name: Validate Content

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]

jobs:
  markdown-lint:
    name: Lint Markdown
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Set up Node.js 20
        uses: actions/setup-node@v4
        with:
          node-version: "20"

      - name: Install markdownlint-cli2
        run: npm install -g markdownlint-cli2

      - name: Run markdownlint
        run: markdownlint-cli2 "**/*.md"

  check-links:
    name: Check Internal Links
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Validate internal cross-references
        run: |
          errors=0
          # Find all relative markdown links in .md files
          # Matches [text](relative/path) but skips http/https/mailto URLs and anchors
          while IFS= read -r file; do
            dir=$(dirname "$file")
            # Extract relative links from markdown link syntax [text](path)
            grep -oP '\[.*?\]\(\K[^)]+' "$file" 2>/dev/null | while read -r link; do
              # Skip external URLs, anchors, and template placeholders
              if echo "$link" | grep -qE '^(https?://|mailto:|#|\{)'; then
                continue
              fi
              # Strip anchor fragments from the link
              target=$(echo "$link" | sed 's/#.*//')
              # Skip if empty after stripping anchor
              if [ -z "$target" ]; then
                continue
              fi
              # Resolve relative to the file's directory
              resolved="$dir/$target"
              if [ ! -e "$resolved" ]; then
                echo "::error file=$file::Broken link: [$link] -> $resolved (file not found)"
                # Write to a temp file since we are in a subshell
                echo "1" >> /tmp/link_errors
              fi
            done
          done < <(find . -name '*.md' -not -path './.git/*')

          if [ -f /tmp/link_errors ]; then
            count=$(wc -l < /tmp/link_errors)
            echo "::error::Found $count broken internal link(s)"
            exit 1
          fi
          echo "All internal links are valid"

  validate-mermaid:
    name: Validate Mermaid Diagrams
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Set up Node.js 20
        uses: actions/setup-node@v4
        with:
          node-version: "20"

      - name: Install Mermaid CLI
        run: npm install -g @mermaid-js/mermaid-cli

      - name: Extract and validate Mermaid blocks
        run: |
          errors=0
          block_count=0

          # Extract all mermaid code blocks from markdown files
          while IFS= read -r file; do
            # Use awk to extract mermaid blocks
            awk '/^```mermaid$/{ found=1; next } /^```$/ && found { found=0; print "---END_BLOCK---" } found { print }' "$file" | \
            while IFS= read -r line; do
              if [ "$line" = "---END_BLOCK---" ]; then
                if [ -s /tmp/mermaid_block.mmd ]; then
                  block_count=$((block_count + 1))
                  if ! mmdc -i /tmp/mermaid_block.mmd -o /tmp/mermaid_out.svg 2>/tmp/mermaid_err.txt; then
                    echo "::error file=$file::Invalid Mermaid diagram in $file"
                    cat /tmp/mermaid_err.txt
                    echo "1" >> /tmp/mermaid_errors
                  fi
                  rm -f /tmp/mermaid_block.mmd /tmp/mermaid_out.svg
                fi
              else
                echo "$line" >> /tmp/mermaid_block.mmd
              fi
            done
          done < <(find . -name '*.md' -not -path './.git/*')

          if [ -f /tmp/mermaid_errors ]; then
            count=$(wc -l < /tmp/mermaid_errors)
            echo "::error::Found $count invalid Mermaid diagram(s)"
            exit 1
          fi
          echo "All Mermaid diagrams are valid"

  json-validate:
    name: Validate JSON
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Set up Node.js 20
        uses: actions/setup-node@v4
        with:
          node-version: "20"

      - name: Validate JSON syntax
        run: |
          errors=0
          while IFS= read -r file; do
            if ! node -e "JSON.parse(require('fs').readFileSync('$file', 'utf8'))" 2>/dev/null; then
              echo "::error file=$file::Invalid JSON: $file"
              errors=$((errors + 1))
            else
              echo "Valid JSON: $file"
            fi
          done < <(find . -name '*.json' -not -path './.git/*')

          if [ "$errors" -gt 0 ]; then
            echo "::error::Found $errors invalid JSON file(s)"
            exit 1
          fi
          echo "All JSON files are valid"