#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>

#import "VENCore.h"

#import "VENErrors.h"
#import "VENPermissionConstants.h"
#import "VENSession.h"
#import "VENTransaction+VenmoSDK.h"

typedef NS_ENUM(NSUInteger, VENTransactionMethod) {
    // Indicates that the SDK should send transactions by switching to the Venmo app.
    VENTransactionMethodAppSwitch,
    // Indicates that the SDK should send transactions via the Venmo API.
    // If there is no open session, the SDK will fall back to sending transactions via app switch.
    VENTransactionMethodAPI
};

@class VENUserSDK, VENSession;

typedef void (^VENTransactionCompletionHandler)(VENTransaction *transaction, BOOL success, NSError *error);
typedef void (^VENRefreshTokenCompletionHandler)(NSString *accessToken, BOOL success, NSError *error);
typedef void (^VENGenericRequestCompletionHandler)(id object, BOOL success, NSError *error);
typedef void (^VENOAuthCompletionHandler)(BOOL success, NSError *error);

#define VEN_CURRENT_SDK_VERSION @"1.2.0"

@interface Venmo : NSObject

@property (copy, nonatomic, readonly) NSString *appId;
@property (copy, nonatomic, readonly) NSString *appSecret;
@property (copy, nonatomic, readonly) NSString *appName;
@property (strong, nonatomic) VENSession *session;
@property (copy, nonatomic, readonly) VENTransactionCompletionHandler transactionCompletionHandler;
@property (copy, nonatomic, readonly) VENOAuthCompletionHandler OAuthCompletionHandler;

- (BOOL)handleOpenURL:(NSURL *)url;


/// The SDK's default transaction method. Default is VENTransactionMethodAppSwitch.
@property (assign, nonatomic, readwrite) VENTransactionMethod defaultTransactionMethod;


/**
 * Starts the Venmo SDK.
 * @param appId Your app ID
 * @param appSecret Your app secret
 * @param appName Your app name (used in Venmo app to show "via [appName]"). Defaults to "Bundle name" in your Info.plist
 * @return A boolean value indicating whether a cached session was found for the given app details.
 * If this method returns NO, you will need to create a session by calling requestPermissions:withCompletionHandler.
 */
+ (BOOL)startWithAppId:(NSString *)appId
                secret:(NSString *)appSecret
                  name:(NSString *)appName;


/**
 * Returns the shared Venmo instance.
 * @return The shared Venmo instance
 */
+ (instancetype)sharedInstance;


/**
 * Returns YES if the current device has the Venmo app installed
 */
+ (BOOL)isVenmoAppInstalled;


/**
 * Initiates Venmo OAuth request.
 * @param permissions List of permissions.
 * @param completionHandler Completion handler to call upon returning from OAuth flow.
 */
- (void)requestPermissions:(NSArray *)permissions withCompletionHandler:(VENOAuthCompletionHandler)handler;


/**
 * Returns a value indicating whether the access token should be refreshed.
 * @return YES if the session is open and the current date is later than the token's 
 * expiration date.
 */
- (BOOL)shouldRefreshToken;


/**
 * Attempts to refresh the session's access token.
 *
 * Access tokens expire after ~60 days, and can only be refreshed after they expire.
 * We recommend checking shouldRefreshToken in your application's
 * applicationDidBecomeActive: UIApplicationDelegate method. If shouldRefreshToken
 * returns YES, you should call refreshTokenWithCompletionHandler: to get a new token.
 *
 * @param completionHandler The handler block to execute.
 */
- (void)refreshTokenWithCompletionHandler:(VENRefreshTokenCompletionHandler)handler;


/**
 * Returns a value indicating whether the current session is valid.
 * @return YES if the session is open and has a non-expired token.
 */
- (BOOL)isSessionValid;


/**
 * Invalidates the current user session.
 *
 * Not that this method doesn't unauthorize the app.
 * To unauthorize an app, go to "Password & Authorizations" at https://venmo.com/account/settings/account
 */
- (void)logout;


/**
 * Sends a payment with the given parameters.
 * @param recipientHandle The recipient's phone number, email, Venmo username (app switch) or Venmo user ID (API)
 * @param amount The payment amount in cents
 * @param note A note for the payment
 * @param handler The handler block to execute after the payment succeeds or fails
 */
- (void)sendPaymentTo:(NSString *)recipientHandle
               amount:(NSUInteger)amount
                 note:(NSString *)note
    completionHandler:(VENTransactionCompletionHandler)handler;


/**
 * Sends a payment with the given parameters.
 * @param recipientHandle The recipient's phone number, email, Venmo username (app switch) or Venmo user ID (API)
 * @param amount The payment amount in cents
 * @param note A note for the payment
 * @param audience The audience for the payment
 * @param handler The handler block to execute after the payment succeeds or fails
 */
- (void)sendPaymentTo:(NSString *)recipientHandle
               amount:(NSUInteger)amount
                 note:(NSString *)note
             audience:(VENTransactionAudience)audience
    completionHandler:(VENTransactionCompletionHandler)handler;


/**
 * Sends a payment request with the given parameters.
 * @param recipientHandle The recipient's phone number, email, Venmo username (app switch) or Venmo user ID (API)
 * @param amount The requested amount in cents
 * @param note A note for the request
 * @param handler The handler block to execute after the request succeeds or fails
 */
- (void)sendRequestTo:(NSString *)recipientHandle
               amount:(NSUInteger)amount
                 note:(NSString *)note
    completionHandler:(VENTransactionCompletionHandler)handler;


/**
 * Sends a payment request with the given parameters.
 * @param recipientHandle The recipient's phone number, email, Venmo username (app switch) or Venmo user ID (API)
 * @param amount The requested amount in cents
 * @param note A note for the request
 * @param audience The audience for the payment
 * @param handler The handler block to execute after the request succeeds or fails
 */
- (void)sendRequestTo:(NSString *)recipientHandle
               amount:(NSUInteger)amount
                 note:(NSString *)note
             audience:(VENTransactionAudience)audience
    completionHandler:(VENTransactionCompletionHandler)handler;


@end