#!/bin/bash
# Validate changed files before PR creation
# Runs: shellcheck, JSON validation, Python syntax check

set -euo pipefail

ERRORS=0

# Get changed files compared to main
CHANGED_FILES=$(git diff --name-only origin/main 2>/dev/null || git diff --name-only HEAD~1)

echo "Validating changed files..."

for file in $CHANGED_FILES; do
    [[ -f "$file" ]] || continue

    case "$file" in
        *.sh)
            if command -v shellcheck &>/dev/null; then
                if ! shellcheck -S warning "$file" 2>/dev/null; then
                    echo "FAIL: shellcheck $file"
                    ((ERRORS++))
                else
                    echo "OK: $file"
                fi
            else
                echo "SKIP: shellcheck not installed"
            fi
            ;;
        *.json)
            if ! python3 -m json.tool "$file" >/dev/null 2>&1; then
                echo "FAIL: invalid JSON $file"
                ((ERRORS++))
            else
                echo "OK: $file"
            fi
            ;;
        *.yaml|*.yml)
            if command -v yamllint &>/dev/null; then
                if ! yamllint -d relaxed "$file" 2>/dev/null; then
                    echo "FAIL: yamllint $file"
                    ((ERRORS++))
                else
                    echo "OK: $file"
                fi
            elif python3 -c "import yaml" 2>/dev/null; then
                if ! python3 -c "import yaml; yaml.safe_load(open('$file'))" 2>/dev/null; then
                    echo "FAIL: invalid YAML $file"
                    ((ERRORS++))
                else
                    echo "OK: $file"
                fi
            else
                echo "SKIP: no YAML validator"
            fi
            ;;
        *.py)
            if ! python3 -m py_compile "$file" 2>/dev/null; then
                echo "FAIL: Python syntax $file"
                ((ERRORS++))
            else
                echo "OK: $file"
            fi
            ;;
        *.md)
            echo "OK: $file (markdown, no validation)"
            ;;
        *)
            echo "SKIP: $file (no validator)"
            ;;
    esac
done

if [[ $ERRORS -gt 0 ]]; then
    echo ""
    echo "Validation failed with $ERRORS error(s)"
    exit 1
fi

echo ""
echo "All validations passed"
exit 0