#!/usr/bin/env bash
# gstack-diff-scope — categorize what changed in the diff against a base branch
# Usage: source <(gstack-diff-scope main)  → sets SCOPE_FRONTEND=true SCOPE_BACKEND=false ...
# Or:    gstack-diff-scope main           → prints SCOPE_*=... lines
set -euo pipefail

BASE="${1:-main}"

# Get changed file list
FILES=$(git diff "${BASE}...HEAD" --name-only 2>/dev/null || git diff "${BASE}" --name-only 2>/dev/null || echo "")

if [ -z "$FILES" ]; then
  echo "SCOPE_FRONTEND=false"
  echo "SCOPE_BACKEND=false"
  echo "SCOPE_PROMPTS=false"
  echo "SCOPE_TESTS=false"
  echo "SCOPE_DOCS=false"
  echo "SCOPE_CONFIG=false"
  exit 0
fi

FRONTEND=false
BACKEND=false
PROMPTS=false
TESTS=false
DOCS=false
CONFIG=false

while IFS= read -r f; do
  case "$f" in
    # Frontend: CSS, views, components, templates
    *.css|*.scss|*.less|*.sass|*.pcss|*.module.css|*.module.scss) FRONTEND=true ;;
    *.tsx|*.jsx|*.vue|*.svelte|*.astro) FRONTEND=true ;;
    *.erb|*.haml|*.slim|*.hbs|*.ejs) FRONTEND=true ;;
    *.html) FRONTEND=true ;;
    tailwind.config.*|postcss.config.*) FRONTEND=true ;;
    app/views/*|*/components/*|styles/*|css/*|app/assets/stylesheets/*) FRONTEND=true ;;

    # Prompts: prompt builders, system prompts, generation services
    *prompt_builder*|*generation_service*|*writer_service*|*designer_service*) PROMPTS=true ;;
    *evaluator*|*scorer*|*classifier_service*|*analyzer*) PROMPTS=true ;;
    *voice*.rb|*writing*.rb|*prompt*.rb|*token*.rb) PROMPTS=true ;;
    app/services/chat_tools/*|app/services/x_thread_tools/*) PROMPTS=true ;;
    config/system_prompts/*) PROMPTS=true ;;

    # Tests
    *.test.*|*.spec.*|*_test.*|*_spec.*) TESTS=true ;;
    test/*|tests/*|spec/*|__tests__/*|cypress/*|e2e/*) TESTS=true ;;

    # Docs
    *.md) DOCS=true ;;

    # Config
    package.json|package-lock.json|yarn.lock|bun.lockb) CONFIG=true ;;
    Gemfile|Gemfile.lock) CONFIG=true ;;
    *.yml|*.yaml) CONFIG=true ;;
    .github/*) CONFIG=true ;;
    requirements.txt|pyproject.toml|go.mod|Cargo.toml|composer.json) CONFIG=true ;;

    # Backend: everything else that's code (excluding views/components already matched)
    *.rb|*.py|*.go|*.rs|*.java|*.php|*.ex|*.exs) BACKEND=true ;;
    *.ts|*.js) BACKEND=true ;;  # Non-component TS/JS is backend
  esac
done <<< "$FILES"

echo "SCOPE_FRONTEND=$FRONTEND"
echo "SCOPE_BACKEND=$BACKEND"
echo "SCOPE_PROMPTS=$PROMPTS"
echo "SCOPE_TESTS=$TESTS"
echo "SCOPE_DOCS=$DOCS"
echo "SCOPE_CONFIG=$CONFIG"