Initial commit

extension-iap/src/iap_ios.mm

@@ -0,0 +1,806 @@
+#if defined(DM_PLATFORM_IOS)
+
+#include <dmsdk/sdk.h>
+
+#include "iap.h"
+#include "iap_private.h"
+
+#import <Foundation/Foundation.h>
+#import <UIKit/UIKit.h>
+#import <StoreKit/StoreKit.h>
+
+#define LIB_NAME "iap"
+
+struct IAP;
+
+@interface SKPaymentTransactionObserver : NSObject<SKPaymentTransactionObserver>
+    @property IAP* m_IAP;
+@end
+
+/*# In-app purchases API documentation
+ *
+ * Functions and constants for interacting with Apple's In-app purchases
+ * and Google's In-app billing.
+ *
+ * @document
+ * @name In-app purchases
+ * @namespace iap
+ */
+
+struct IAP
+{
+    IAP()
+    {
+        m_Callback = LUA_NOREF;
+        m_Self = LUA_NOREF;
+        m_InitCount = 0;
+        m_AutoFinishTransactions = true;
+        m_PendingTransactions = 0;
+  }
+    int                  m_InitCount;
+    int                  m_Callback;
+    int                  m_Self;
+    bool                 m_AutoFinishTransactions;
+    NSMutableDictionary* m_PendingTransactions;
+    IAPListener          m_Listener;
+    SKPaymentTransactionObserver* m_Observer;
+};
+
+IAP g_IAP;
+
+
+
+@interface SKProductsRequestDelegate : NSObject<SKProductsRequestDelegate>
+    @property lua_State* m_LuaState;
+    @property (assign) SKProductsRequest* m_Request;
+@end
+
+@implementation SKProductsRequestDelegate
+- (void)productsRequest:(SKProductsRequest *)request didReceiveResponse:(SKProductsResponse *)response{
+
+    lua_State* L = self.m_LuaState;
+    if (g_IAP.m_Callback == LUA_NOREF) {
+        dmLogError("No callback set");
+        return;
+    }
+
+    NSArray * skProducts = response.products;
+    int top = lua_gettop(L);
+
+    lua_rawgeti(L, LUA_REGISTRYINDEX, g_IAP.m_Callback);
+
+    // Setup self
+    lua_rawgeti(L, LUA_REGISTRYINDEX, g_IAP.m_Self);
+    lua_pushvalue(L, -1);
+    dmScript::SetInstance(L);
+
+    if (!dmScript::IsInstanceValid(L))
+    {
+        dmLogError("Could not run facebook callback because the instance has been deleted.");
+        lua_pop(L, 2);
+        assert(top == lua_gettop(L));
+        return;
+    }
+
+    lua_newtable(L);
+    for (SKProduct * p in skProducts) {
+
+        lua_pushstring(L, [p.productIdentifier UTF8String]);
+        lua_newtable(L);
+
+        lua_pushstring(L, "ident");
+        lua_pushstring(L, [p.productIdentifier UTF8String]);
+        lua_rawset(L, -3);
+
+        lua_pushstring(L, "title");
+        lua_pushstring(L, [p.localizedTitle UTF8String]);
+        lua_rawset(L, -3);
+
+        lua_pushstring(L, "description");
+        lua_pushstring(L, [p.localizedDescription  UTF8String]);
+        lua_rawset(L, -3);
+
+        lua_pushstring(L, "price");
+        lua_pushnumber(L, p.price.floatValue);
+        lua_rawset(L, -3);
+
+        NSNumberFormatter *formatter = [[[NSNumberFormatter alloc] init] autorelease];
+        [formatter setNumberStyle: NSNumberFormatterCurrencyStyle];
+        [formatter setLocale: p.priceLocale];
+        NSString *price_string = [formatter stringFromNumber: p.price];
+
+        lua_pushstring(L, "price_string");
+        lua_pushstring(L, [price_string UTF8String]);
+        lua_rawset(L, -3);
+
+        lua_pushstring(L, "currency_code");
+        lua_pushstring(L, [[p.priceLocale objectForKey:NSLocaleCurrencyCode] UTF8String]);
+        lua_rawset(L, -3);
+
+        lua_rawset(L, -3);
+    }
+    lua_pushnil(L);
+
+    int ret = lua_pcall(L, 3, 0, 0);
+    if (ret != 0) {
+        dmLogError("Error running iap callback");
+        lua_pop(L, 1);
+    }
+
+    dmScript::Unref(L, LUA_REGISTRYINDEX, g_IAP.m_Callback);
