name: LDR Research (reusable)

# Reusable workflow that runs the LDR research script on a caller-supplied
# query and produces a comment-ready markdown blob (uploaded as an
# artifact). Callers download the artifact and post it to their target
# (PR comment, issue comment, Reddit, etc.). This workflow does NOT post
# anywhere — that's caller-specific.

on:
  workflow_call:
    inputs:
      query:
        description: 'Fully-assembled research prompt. The caller does all prompt engineering.'
        type: string
        required: true
      model:
        description: 'OpenRouter model slug. Empty falls back to vars.LDR_RESEARCH_MODEL then a hard default.'
        type: string
        default: ''
      provider:
        description: 'LLM provider.'
        type: string
        default: 'openrouter'
      search-tool:
        description: 'Search tool.'
        type: string
        default: 'serper'
      strategy:
        description: 'LDR search strategy.'
        type: string
        default: 'langgraph-agent'
      iterations:
        description: 'Override the strategy iteration cap. 0 keeps the strategy default.'
        type: number
        default: 0
      max-query-length:
        description: 'Backstop truncation on the query string before invoking the script.'
        type: number
        default: 12000
      max-sources:
        description: 'Cap sources rendered in the markdown.'
        type: number
        default: 10
      comment-header:
        description: 'Top header line of the formatted markdown.'
        type: string
        default: '## LDR Research Results'
      comment-subheader:
        description: 'Optional second-line subheader.'
        type: string
        default: ''
      comment-footer:
        description: 'Footer line. Reddit will swap in a bot disclaimer.'
        type: string
        default: '_Generated by [Local Deep Research](https://github.com/LearningCircuit/local-deep-research) E2E test_'
      include-sources-section:
        description: 'Render a dedicated sources section. Reddit will set false to fit length caps.'
        type: boolean
        default: true
      output-truncate-chars:
        description: 'Truncate the rendered markdown to this many chars. 0 disables truncation.'
        type: number
        default: 0
      runner:
        description: 'Runner label.'
        type: string
        default: 'ubuntu-latest'
      artifact-suffix:
        description: 'Optional disambiguator appended to the artifact name. Use a unique value per matrix entry when calling this workflow multiple times in one caller run.'
        type: string
        default: ''
    secrets:
      OPENROUTER_API_KEY:
        required: true
      SERPER_API_KEY:
        required: true
    outputs:
      comment-artifact-name:
        description: 'Name of the artifact containing comment.md and response.json.'
        value: ${{ jobs.research.outputs.comment-artifact-name }}
      success:
        description: "'true' if LDR returned valid non-error JSON."
        value: ${{ jobs.research.outputs.success }}

permissions: {}

jobs:
  research:
    name: Run LDR research
    runs-on: ${{ inputs.runner }}
    permissions:
      contents: read
    outputs:
      comment-artifact-name: ${{ steps.artifact-name.outputs.name }}
      success: ${{ steps.run-script.outputs.success }}
    env:
      QUERY: ${{ inputs.query }}
      MAX_QUERY_LENGTH: ${{ inputs.max-query-length }}
      MAX_SOURCES: ${{ inputs.max-sources }}
      COMMENT_HEADER: ${{ inputs.comment-header }}
      COMMENT_SUBHEADER: ${{ inputs.comment-subheader }}
      COMMENT_FOOTER: ${{ inputs.comment-footer }}
      INCLUDE_SOURCES: ${{ inputs.include-sources-section }}
      OUTPUT_TRUNCATE_CHARS: ${{ inputs.output-truncate-chars }}
    steps:
      - name: Harden the runner (Audit all outbound calls)
        uses: step-security/harden-runner@9af89fc71515a100421586dfdb3dc9c984fbf411 # v2.19.4
        with:
          egress-policy: audit

      - name: Checkout repository
        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
          fetch-depth: 1

      - name: Install jq
        run: sudo apt-get update && sudo apt-get install -y jq

      - name: Compute artifact name
        id: artifact-name
        env:
          SUFFIX: ${{ inputs.artifact-suffix }}
        run: |
          NAME="ldr-research-${{ github.run_id }}-${{ github.run_attempt }}-${{ github.job }}"
          if [ -n "$SUFFIX" ]; then
            # Sanitize: artifact names allow [A-Za-z0-9._-] only.
            SAFE_SUFFIX=$(printf '%s' "$SUFFIX" | tr -c 'A-Za-z0-9._-' '_')
            NAME="${NAME}-${SAFE_SUFFIX}"
          fi
          echo "name=$NAME" >> "$GITHUB_OUTPUT"

      - name: Resolve model
        id: resolve-model
        env:
          INPUT_MODEL: ${{ inputs.model }}
          REPO_VAR_MODEL: ${{ vars.LDR_RESEARCH_MODEL }}
        run: |
          if [ -n "$INPUT_MODEL" ]; then
            echo "model=$INPUT_MODEL" >> "$GITHUB_OUTPUT"
          elif [ -n "$REPO_VAR_MODEL" ]; then
            echo "model=$REPO_VAR_MODEL" >> "$GITHUB_OUTPUT"
          else
            echo "model=google/gemini-2.0-flash-001" >> "$GITHUB_OUTPUT"
          fi

      - name: Set up PDM
        uses: pdm-project/setup-pdm@973541a5febeafcfdadf8a51211435be6ecfd90f # v4.5
        with:
          python-version: '3.12'
          cache: true

