package keyretriever

import (
	"errors"
	"fmt"
)

// KeyRetriever retrieves the master encryption key for a Chromium-based browser.
// Each platform has different implementations:
//   - macOS: Keychain access (security command) or gcoredump exploit
//   - Windows: DPAPI decryption of Local State file
//   - Linux: D-Bus Secret Service or fallback to "peanuts" password
type KeyRetriever interface {
	RetrieveKey(storage, localStatePath string) ([]byte, error)
}

// ChainRetriever tries multiple retrievers in order, returning the first success.
// Used on macOS (gcoredump → password → security) and Linux (D-Bus → peanuts).
type ChainRetriever struct {
	retrievers []KeyRetriever
}

// NewChain creates a ChainRetriever that tries each retriever in order.
func NewChain(retrievers ...KeyRetriever) KeyRetriever {
	return &ChainRetriever{retrievers: retrievers}
}

func (c *ChainRetriever) RetrieveKey(storage, localStatePath string) ([]byte, error) {
	var errs []error
	for _, r := range c.retrievers {
		key, err := r.RetrieveKey(storage, localStatePath)
		if err == nil && len(key) > 0 {
			return key, nil
		}
		if err != nil {
			errs = append(errs, fmt.Errorf("%T: %w", r, err))
		}
	}
	return nil, fmt.Errorf("all retrievers failed: %w", errors.Join(errs...))
}