+    dmScript::Unref(L, LUA_REGISTRYINDEX, g_IAP.m_Self);
+    g_IAP.m_Callback = LUA_NOREF;
+    g_IAP.m_Self = LUA_NOREF;
+
+    assert(top == lua_gettop(L));
+}
+
+- (void)request:(SKRequest *)request didFailWithError:(NSError *)error{
+    dmLogWarning("SKProductsRequest failed: %s", [error.localizedDescription UTF8String]);
+
+    lua_State* L = self.m_LuaState;
+    int top = lua_gettop(L);
+
+    if (g_IAP.m_Callback == LUA_NOREF) {
+        dmLogError("No callback set");
+        return;
+    }
+
+    lua_rawgeti(L, LUA_REGISTRYINDEX, g_IAP.m_Callback);
+
+    // Setup self
+    lua_rawgeti(L, LUA_REGISTRYINDEX, g_IAP.m_Self);
+    lua_pushvalue(L, -1);
+    dmScript::SetInstance(L);
+
+    if (!dmScript::IsInstanceValid(L))
+    {
+        dmLogError("Could not run iap callback because the instance has been deleted.");
+        lua_pop(L, 2);
+        assert(top == lua_gettop(L));
+        return;
+    }
+
+    lua_pushnil(L);
+    IAP_PushError(L, [error.localizedDescription UTF8String], REASON_UNSPECIFIED);
+
+    int ret = lua_pcall(L, 3, 0, 0);
+    if (ret != 0) {
+        dmLogError("Error running iap callback");
+        lua_pop(L, 1);
+    }
+
+    dmScript::Unref(L, LUA_REGISTRYINDEX, g_IAP.m_Callback);
+    dmScript::Unref(L, LUA_REGISTRYINDEX, g_IAP.m_Self);
+    g_IAP.m_Callback = LUA_NOREF;
+    g_IAP.m_Self = LUA_NOREF;
+
+    assert(top == lua_gettop(L));
+}
+
+- (void)requestDidFinish:(SKRequest *)request
+{
+    [self.m_Request release];
+    [self release];
+}
+
+@end
+
+static void PushTransaction(lua_State* L, SKPaymentTransaction* transaction)
+{
+    lua_newtable(L);
+
+    lua_pushstring(L, "ident");
+    lua_pushstring(L, [transaction.payment.productIdentifier UTF8String]);
+    lua_rawset(L, -3);
+
+    lua_pushstring(L, "state");
+    lua_pushnumber(L, transaction.transactionState);
+    lua_rawset(L, -3);
+
+    if (transaction.transactionState == SKPaymentTransactionStatePurchased || transaction.transactionState == SKPaymentTransactionStateRestored) {
+        lua_pushstring(L, "trans_ident");
+        lua_pushstring(L, [transaction.transactionIdentifier UTF8String]);
+        lua_rawset(L, -3);
+    }
+
+    if (transaction.transactionState == SKPaymentTransactionStatePurchased) {
+        lua_pushstring(L, "receipt");
+        if (floor(NSFoundationVersionNumber) <= NSFoundationVersionNumber_iOS_6_1) {
+            lua_pushlstring(L, (const char*) transaction.transactionReceipt.bytes, transaction.transactionReceipt.length);
+        } else {
+            NSURL *receiptURL = [[NSBundle mainBundle] appStoreReceiptURL];
+            NSData *receiptData = [NSData dataWithContentsOfURL:receiptURL];
+            lua_pushlstring(L, (const char*) receiptData.bytes, receiptData.length);
+        }
+        lua_rawset(L, -3);
+    }
+
+    NSDateFormatter *dateFormatter = [[[NSDateFormatter alloc] init] autorelease];
+    [dateFormatter setDateFormat:@"yyyy-MM-dd'T'HH:mm:ssZZZ"];
+    lua_pushstring(L, "date");
+    lua_pushstring(L, [[dateFormatter stringFromDate: transaction.transactionDate] UTF8String]);
+    lua_rawset(L, -3);
+
+    if (transaction.transactionState == SKPaymentTransactionStateRestored && transaction.originalTransaction) {
+        lua_pushstring(L, "original_trans");
+        PushTransaction(L, transaction.originalTransaction);
+        lua_rawset(L, -3);
+    }
+}
+
+void RunTransactionCallback(lua_State* L, int cb, int self, SKPaymentTransaction* transaction)
+{
+    int top = lua_gettop(L);
+
+    lua_rawgeti(L, LUA_REGISTRYINDEX, cb);
+
+    // Setup self
+    lua_rawgeti(L, LUA_REGISTRYINDEX, self);
+    lua_pushvalue(L, -1);
+    dmScript::SetInstance(L);
