package vaultik

import (
	"bytes"
	"context"
	"fmt"
	"io"
	"os"

	"git.eeqj.de/sneak/vaultik/internal/config"
	"git.eeqj.de/sneak/vaultik/internal/crypto"
	"git.eeqj.de/sneak/vaultik/internal/database"
	"git.eeqj.de/sneak/vaultik/internal/globals"
	"git.eeqj.de/sneak/vaultik/internal/snapshot"
	"git.eeqj.de/sneak/vaultik/internal/storage"
	"github.com/spf13/afero"
	"go.uber.org/fx"
)

// Vaultik contains all dependencies needed for vaultik operations
type Vaultik struct {
	Globals         *globals.Globals
	Config          *config.Config
	DB              *database.DB
	Repositories    *database.Repositories
	Storage         storage.Storer
	ScannerFactory  snapshot.ScannerFactory
	SnapshotManager *snapshot.SnapshotManager
	Shutdowner      fx.Shutdowner
	Fs              afero.Fs

	// Context management
	ctx    context.Context
	cancel context.CancelFunc

	// IO
	Stdout io.Writer
	Stderr io.Writer
	Stdin  io.Reader
}

// VaultikParams contains all parameters for New that can be provided by fx
type VaultikParams struct {
	fx.In

	Globals         *globals.Globals
	Config          *config.Config
	DB              *database.DB
	Repositories    *database.Repositories
	Storage         storage.Storer
	ScannerFactory  snapshot.ScannerFactory
	SnapshotManager *snapshot.SnapshotManager
	Shutdowner      fx.Shutdowner
	Fs              afero.Fs `optional:"true"`
}

// New creates a new Vaultik instance with proper context management
// It automatically includes crypto capabilities if age_secret_key is configured
func New(params VaultikParams) *Vaultik {
	ctx, cancel := context.WithCancel(context.Background())

	// Use provided filesystem or default to OS filesystem
	fs := params.Fs
	if fs == nil {
		fs = afero.NewOsFs()
	}

	// Set filesystem on SnapshotManager
	params.SnapshotManager.SetFilesystem(fs)

	return &Vaultik{
		Globals:         params.Globals,
		Config:          params.Config,
		DB:              params.DB,
		Repositories:    params.Repositories,
		Storage:         params.Storage,
		ScannerFactory:  params.ScannerFactory,
		SnapshotManager: params.SnapshotManager,
		Shutdowner:      params.Shutdowner,
		Fs:              fs,
		ctx:             ctx,
		cancel:          cancel,
		Stdout:          os.Stdout,
		Stderr:          os.Stderr,
		Stdin:           os.Stdin,
	}
}

// Context returns the Vaultik's context
func (v *Vaultik) Context() context.Context {
	return v.ctx
}

// SetContext sets the Vaultik's context (primarily for testing)
func (v *Vaultik) SetContext(ctx context.Context) {
	v.ctx = ctx
}

// Cancel cancels the Vaultik's context
func (v *Vaultik) Cancel() {
	v.cancel()
}

// CanDecrypt returns true if this Vaultik instance has decryption capabilities
func (v *Vaultik) CanDecrypt() bool {
	return v.Config.AgeSecretKey != ""
}

// GetEncryptor creates a new Encryptor instance based on the configured age recipients
// Returns an error if no recipients are configured
func (v *Vaultik) GetEncryptor() (*crypto.Encryptor, error) {
	if len(v.Config.AgeRecipients) == 0 {
		return nil, fmt.Errorf("no age recipients configured")
	}
	return crypto.NewEncryptor(v.Config.AgeRecipients)
}

// GetDecryptor creates a new Decryptor instance based on the configured age secret key
// Returns an error if no secret key is configured
func (v *Vaultik) GetDecryptor() (*crypto.Decryptor, error) {
	if v.Config.AgeSecretKey == "" {
		return nil, fmt.Errorf("no age secret key configured")
	}
	return crypto.NewDecryptor(v.Config.AgeSecretKey)
}

// GetFilesystem returns the filesystem instance used by Vaultik
func (v *Vaultik) GetFilesystem() afero.Fs {
	return v.Fs
}

// printfStdout writes formatted output to stdout.
func (v *Vaultik) printfStdout(format string, args ...any) {
	_, _ = fmt.Fprintf(v.Stdout, format, args...)
}

// printlnStdout writes a line to stdout.
func (v *Vaultik) printlnStdout(args ...any) {
	_, _ = fmt.Fprintln(v.Stdout, args...)
}

// printfStderr writes formatted output to stderr.
func (v *Vaultik) printfStderr(format string, args ...any) {
	_, _ = fmt.Fprintf(v.Stderr, format, args...)
}

// scanStdin reads a line of input from stdin.
func (v *Vaultik) scanStdin(a ...any) (int, error) {
	return fmt.Fscanln(v.Stdin, a...)
}

// TestVaultik wraps a Vaultik with captured stdout/stderr for testing
type TestVaultik struct {
	*Vaultik
	Stdout *bytes.Buffer
	Stderr *bytes.Buffer
	Stdin  *bytes.Buffer
}

// NewForTesting creates a minimal Vaultik instance for testing purposes.
// Only the Storage field is populated; other fields are nil.
// Returns a TestVaultik that captures stdout/stderr in buffers.
func NewForTesting(storage storage.Storer) *TestVaultik {
	ctx, cancel := context.WithCancel(context.Background())
	stdout := &bytes.Buffer{}
	stderr := &bytes.Buffer{}
	stdin := &bytes.Buffer{}
	return &TestVaultik{
		Vaultik: &Vaultik{
			Storage: storage,
			ctx:     ctx,
			cancel:  cancel,
			Stdout:  stdout,
			Stderr:  stderr,
			Stdin:   stdin,
		},
		Stdout: stdout,
		Stderr: stderr,
		Stdin:  stdin,
	}
}