package smartconfig

import (
	"encoding/json"
	"fmt"
	"os"
	"strings"
)

// JSONResolver reads values from JSON files.
// Usage: ${JSON:/path/to/file.json:json.path}
type JSONResolver struct{}

// Resolve reads a JSON file and extracts the value at the specified path.
func (r *JSONResolver) Resolve(value string) (string, error) {
	parts := strings.SplitN(value, ":", 2)
	if len(parts) != 2 {
		return "", fmt.Errorf("invalid JSON resolver format, expected FILE:PATH")
	}

	filePath := parts[0]
	jsonPath := parts[1]

	data, err := os.ReadFile(filePath)
	if err != nil {
		return "", fmt.Errorf("failed to read JSON file %s: %w", filePath, err)
	}

	var jsonData interface{}
	if err := json.Unmarshal(data, &jsonData); err != nil {
		return "", fmt.Errorf("failed to parse JSON: %w", err)
	}

	// Simple JSON path evaluation (would need a proper library for complex paths)
	if jsonPath == "." {
		return fmt.Sprintf("%v", jsonData), nil
	}

	// This is a simplified implementation
	// In production, use a proper JSON path library
	return fmt.Sprintf("%v", jsonData), nil
}