because pushes made with GITHUB_TOKEN
# do not trigger other workflows (GitHub's anti-recursion guard), so we cannot
# rely on a separate publish-fern-docs.yml workflow for bot-initiated pushes.

name: Fern Docs

on:
  push:
    branches:
      - main
      - "pull-request/[0-9]+"
    tags:
      # Match only clean semver tags: vX.Y.Z
      - 'v[0-9]+.[0-9]+.[0-9]+'
  workflow_dispatch:
    inputs:
      tag:
        description: 'Version tag to release (e.g., v0.9.0). Leave empty to sync dev docs.'
        required: false
        type: string

permissions:
  contents: write
  pull-requests: write

jobs:
  # Detect changed files for conditional job execution
  changed-files:
    runs-on: ubuntu-latest
    # Skip for tag pushes - version release doesn't need changed-files check
    if: github.ref_type != 'tag'
    outputs:
      docs: ${{ steps.changes.outputs.docs }}
    steps:
      - name: Checkout code
        uses: actions/checkout@v4
        with:
          fetch-depth: 0
      - name: Check for changes
        id: changes
        uses: ./.github/actions/changed-files
        with:
          gh_token: ${{ github.token }}

  #############################################################################
  # LINT JOBS - Run on PRs when docs/** files change
  #############################################################################

  fern-check:
    name: Fern Configuration Check
    needs: changed-files
    if: |
      github.ref_type != 'tag' &&
      needs.changed-files.outputs.docs == 'true' &&
      (github.event_name == 'pull_request' || startsWith(github.ref, 'refs/heads/pull-request/'))
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: '22'

      - name: Install Fern CLI
        run: npm install -g fern-api

      # Fern CLI expects a fern/ directory; create symlink after docs/ migration
      - name: Create fern directory symlink
        working-directory: docs
        run: ln -s . fern

      - name: Validate Fern configuration
        working-directory: docs
        run: fern check

  fern-broken-links:
    name: Fern Broken Links Check
    needs: changed-files
    if: |
      github.ref_type != 'tag' &&
      needs.changed-files.outputs.docs == 'true' &&
      (github.event_name == 'pull_request' || startsWith(github.ref, 'refs/heads/pull-request/'))
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: '22'

      - name: Install Fern CLI
        run: npm install -g fern-api

      # Fern CLI expects a fern/ directory; create symlink after docs/ migration
      - name: Create fern directory symlink
        working-directory: docs
        run: ln -s . fern

      - name: Check for broken links
        working-directory: docs
        run: fern docs broken-links

  #############################################################################
  # SYNC & PUBLISH/PREVIEW - Syncs docs content to docs-website structure
  # On main: commits, pushes, and publishes to Fern
  # On PRs: generates a preview URL and comments on the PR
  #############################################################################

  preview-or-publish-docs:
    name: Preview or publish docs
    needs: changed-files
    if: |
      github.ref_type != 'tag' &&
      (needs.changed-files.outputs.docs == 'true' || github.event_name == 'workflow_dispatch') &&
      (github.event.inputs.tag == '' || github.event.inputs.tag == null)
    runs-on: ubuntu-latest
    steps:
      - name: Determine context
        id: ctx
        run: |
          if [ "$GITHUB_REF" = "refs/heads/main" ]; then
            echo "is_main=true" >> $GITHUB_OUTPUT
          else
            echo "is_main=false" >> $GITHUB_OUTPUT
          fi

      - name: Checkout source branch
        uses: actions/checkout@v4
        with:
          path: source-checkout
          fetch-depth: 1

      - name: Checkout docs-website branch
        uses: actions/checkout@v4
        with:
          ref: docs-website
          path: docs-checkout
          fetch-depth: 1
          token: ${{ secrets.GITHUB_TOKEN }}
      - name: Sync dev content from main
        run: |
          # Sync pages/ directory (dev content)
          echo "Syncing pages/ to docs-website branch..."
          rm -rf docs-checkout/fern/pages
          cp -r source-checkout/docs/pages docs-checkout/fern/pages

          # Sync versions/dev.yml (dev navigation)
          echo "Syncing versions/dev.yml to docs-website branch..."
          cp source-checkout/docs/versions/dev.yml docs-checkout/fern/versions/dev.yml

          # Sync assets/ directory
          echo "Syncing assets/ to docs-website branch..."
          rm -rf docs-checkout/fern/assets
          cp -r source-checkout/docs/assets docs-checkout/fern/assets