      - name: Install LDR
        run: pdm install

      - name: Write query to file (with backstop truncation)
        run: |
          # Truncate by total byte count, not per-line. Avoids putting the
          # entire query on the command line where it could exceed ARG_MAX.
          QUERY_BYTES=$(printf '%s' "$QUERY" | wc -c)
          if [ "$QUERY_BYTES" -gt "$MAX_QUERY_LENGTH" ]; then
            printf '%s' "$QUERY" | head -c "$MAX_QUERY_LENGTH" > query.txt
            printf '\n... (truncated)\n' >> query.txt
            echo "Query truncated: $QUERY_BYTES -> $MAX_QUERY_LENGTH bytes"
          else
            printf '%s' "$QUERY" > query.txt
          fi
          echo "Final query size: $(wc -c < query.txt) bytes"

      - name: Run LDR Research
        id: run-script
        env:
          OPENROUTER_API_KEY: ${{ secrets.OPENROUTER_API_KEY }}
          SERPER_API_KEY: ${{ secrets.SERPER_API_KEY }}
          LDR_PROVIDER: ${{ inputs.provider }}
          LDR_SEARCH_TOOL: ${{ inputs.search-tool }}
          LDR_RESEARCH_MODEL: ${{ steps.resolve-model.outputs.model }}
          LDR_STRATEGY: ${{ inputs.strategy }}
          ITERATIONS: ${{ inputs.iterations }}
        run: |
          set +e
          if [ "$ITERATIONS" -gt 0 ] 2>/dev/null; then
            pdm run python scripts/ldr-research.py --iterations "$ITERATIONS" \
              < query.txt 2> >(tee stderr.log >&2) > response.json
          else
            pdm run python scripts/ldr-research.py \
              < query.txt 2> >(tee stderr.log >&2) > response.json
          fi
          LDR_EXIT_CODE=$?
          set -e

          echo "=== Response (first 2000 chars): ==="
          head -c 2000 response.json
          echo ""
          echo "=== End response ==="

          # Catches SIGABRT/native crashes where stdout never flushed; JSON check alone can't see this.
          if [ "$LDR_EXIT_CODE" -ne 0 ]; then
            LAST_ERR=$(tail -c 500 stderr.log 2>/dev/null || echo "")
            echo "::error::ldr-research.py exited with code $LDR_EXIT_CODE: $LAST_ERR"
            echo "success=false" >> "$GITHUB_OUTPUT"
            exit 1
          fi

          # `jq .` exits 0 on a zero-byte file, so guard explicitly.
          if [ ! -s response.json ]; then
            echo "::error::response.json is empty"
            echo "success=false" >> "$GITHUB_OUTPUT"
            exit 1
          fi

          # Shape validation: must be a JSON object.
          if ! jq -e 'type == "object"' response.json > /dev/null 2>&1; then
            echo "::error::Response is not a JSON object"
            echo "success=false" >> "$GITHUB_OUTPUT"
            exit 1
          fi

          ERROR=$(jq -r '.error // empty' response.json)
          if [ -n "$ERROR" ]; then
            echo "::error::LDR error: $ERROR"
            echo "success=false" >> "$GITHUB_OUTPUT"
            exit 1
          fi

          # Empty .research would still produce a hollow downstream comment.
          RESEARCH=$(jq -r '.research // empty' response.json)
          if [ -z "$RESEARCH" ]; then
            echo "::error::Response missing or empty .research field"
            echo "success=false" >> "$GITHUB_OUTPUT"
            exit 1
          fi

          echo "success=true" >> "$GITHUB_OUTPUT"
          echo "✅ Research completed"

      - name: Build comment markdown
        run: |
          jq -r '.research' response.json > result.md

          # Optional sources section
          if [ "$INCLUDE_SOURCES" = "true" ]; then
            SOURCES=$(jq -r --argjson cap "$MAX_SOURCES" \
              '.sources[:$cap][] | "- [\(.title // "Source")](\(.link // .url // ""))"' \
              response.json 2>/dev/null || echo "")
          else
            SOURCES=""
          fi

          {
            echo "$COMMENT_HEADER"
            echo ""
            if [ -n "$COMMENT_SUBHEADER" ]; then
              echo "$COMMENT_SUBHEADER"
              echo ""
            fi
            cat result.md
            echo ""
            if [ -n "$SOURCES" ]; then
              echo "### 🔍 Search Sources"
              echo ""
              echo "$SOURCES"
              echo ""
            fi
            echo "---"
            echo "$COMMENT_FOOTER"
          } > comment.md

          # Optional truncation (Reddit will use this)
          if [ "$OUTPUT_TRUNCATE_CHARS" -gt 0 ] 2>/dev/null; then
            CURRENT=$(wc -c < comment.md)
            if [ "$CURRENT" -gt "$OUTPUT_TRUNCATE_CHARS" ]; then
              # Truncate at last paragraph break before the limit, with a budget
              # for the trailing marker.
              MARKER='…[truncated]'
              BUDGET=$((OUTPUT_TRUNCATE_CHARS - ${#MARKER} - 1))
              head -c "$BUDGET" comment.md > comment.md.tmp
              # Trim trailing partial line so we end on a clean paragraph
              awk 'BEGIN{RS=""} {gsub(/[[:space:]]+$/,""); print}' \
                comment.md.tmp > comment.md
              echo "" >> comment.md
              echo "$MARKER" >> comment.md
              rm -f comment.md.tmp
              echo "Truncated comment.md to $OUTPUT_TRUNCATE_CHARS chars."
            fi
          fi

          echo "Final comment.md size: $(wc -c < comment.md) bytes"

      - name: Upload research artifact
        if: always()
        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
        with:
          name: ${{ steps.artifact-name.outputs.name }}
          path: |
            comment.md
            response.json
            stderr.log
          if-no-files-found: ignore
          retention-days: 7