package sts

import (
	"context"
	"fmt"
	"sync"
	"time"
)

// MemorySessionStore implements SessionStore using in-memory storage
type MemorySessionStore struct {
	sessions map[string]*SessionInfo
	mutex    sync.RWMutex
}

// NewMemorySessionStore creates a new memory-based session store
func NewMemorySessionStore() *MemorySessionStore {
	return &MemorySessionStore{
		sessions: make(map[string]*SessionInfo),
	}
}

// StoreSession stores session information in memory
func (m *MemorySessionStore) StoreSession(ctx context.Context, sessionId string, session *SessionInfo) error {
	if sessionId == "" {
		return fmt.Errorf("session ID cannot be empty")
	}

	if session == nil {
		return fmt.Errorf("session cannot be nil")
	}

	m.mutex.Lock()
	defer m.mutex.Unlock()

	m.sessions[sessionId] = session
	return nil
}

// GetSession retrieves session information from memory
func (m *MemorySessionStore) GetSession(ctx context.Context, sessionId string) (*SessionInfo, error) {
	if sessionId == "" {
		return nil, fmt.Errorf("session ID cannot be empty")
	}

	m.mutex.RLock()
	defer m.mutex.RUnlock()

	session, exists := m.sessions[sessionId]
	if !exists {
		return nil, fmt.Errorf("session not found")
	}

	// Check if session has expired
	if time.Now().After(session.ExpiresAt) {
		return nil, fmt.Errorf("session has expired")
	}

	return session, nil
}

// RevokeSession revokes a session from memory
func (m *MemorySessionStore) RevokeSession(ctx context.Context, sessionId string) error {
	if sessionId == "" {
		return fmt.Errorf("session ID cannot be empty")
	}

	m.mutex.Lock()
	defer m.mutex.Unlock()

	delete(m.sessions, sessionId)
	return nil
}

// CleanupExpiredSessions removes expired sessions from memory
func (m *MemorySessionStore) CleanupExpiredSessions(ctx context.Context) error {
	m.mutex.Lock()
	defer m.mutex.Unlock()

	now := time.Now()
	for sessionId, session := range m.sessions {
		if now.After(session.ExpiresAt) {
			delete(m.sessions, sessionId)
		}
	}

	return nil
}

// FilerSessionStore implements SessionStore using SeaweedFS filer
type FilerSessionStore struct {
	// TODO: Add filer client configuration
	basePath string
}

// NewFilerSessionStore creates a new filer-based session store
func NewFilerSessionStore(config map[string]interface{}) (*FilerSessionStore, error) {
	// TODO: Implement filer session store initialization
	// 1. Parse configuration for filer connection
	// 2. Set up filer client
	// 3. Configure base path for session storage

	return nil, fmt.Errorf("filer session store not implemented yet")
}

// StoreSession stores session information in filer
func (f *FilerSessionStore) StoreSession(ctx context.Context, sessionId string, session *SessionInfo) error {
	// TODO: Implement filer session storage
	// 1. Serialize session information to JSON/protobuf
	// 2. Store in filer at configured path + sessionId
	// 3. Handle errors and retries

	return fmt.Errorf("filer session storage not implemented yet")
}

// GetSession retrieves session information from filer
func (f *FilerSessionStore) GetSession(ctx context.Context, sessionId string) (*SessionInfo, error) {
	// TODO: Implement filer session retrieval
	// 1. Read session data from filer
	// 2. Deserialize JSON/protobuf to SessionInfo
	// 3. Check expiration
	// 4. Handle not found cases

	return nil, fmt.Errorf("filer session retrieval not implemented yet")
}

// RevokeSession revokes a session from filer
func (f *FilerSessionStore) RevokeSession(ctx context.Context, sessionId string) error {
	// TODO: Implement filer session revocation
	// 1. Delete session file from filer
	// 2. Handle errors

	return fmt.Errorf("filer session revocation not implemented yet")
}

// CleanupExpiredSessions removes expired sessions from filer
func (f *FilerSessionStore) CleanupExpiredSessions(ctx context.Context) error {
	// TODO: Implement filer session cleanup
	// 1. List all session files in base path
	// 2. Read and check expiration times
	// 3. Delete expired sessions

	return fmt.Errorf("filer session cleanup not implemented yet")
}