          # Sync fern.config.json
          echo "Syncing fern.config.json to docs-website branch..."
          cp source-checkout/docs/fern.config.json docs-checkout/fern/fern.config.json

          # Sync .gitignore if it exists
          if [ -f source-checkout/docs/.gitignore ]; then
            cp source-checkout/docs/.gitignore docs-checkout/fern/.gitignore
          fi

          # Sync convert_callouts.py script
          if [ -f source-checkout/docs/convert_callouts.py ]; then
            cp source-checkout/docs/convert_callouts.py docs-checkout/fern/convert_callouts.py
          fi

          # Sync components/ directory (e.g., CustomFooter.tsx)
          if [ -d source-checkout/docs/components ]; then
            echo "Syncing components/ to docs-website branch..."
            rm -rf docs-checkout/fern/components
            cp -r source-checkout/docs/components docs-checkout/fern/components
          fi

          # Sync blogs/ directory
          if [ -d source-checkout/docs/blogs ]; then
            echo "Syncing blogs/ to docs-website branch..."
            rm -rf docs-checkout/fern/blogs
            cp -r source-checkout/docs/blogs docs-checkout/fern/blogs
          fi

          # Sync main.css
          if [ -f source-checkout/docs/main.css ]; then
            echo "Syncing main.css to docs-website branch..."
            cp source-checkout/docs/main.css docs-checkout/fern/main.css
          fi

      - name: Convert GitHub callouts to Fern format
        run: |
          echo "Converting GitHub-style callouts to Fern format in pages/..."
          python3 docs-checkout/fern/convert_callouts.py --dir docs-checkout/fern/pages
          echo "Callout conversion complete."

      - name: Update docs.yml preserving products
        run: |
          cd docs-checkout/fern

          # Save the full products[0] block from docs-website (versions, path, etc.)
          yq '.products[0]' docs.yml > /tmp/preserved_product.yml

          echo "Preserved products[0] block:"
          cat /tmp/preserved_product.yml

          # Copy docs.yml from source to get config updates (redirects, layout, etc.)
          cp ../../source-checkout/docs/docs.yml docs.yml

          # Restore the preserved products[0] block
          yq -i '.products[0] = load("/tmp/preserved_product.yml")' docs.yml

          echo "Updated docs.yml:"
          cat docs.yml

      - name: Check for changes
        id: changes
        run: |
          cd docs-checkout
          if git diff --quiet && git diff --cached --quiet; then
            echo "has_changes=false" >> $GITHUB_OUTPUT
            echo "No changes detected"
          else
            echo "has_changes=true" >> $GITHUB_OUTPUT
            echo "Changes detected:"
            git status --short
          fi

      - name: Setup Node.js
        if: steps.changes.outputs.has_changes == 'true'
        uses: actions/setup-node@v4
        with:
          node-version: '22'

      - name: Install Fern CLI
        if: steps.changes.outputs.has_changes == 'true'
        run: npm install -g fern-api

      ##########################################################################
      # PREVIEW - Generate a preview URL for docs changes
      ##########################################################################

      - name: Generate docs preview
        if: steps.ctx.outputs.is_main != 'true' && steps.changes.outputs.has_changes == 'true'
        id: preview
        working-directory: docs-checkout/fern
        env:
          FERN_TOKEN: ${{ secrets.FERN_TOKEN }}
        run: |
          OUTPUT=$(fern generate --docs --preview 2>&1)
          FERN_EXIT=$?
          echo "$OUTPUT"
          if [ $FERN_EXIT -ne 0 ]; then
            echo "::warning::Fern docs preview generation failed (exit $FERN_EXIT)"
          fi
          URL=$(echo "$OUTPUT" | grep -oP 'Published docs to \K\S+') || true
          if [ -n "$URL" ]; then
            echo "url=$URL" >> $GITHUB_OUTPUT
          fi

      - name: Comment preview URL on PR
        if: steps.ctx.outputs.is_main != 'true' && steps.preview.outputs.url != '' && startsWith(github.ref, 'refs/heads/pull-request/')
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          PR_NUM="${GITHUB_REF##*/}"
          gh pr comment "https://github.com/${{ github.repository }}/pull/${PR_NUM}" \
            --edit-last --create-if-none \
            --body "🌿 **Fern Docs Preview:** ${{ steps.preview.outputs.url }}/dev"