+
+    if (!dmScript::IsInstanceValid(L))
+    {
+        dmLogError("Could not run iap callback because the instance has been deleted.");
+        lua_pop(L, 2);
+        assert(top == lua_gettop(L));
+        return;
+    }
+
+    PushTransaction(L, transaction);
+
+    if (transaction.transactionState == SKPaymentTransactionStateFailed) {
+        if (transaction.error.code == SKErrorPaymentCancelled) {
+            IAP_PushError(L, [transaction.error.localizedDescription UTF8String], REASON_USER_CANCELED);
+        } else {
+            IAP_PushError(L, [transaction.error.localizedDescription UTF8String], REASON_UNSPECIFIED);
+        }
+    } else {
+        lua_pushnil(L);
+    }
+
+    int ret = lua_pcall(L, 3, 0, 0);
+    if (ret != 0) {
+        dmLogError("Error running iap callback");
+        lua_pop(L, 1);
+    }
+
+    assert(top == lua_gettop(L));
+}
+
+@implementation SKPaymentTransactionObserver
+    - (void)paymentQueue:(SKPaymentQueue *)queue updatedTransactions:(NSArray *)transactions
+    {
+        for (SKPaymentTransaction * transaction in transactions) {
+
+            if ((!g_IAP.m_AutoFinishTransactions) && (transaction.transactionState == SKPaymentTransactionStatePurchased)) {
+                NSData *data = [transaction.transactionIdentifier dataUsingEncoding:NSUTF8StringEncoding];
+                uint64_t trans_id_hash = dmHashBuffer64((const char*) [data bytes], [data length]);
+                [g_IAP.m_PendingTransactions setObject:transaction forKey:[NSNumber numberWithInteger:trans_id_hash] ];
+            }
+
+            bool has_listener = false;
+            if (self.m_IAP->m_Listener.m_Callback != LUA_NOREF) {
+                const IAPListener& l = self.m_IAP->m_Listener;
+                RunTransactionCallback(l.m_L, l.m_Callback, l.m_Self, transaction);
+                has_listener = true;
+            }
+
+            switch (transaction.transactionState)
+            {
+                case SKPaymentTransactionStatePurchasing:
+                    break;
+                case SKPaymentTransactionStatePurchased:
+                    if (has_listener > 0 && g_IAP.m_AutoFinishTransactions) {
+                        [[SKPaymentQueue defaultQueue] finishTransaction:transaction];
+                    }
+                    break;
+                case SKPaymentTransactionStateFailed:
+                    if (has_listener > 0) {
+                        [[SKPaymentQueue defaultQueue] finishTransaction:transaction];
+                    }
+                    break;
+                case SKPaymentTransactionStateRestored:
+                    if (has_listener > 0) {
+                        [[SKPaymentQueue defaultQueue] finishTransaction:transaction];
+                    }
+                    break;
+            }
+        }
+    }
+@end
+
+/*# list in-app products
+ *
+ * Get a list of all avaliable iap products. Products are described as a [type:table]
+ * with the following fields:
+ *
+ * `ident`
+ * : The product identifier.
+ *
+ * `title`
+ * : The product title.
+ *
+ * `description`
+ * : The product description.
+ *
+ * `price`
+ * : The price of the product.
+ *
+ * `price_string`
+ * : The price of the product, as a formatted string (amount and currency symbol).
+ *
+ * `currency_code` [icon:ios] [icon:googleplay] [icon:facebook]
+ * : The currency code. On Google Play, this reflects the merchant's locale, instead of the user's.
+ *
+ * [icon:attention] Nested calls, that is calling `iap.list()` from within the callback is
+ * not supported. Doing so will result in call being ignored with the engine reporting
+ * "Unexpected callback set".
