name: Update Nix Packages with nix-update

on:
  schedule:
    - cron: "0 2 * * *"
  workflow_dispatch:
    inputs:
      package:
        description: "Specific package to update (optional)"
        required: false
        type: string

env:
  GIT_AUTHOR_NAME: "nix-update bot"
  GIT_AUTHOR_EMAIL: "bot@m3ta.dev"
  GIT_COMMITTER_NAME: "nix-update bot"
  GIT_COMMITTER_EMAIL: "bot@m3ta.dev"
  REPO_DIR: "/tmp/nixpkgs" # Centralized workspace path

jobs:
  nix-update:
    runs-on: nixos
    steps:
      - name: Setup Environment and Authenticate
        run: |
          # 1. Clean Workspace
          if [ -d "$REPO_DIR" ]; then rm -rf "$REPO_DIR"; fi

          # 2. Configure Git Credentials
          # Using 'store' helper is robust and avoids interactive prompts
          git config --global credential.helper store
          echo "https://m3tam3re:${{ secrets.NIX_UPDATE_TOKEN }}@code.m3ta.dev" > ~/.git-credentials
          chmod 600 ~/.git-credentials

          # 3. Configure Git Identity
          git config --global user.name "$GIT_AUTHOR_NAME"
          git config --global user.email "$GIT_AUTHOR_EMAIL"
          git config --global init.defaultBranch master

          # 4. Verify Authentication (Fail fast)
          if command -v tea &> /dev/null; then
            echo "Verifying API access..."
            tea login delete m3ta >/dev/null 2>&1 || true
            if ! tea login add --name m3ta --url https://code.m3ta.dev --token "${{ secrets.NIX_UPDATE_TOKEN }}"; then
               echo "❌ Authentication failed. Check NIX_UPDATE_TOKEN."
               exit 1
            fi
            echo "✓ Authentication successful."
          fi

      - name: Checkout Repository
        run: |
          # Clone using explicit username to match credentials
          git clone --no-single-branch \
            "https://m3tam3re@code.m3ta.dev/m3tam3re/nixpkgs.git" \
            "$REPO_DIR"

      - name: Check Prerequisites
        id: check
        run: |
          cd "$REPO_DIR"
          
          # Check for packages directory
          if [ ! -d "pkgs" ]; then
             echo "❌ Error: 'pkgs' directory not found."
             exit 1
          fi

          # Check for flake.nix
          if [ -f "flake.nix" ]; then
            echo "has_flake=true" >> $GITHUB_OUTPUT
          else
            echo "has_flake=false" >> $GITHUB_OUTPUT
          fi

      - name: Update Packages
        id: update
        run: |
          cd "$REPO_DIR"
          set -e

          TIMESTAMP=$(date +%Y%m%d-%H%M%S)
          BRANCH_NAME="nix-update-${TIMESTAMP}"

          git checkout -b "${BRANCH_NAME}"

          UPDATES_FOUND=false
          UPDATED_PACKAGES=""

          # Helper to verify commits
          check_commit() {
             [ "$1" != "$(git rev-parse HEAD)" ] && echo "true" || echo "false"
          }

          run_update() {
             local pkg=$1
             local before_hash=$(git rev-parse HEAD)
             
             echo "Checking $pkg..."
             # Run nix-update, capturing output to log but allowing failure
             if nix-update --flake --commit "$pkg" 2>&1 | tee /tmp/update-${pkg}.log; then
                if [ "$(check_commit "$before_hash")" = "true" ]; then
                   echo "✓ Updated $pkg"
                   return 0
                fi
             fi
             
             # Log failure reason if not just "up to date"
             if ! grep -q "already up to date\|No new version found" /tmp/update-${pkg}.log; then
                echo "⚠️ Update failed for $pkg"
             fi
             return 1
          }

          if [ -n "${{ inputs.package }}" ]; then
            # Single package mode
            pkg="${{ inputs.package }}"
            if [ -d "pkgs/$pkg" ]; then
               if run_update "$pkg"; then
                  UPDATES_FOUND=true
                  UPDATED_PACKAGES="$pkg"
               fi
            else
               echo "✗ Package 'pkgs/$pkg' not found"
            fi
          else
            # All packages mode
            PACKAGES=$(find pkgs -mindepth 1 -maxdepth 1 -type d -not -name default.nix -not -name AGENTS.md -exec basename {} \; 2>/dev/null | sort)
            
            if [ -z "$PACKAGES" ]; then
              echo "No packages found to update"
              echo "has_updates=false" >> $GITHUB_OUTPUT
              exit 0
            fi

            for pkg in $PACKAGES; do
              if run_update "$pkg"; then
                 UPDATES_FOUND=true
                 UPDATED_PACKAGES="${UPDATED_PACKAGES}, $pkg"
              fi
            done
          fi

          # Finalize
          UPDATED_PACKAGES=$(echo "$UPDATED_PACKAGES" | sed 's/^, //')
          COMMIT_COUNT=$(git rev-list --count master..HEAD)
          
          if [ "$COMMIT_COUNT" -gt 0 ]; then
            echo "✓ $COMMIT_COUNT updates committed."
            echo "has_updates=true" >> $GITHUB_OUTPUT
            echo "updated_packages=${UPDATED_PACKAGES}" >> $GITHUB_OUTPUT
            echo "branch_name=${BRANCH_NAME}" >> $GITHUB_OUTPUT
          else
            echo "ℹ️ No updates found."
            echo "has_updates=false" >> $GITHUB_OUTPUT
            git checkout master
            git branch -D "${BRANCH_NAME}" 2>/dev/null || true
          fi

      - name: Verify Builds
        if: steps.update.outputs.has_updates == 'true'
        run: |
          cd "$REPO_DIR"
          IFS=', ' read -ra PKGS <<< "${{ steps.update.outputs.updated_packages }}"
          
          for pkg in "${PKGS[@]}"; do
            echo "Building $pkg..."
            if ! nix build .#$pkg; then
              echo "❌ Build failed for $pkg"
              exit 1
            fi
            echo "✓ Build successful"
          done

      - name: Push and PR
        if: steps.update.outputs.has_updates == 'true'
        run: |
          cd "$REPO_DIR"
          BRANCH="${{ steps.update.outputs.branch_name }}"
          PACKAGES="${{ steps.update.outputs.updated_packages }}"

          echo "Pushing branch $BRANCH..."
          git push origin "$BRANCH"

          echo "Creating Pull Request..."
          COMMITS=$(git log origin/master..HEAD --pretty=format:"%h %s" | sed 's/^/- /')
          
          tea pr create \
            --head "$BRANCH" \
            --base master \
            --title "chore: update packages with nix-update" \
            --body "$(printf "Automated package updates.\n\nUpdated packages:\n%s\n\nCommits:\n%s" "$PACKAGES" "$COMMITS")" \
            --assignees m3tam3re \
            --labels automated-update

      - name: Cleanup Credentials
        if: always() # Run even if job fails
        run: |
          rm -f ~/.git-credentials
          # Optional: Clear repo to save space
          # rm -rf "$REPO_DIR"

      - name: Summary
        if: always()
        run: |
          if [ "${{ steps.update.outputs.has_updates }}" = "true" ]; then
            echo "✅ Successfully updated: ${{ steps.update.outputs.updated_packages }}"
          else
            echo "ℹ️ No updates required."
          fi