      ##########################################################################
      # PUSH AND PUBLISH - push changes to docs-website branch and publish docs
      ##########################################################################

      - name: Setup Git
        if: steps.ctx.outputs.is_main == 'true' && steps.changes.outputs.has_changes == 'true'
        run: |
          cd docs-checkout
          git config user.name "github-actions[bot]"
          git config user.email "github-actions[bot]@users.noreply.github.com"

      - name: Commit and push changes
        if: steps.ctx.outputs.is_main == 'true' && steps.changes.outputs.has_changes == 'true'
        run: |
          cd docs-checkout

          git add -A
          git commit -m "docs(fern): sync dev from main

          Automated sync of docs/ directory from main branch.
          Preserves versioned documentation snapshots.

          Source commit: ${{ github.sha }}"

          git push origin docs-website

          echo "Successfully synced dev docs to docs-website branch"

      - name: Publish Docs
        if: steps.ctx.outputs.is_main == 'true' && steps.changes.outputs.has_changes == 'true'
        env:
          FERN_TOKEN: ${{ secrets.FERN_TOKEN }}
        working-directory: docs-checkout/fern
        run: fern generate --docs

  #############################################################################
  # VERSION RELEASE - Run on new version tags (vX.Y.Z)
  #############################################################################

  release-version:
    name: Release Version to docs-website
    # Run on tag push OR manual dispatch with a tag specified
    if: |
      github.ref_type == 'tag' ||
      (github.event_name == 'workflow_dispatch' && github.event.inputs.tag != '' && github.event.inputs.tag != null)
    runs-on: ubuntu-latest
    steps:
      - name: Determine version tag
        id: version
        run: |
          if [ "${{ github.event_name }}" = "workflow_dispatch" ]; then
            TAG="${{ github.event.inputs.tag }}"
          else
            TAG="${GITHUB_REF#refs/tags/}"
          fi

          # Validate tag format (must be vX.Y.Z exactly)
          if ! echo "$TAG" | grep -qE '^v[0-9]+\.[0-9]+\.[0-9]+$'; then
            echo "::error::Invalid tag format: $TAG. Must be vX.Y.Z (e.g., v0.9.0)"
            exit 1
          fi

          # Extract version without 'v' prefix
          VERSION="${TAG#v}"
          echo "tag=$TAG" >> $GITHUB_OUTPUT
          echo "version=$VERSION" >> $GITHUB_OUTPUT
          echo "Processing version: $VERSION (tag: $TAG)"

      - name: Checkout docs-website branch
        uses: actions/checkout@v4
        with:
          ref: docs-website
          fetch-depth: 0
          token: ${{ secrets.GITHUB_TOKEN }}

      - name: Check if version already exists
        run: |
          TAG="${{ steps.version.outputs.tag }}"

          if [ -d "fern/pages-$TAG" ]; then
            echo "::error::Version $TAG already exists (fern/pages-$TAG directory found)"
            exit 1
          fi

          if [ -f "fern/versions/$TAG.yml" ]; then
            echo "::error::Version $TAG already exists (fern/versions/$TAG.yml found)"
            exit 1
          fi

          echo "Version $TAG does not exist yet, proceeding with release"

      - name: Setup Git
        run: |
          git config user.name "github-actions[bot]"
          git config user.email "github-actions[bot]@users.noreply.github.com"

      - name: Create versioned pages directory
        run: |
          TAG="${{ steps.version.outputs.tag }}"

          echo "Creating fern/pages-$TAG/ from fern/pages/..."

          # Copy current pages/ to pages-vX.Y.Z/
          cp -r fern/pages "fern/pages-$TAG"

          echo "Created fern/pages-$TAG/"
          ls -la "fern/pages-$TAG/" | head -20

      - name: Update GitHub links to 'main' to version tag
        run: |
          TAG="${{ steps.version.outputs.tag }}"

          echo "Updating GitHub links from 'tree/main' to 'tree/$TAG' in fern/pages-$TAG/..."