+ *
+ * @name iap.list
+ * @param ids [type:table] table (array) of identifiers to get products from
+ * @param callback [type:function(self, products, error)] result callback
+ *
+ * `self`
+ * : [type:object] The current object.
+ *
+ * `products`
+ * : [type:table] Table describing the available iap products. See above for details.
+ *
+ * `error`
+ * : [type:table] a table containing error information. `nil` if there is no error.
+ * - `error` (the error message)
+ *
+ * @examples
+ *
+ * ```lua
+ * local function iap_callback(self, products, error)
+ *   if error == nil then
+ *     for k,p in pairs(products) do
+ *       -- present the product
+ *       print(p.title)
+ *       print(p.description)
+ *     end
+ *   else
+ *     print(error.error)
+ *   end
+ * end
+ *
+ * function init(self)
+ *     iap.list({"my_iap"}, iap_callback)
+ * end
+ * ```
+ */
+int IAP_List(lua_State* L)
+{
+    int top = lua_gettop(L);
+    if (g_IAP.m_Callback != LUA_NOREF) {
+        dmLogError("Unexpected callback set");
+        dmScript::Unref(L, LUA_REGISTRYINDEX, g_IAP.m_Callback);
+        dmScript::Unref(L, LUA_REGISTRYINDEX, g_IAP.m_Self);
+        g_IAP.m_Callback = LUA_NOREF;
+        g_IAP.m_Self = LUA_NOREF;
+    }
+
+    NSCountedSet* product_identifiers = [[[NSCountedSet alloc] init] autorelease];
+
+    luaL_checktype(L, 1, LUA_TTABLE);
+    lua_pushnil(L);
+    while (lua_next(L, 1) != 0) {
+        const char* p = luaL_checkstring(L, -1);
+        [product_identifiers addObject: [NSString stringWithUTF8String: p]];
+        lua_pop(L, 1);
+    }
+
+    luaL_checktype(L, 2, LUA_TFUNCTION);
+    lua_pushvalue(L, 2);
+    g_IAP.m_Callback = dmScript::Ref(L, LUA_REGISTRYINDEX);
+
+    dmScript::GetInstance(L);
+    g_IAP.m_Self = dmScript::Ref(L, LUA_REGISTRYINDEX);
+
+    SKProductsRequest* products_request = [[SKProductsRequest alloc] initWithProductIdentifiers: product_identifiers];
+    SKProductsRequestDelegate* delegate = [SKProductsRequestDelegate alloc];
+    delegate.m_LuaState = dmScript::GetMainThread(L);
+    delegate.m_Request = products_request;
+    products_request.delegate = delegate;
+    [products_request start];
+
+    assert(top == lua_gettop(L));
+    return 0;
+}
+
+/*# buy product
+ *
+ * Perform a product purchase.
+ *
+ * [icon:attention] Calling `iap.finish()` is required on a successful transaction if
+ * `auto_finish_transactions` is disabled in project settings.
+ *
+ * @name iap.buy
+ * @param id [type:string] product to buy
+ * @param [options] [type:table] optional parameters as properties. The following parameters can be set:
+ *
+ * - `request_id` ([icon:facebook] Facebook only. Optional custom unique request id to
+ * set for this transaction. The id becomes attached to the payment within the Graph API.)
+ *
+ * @examples
+ *
+ * ```lua
+ * local function iap_listener(self, transaction, error)
+ *   if error == nil then
+ *     -- purchase is successful.
+ *     print(transaction.date)
+ *     -- required if auto finish transactions is disabled in project settings
+ *     if (transaction.state == iap.TRANS_STATE_PURCHASED) then
+ *       -- do server-side verification of purchase here..
+ *       iap.finish(transaction)
+ *     end
+ *   else
+ *     print(error.error, error.reason)
+ *   end
+ * end
+ *
+ * function init(self)
+ *     iap.set_listener(iap_listener)
+ *     iap.buy("my_iap")
+ * end
+ * ```
+ */
+int IAP_Buy(lua_State* L)
+{
+    int top = lua_gettop(L);
+
+    const char* id = luaL_checkstring(L, 1);
+    SKMutablePayment* payment = [[SKMutablePayment alloc] init];
+    payment.productIdentifier = [NSString stringWithUTF8String: id];
+    payment.quantity = 1;
+
+    [[SKPaymentQueue defaultQueue] addPayment:payment];
+    [payment release];
+
+    assert(top == lua_gettop(L));
+    return 0;
+}
+
+/*# finish buying product
+ *
+ * Explicitly finish a product transaction.