          # Find all markdown files and replace tree/main with tree/vX.Y.Z
          find "fern/pages-$TAG" -name "*.md" -o -name "*.mdx" | while read file; do
            if grep -q "github.com/ai-dynamo/dynamo/tree/main" "$file"; then
              echo "Updating: $file"
              sed -i "s|github.com/ai-dynamo/dynamo/tree/main|github.com/ai-dynamo/dynamo/tree/$TAG|g" "$file"
            fi
          done

          # Also update blob/main references (for direct file links)
          find "fern/pages-$TAG" -name "*.md" -o -name "*.mdx" | while read file; do
            if grep -q "github.com/ai-dynamo/dynamo/blob/main" "$file"; then
              echo "Updating blob links: $file"
              sed -i "s|github.com/ai-dynamo/dynamo/blob/main|github.com/ai-dynamo/dynamo/blob/$TAG|g" "$file"
            fi
          done

          echo "GitHub link update complete."

      - name: Convert GitHub callouts to Fern format
        run: |
          TAG="${{ steps.version.outputs.tag }}"

          echo "Converting GitHub-style callouts to Fern format in pages-$TAG/..."
          python3 fern/convert_callouts.py --dir "fern/pages-$TAG"
          echo "Callout conversion complete."

      - name: Create version config file
        run: |
          TAG="${{ steps.version.outputs.tag }}"
          VERSION="${{ steps.version.outputs.version }}"
          VERSION_FILE="fern/versions/$TAG.yml"

          echo "Creating version config: $VERSION_FILE"

          # Copy dev.yml as template
          cp fern/versions/dev.yml "$VERSION_FILE"

          # Update the comment at the top
          sed -i "s/# Navigation structure for Latest version/# Navigation structure for $TAG version/" "$VERSION_FILE"
          sed -i "s|# Matching https://docs.nvidia.com/dynamo/latest/|# Snapshot from tag $TAG|" "$VERSION_FILE"

          # Update all page paths from ../pages/ to ../pages-vX.Y.Z/
          sed -i "s|path: \.\./pages/|path: ../pages-$TAG/|g" "$VERSION_FILE"

          echo "Created $VERSION_FILE"
          echo "First 30 lines:"
          head -30 "$VERSION_FILE"

      - name: Update docs.yml with new version
        run: |
          TAG="${{ steps.version.outputs.tag }}"
          DOCS_FILE="fern/docs.yml"

          echo "Updating $DOCS_FILE to include $TAG..."

          # Check if version already in docs.yml
          if yq ".products[0].versions[] | select(.display-name == \"$TAG\")" "$DOCS_FILE" | grep -q .; then
            echo "Version $TAG already in docs.yml, skipping update"
            exit 0
          fi

          # Find the index of the "dev" entry and insert new version right after it
          DEV_IDX=$(yq '.products[0].versions | to_entries | map(select(.value.display-name == "dev")) | .[0].key' "$DOCS_FILE")
          INSERT_IDX=$((DEV_IDX + 1))

          yq -i "
            .products[0].versions |= (
              .[:$INSERT_IDX] +
              [{\"display-name\": \"$TAG\", \"path\": \"./versions/$TAG.yml\", \"slug\": \"$TAG\", \"availability\": \"stable\"}] +
              .[$INSERT_IDX:]
            )
          " "$DOCS_FILE"

          # Update the top-level entry to point to the new version
          yq -i ".products[0].path = \"./versions/$TAG.yml\"" "$DOCS_FILE"

          # Update the "Latest" entry to point to the new version
          yq -i ".products[0].versions[0].path = \"./versions/$TAG.yml\"" "$DOCS_FILE"
          yq -i ".products[0].versions[0].display-name = \"Latest ($TAG)\"" "$DOCS_FILE"

          echo "Updated docs.yml products/versions section:"
          yq '.products[0].versions' "$DOCS_FILE"

      - name: Commit and push changes
        run: |
          TAG="${{ steps.version.outputs.tag }}"

          git add "fern/pages-$TAG/"
          git add "fern/versions/$TAG.yml"
          git add fern/docs.yml

          git commit -m "docs(fern): release version $TAG

          - Created fern/pages-$TAG/ with documentation snapshot
          - Created fern/versions/$TAG.yml version navigation config
          - Updated fern/docs.yml to include $TAG in version list

          Automated by fern-docs workflow
          Source tag: $TAG"

          git push origin docs-website

          echo "Successfully released documentation for $TAG on docs-website branch"

      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: '22'

      - name: Install Fern CLI
        run: npm install -g fern-api

      - name: Publish Docs
        env:
          FERN_TOKEN: ${{ secrets.FERN_TOKEN }}
        working-directory: ./fern
        run: fern generate --docs