+ *
+ * [icon:attention] Calling iap.finish is required on a successful transaction
+ * if `auto_finish_transactions` is disabled in project settings. Calling this function
+ * with `auto_finish_transactions` set will be ignored and a warning is printed.
+ * The `transaction.state` field must equal `iap.TRANS_STATE_PURCHASED`.
+ *
+ * @name iap.finish
+ * @param transaction [type:table] transaction table parameter as supplied in listener callback
+ *
+ */
+int IAP_Finish(lua_State* L)
+{
+    if(g_IAP.m_AutoFinishTransactions)
+    {
+        dmLogWarning("Calling iap.finish when autofinish transactions is enabled. Ignored.");
+        return 0;
+    }
+
+    int top = lua_gettop(L);
+
+    luaL_checktype(L, 1, LUA_TTABLE);
+
+    lua_getfield(L, -1, "state");
+    if (lua_isnumber(L, -1))
+    {
+        if(lua_tointeger(L, -1) != SKPaymentTransactionStatePurchased)
+        {
+            dmLogError("Transaction error. Invalid transaction state for transaction finish (must be iap.TRANS_STATE_PURCHASED).");
+            lua_pop(L, 1);
+            assert(top == lua_gettop(L));
+            return 0;
+        }
+    }
+    lua_pop(L, 1);
+
+    lua_getfield(L, -1, "trans_ident");
+    if (!lua_isstring(L, -1)) {
+        dmLogError("Transaction error. Invalid transaction data for transaction finish, does not contain 'trans_ident' key.");
+        lua_pop(L, 1);
+    }
+    else
+    {
+          const char *str = lua_tostring(L, -1);
+          uint64_t trans_ident_hash = dmHashBuffer64(str, strlen(str));
+          lua_pop(L, 1);
+          SKPaymentTransaction * transaction = [g_IAP.m_PendingTransactions objectForKey:[NSNumber numberWithInteger:trans_ident_hash]];
+          if(transaction == 0x0) {
+              dmLogError("Transaction error. Invalid trans_ident value for transaction finish.");
+          } else {
+              [[SKPaymentQueue defaultQueue] finishTransaction:transaction];
+              [g_IAP.m_PendingTransactions removeObjectForKey:[NSNumber numberWithInteger:trans_ident_hash]];
+          }
+    }
+
+    assert(top == lua_gettop(L));
+    return 0;
+}
+
+/*# restore products (non-consumable)
+ *
+ * Restore previously purchased products.
+ *
+ * @name iap.restore
+ * @return success [type:boolean] `true` if current store supports handling
+ * restored transactions, otherwise `false`.
+ */
+int IAP_Restore(lua_State* L)
+{
+    // TODO: Missing callback here for completion/error
+    // See callback under "Handling Restored Transactions"
+    // https://developer.apple.com/library/ios/documentation/StoreKit/Reference/SKPaymentTransactionObserver_Protocol/Reference/Reference.html
+    int top = lua_gettop(L);
+    [[SKPaymentQueue defaultQueue] restoreCompletedTransactions];
+    assert(top == lua_gettop(L));
+    lua_pushboolean(L, 1);
+    return 1;
+}
+
+/*# set purchase transaction listener
+ *
+ * Set the callback function to receive purchase transaction events. Transactions are
+ * described as a [type:table] with the following fields:
+ *
+ * `ident`
+ * : The product identifier.
+ *
+ * `state`
+ * : The transaction state. See `iap.TRANS_STATE_*`.
+ *
+ * `date`
+ * : The date and time for the transaction.
+ *
+ * `trans_ident`
+ * : The transaction identifier. This field is only set when `state` is TRANS_STATE_RESTORED,
+ * TRANS_STATE_UNVERIFIED or TRANS_STATE_PURCHASED.
+ *
+ * `receipt`
+ * : The transaction receipt. This field is only set when `state` is TRANS_STATE_PURCHASED
+ * or TRANS_STATE_UNVERIFIED.
+ *
+ * `original_trans` [icon:apple]
+ * : Apple only. The original transaction. This field is only set when `state` is
+ * TRANS_STATE_RESTORED.
+ *
+ * `signature` [icon:googleplay]
+ * : Google Play only. A string containing the signature of the purchase data that was signed
+ * with the private key of the developer.
+ *
+ * `request_id` [icon:facebook]
+ * : Facebook only. This field is set to the optional custom unique request id `request_id`
+ * if set in the `iap.buy()` call parameters.
+ *
+ * `user_id` [icon:amazon]
+ * : Amazon Pay only. The user ID.
+ *
+ * `is_sandbox_mode` [icon:amazon]
+ * : Amazon Pay only. If `true`, the SDK is running in Sandbox mode. This only allows
+ * interactions with the Amazon AppTester. Use this mode only for testing locally.
+ *
+ * `cancel_date` [icon:amazon]
+ * : Amazon Pay only. The cancel date for the purchase. This field is only set if the
+ * purchase is canceled.
+ *
+ * `canceled` [icon:amazon]
+ * : Amazon Pay only. Is set to `true` if the receipt was canceled or has expired;
+ * otherwise `false`.
+ *
+ * @name iap.set_listener
+ * @param listener [type:function(self, transaction, error)] listener callback function.
+ * Pass an empty function if you no longer wish to receive callbacks.
+ *
+ * `self`
+ * : [type:object] The current object.
+ *
+ * `transaction`
+ * : [type:table] a table describing the transaction. See above for details.
+ *
+ * `error`
+ * : [type:table] a table containing error information. `nil` if there is no error.
+ * - `error` (the error message)
+ * - `reason` (the reason for the error, see `iap.REASON_*`)
+ *
+ */
+int IAP_SetListener(lua_State* L)
+{
+    IAP* iap = &g_IAP;
+    luaL_checktype(L, 1, LUA_TFUNCTION);
+    lua_pushvalue(L, 1);
+    int cb = dmScript::Ref(L, LUA_REGISTRYINDEX);
+
+    if (iap->m_Listener.m_Callback != LUA_NOREF) {
+        dmScript::Unref(iap->m_Listener.m_L, LUA_REGISTRYINDEX, iap->m_Listener.m_Callback);
+        dmScript::Unref(iap->m_Listener.m_L, LUA_REGISTRYINDEX, iap->m_Listener.m_Self);
+    }
+
+    iap->m_Listener.m_L = dmScript::GetMainThread(L);
+    iap->m_Listener.m_Callback = cb;
+
+    dmScript::GetInstance(L);
+    iap->m_Listener.m_Self = dmScript::Ref(L, LUA_REGISTRYINDEX);
+
+    if (g_IAP.m_Observer == 0) {
+        SKPaymentTransactionObserver* observer = [[SKPaymentTransactionObserver alloc] init];
+        observer.m_IAP = &g_IAP;
+        // NOTE: We add the listener *after* a lua listener is set
+        // The payment queue is persistent and "old" transaction might be processed
+        // from previous session. We call "finishTransaction" when appropriate
+        // for all transaction and we must ensure that the result is delivered to lua.
+        [[SKPaymentQueue defaultQueue] addTransactionObserver: observer];
+        g_IAP.m_Observer = observer;
+    }
+
+    return 0;
+}
+
+/*# get current provider id
+ *
+ * @name iap.get_provider_id
+ * @return id [type:constant] provider id.
+ *
+ * - `iap.PROVIDER_ID_GOOGLE`
+ * - `iap.PROVIDER_ID_AMAZON`
+ * - `iap.PROVIDER_ID_APPLE`
+ * - `iap.PROVIDER_ID_FACEBOOK`
+ *
+ */
+int IAP_GetProviderId(lua_State* L)
+{
+    lua_pushinteger(L, PROVIDER_ID_APPLE);
+    return 1;
+}
+
+static const luaL_reg IAP_methods[] =
+{
+    {"list", IAP_List},
+    {"buy", IAP_Buy},
+    {"finish", IAP_Finish},
+    {"restore", IAP_Restore},
+    {"set_listener", IAP_SetListener},
+    {"get_provider_id", IAP_GetProviderId},
+    {0, 0}
+};
+
+/*# transaction purchasing state
+ *
+ * This is an intermediate mode followed by TRANS_STATE_PURCHASED.
+ * Store provider support dependent.
+ *
+ * @name iap.TRANS_STATE_PURCHASING
+ * @variable
+ */
+
+/*# transaction purchased state
+ *
+ * @name iap.TRANS_STATE_PURCHASED
+ * @variable
+ */
+
+/*# transaction unverified state, requires verification of purchase
+ *
+ * @name iap.TRANS_STATE_UNVERIFIED
+ * @variable
+ */
+
+/*# transaction failed state
+ *
+ * @name iap.TRANS_STATE_FAILED
+ * @variable
+ */
+
+/*# transaction restored state
+ *
+ * This is only available on store providers supporting restoring purchases.
+ *
+ * @name iap.TRANS_STATE_RESTORED
+ * @variable
+ */
+
+/*# unspecified error reason
+ *
+ * @name iap.REASON_UNSPECIFIED
+ * @variable
+ */
+
+/*# user canceled reason
+ *
+ * @name iap.REASON_USER_CANCELED
+ * @variable
+ */
+
+
+/*# iap provider id for Google
+ *
+ * @name iap.PROVIDER_ID_GOOGLE
+ * @variable
+ */
+
+/*# provider id for Amazon
+ *
+ * @name iap.PROVIDER_ID_AMAZON
+ * @variable
+ */
+
+/*# provider id for Apple
+ *
+ * @name iap.PROVIDER_ID_APPLE
+ * @variable
+ */
+
+/*# provider id for Facebook
+ *
+ * @name iap.PROVIDER_ID_FACEBOOK
+ * @variable
+ */
+
+dmExtension::Result InitializeIAP(dmExtension::Params* params)
+{
+    // TODO: Life-cycle managaemnt is *budget*. No notion of "static initalization"
+    // Extend extension functionality with per system initalization?
+    if (g_IAP.m_InitCount == 0) {
+        g_IAP.m_AutoFinishTransactions = dmConfigFile::GetInt(params->m_ConfigFile, "iap.auto_finish_transactions", 1) == 1;
+        g_IAP.m_PendingTransactions = [[NSMutableDictionary alloc]initWithCapacity:2];
+    }
+    g_IAP.m_InitCount++;
+
+
+    lua_State*L = params->m_L;
+    int top = lua_gettop(L);
+    luaL_register(L, LIB_NAME, IAP_methods);
+
+    // ensure ios payment constants values corresponds to iap constants.
+    assert(TRANS_STATE_PURCHASING == SKPaymentTransactionStatePurchasing);
+    assert(TRANS_STATE_PURCHASED == SKPaymentTransactionStatePurchased);
+    assert(TRANS_STATE_FAILED == SKPaymentTransactionStateFailed);
+    assert(TRANS_STATE_RESTORED == SKPaymentTransactionStateRestored);
+
+    IAP_PushConstants(L);
+
+    lua_pop(L, 1);
+    assert(top == lua_gettop(L));
+
+    return dmExtension::RESULT_OK;
+}
+
+dmExtension::Result FinalizeIAP(dmExtension::Params* params)
+{
+    --g_IAP.m_InitCount;
+
+    // TODO: Should we support one listener per lua-state?
+    // Or just use a single lua-state...?
+    if (params->m_L == g_IAP.m_Listener.m_L && g_IAP.m_Listener.m_Callback != LUA_NOREF) {
+        dmScript::Unref(g_IAP.m_Listener.m_L, LUA_REGISTRYINDEX, g_IAP.m_Listener.m_Callback);
+        dmScript::Unref(g_IAP.m_Listener.m_L, LUA_REGISTRYINDEX, g_IAP.m_Listener.m_Self);
+        g_IAP.m_Listener.m_L = 0;
+        g_IAP.m_Listener.m_Callback = LUA_NOREF;
+        g_IAP.m_Listener.m_Self = LUA_NOREF;
+    }
+
+    if (g_IAP.m_InitCount == 0) {
+        if (g_IAP.m_PendingTransactions) {
+             [g_IAP.m_PendingTransactions release];
+             g_IAP.m_PendingTransactions = 0;
+        }
+
+        if (g_IAP.m_Observer) {
+            [[SKPaymentQueue defaultQueue] removeTransactionObserver: g_IAP.m_Observer];
+            [g_IAP.m_Observer release];
+            g_IAP.m_Observer = 0;
+        }
+    }
+    return dmExtension::RESULT_OK;
+}
+
+
+DM_DECLARE_EXTENSION(IAPExt, "IAP", 0, 0, InitializeIAP, 0, 0, FinalizeIAP)
+
+#endif // DM_PLATFORM_IOS