#include "handler.h"
#include "parser.h"
#include "utils.h"
#include <memory>
#import <Foundation/Foundation.h>

// Global state
Napi::ThreadSafeFunction tsfn;   // JS dispatcher
NSMutableDictionary<NSString*, id>* handlers; // suite+event → true

/** C → JS trampoline */
OSErr HandleAE(const AppleEvent* evt, AppleEvent* reply, void* refcon) {
    AEEventData aeData;
    
    // Get event class and ID from the Apple Event descriptor
    DescType eventClass, eventID;
    Size actualSize;
    
    OSErr err = AEGetAttributePtr(evt, keyEventClassAttr, typeType, 
                                  NULL, &eventClass, sizeof(eventClass), &actualSize);
    if (err == noErr) {
        aeData.suite = StringFromFourCharCode(eventClass);
    }
    
    err = AEGetAttributePtr(evt, keyEventIDAttr, typeType, 
                           NULL, &eventID, sizeof(eventID), &actualSize);
    if (err == noErr) {
        aeData.event = StringFromFourCharCode(eventID);
    }
    
    // Get transaction ID if present
    SInt32 transactionID;
    err = AEGetAttributePtr(evt, keyTransactionIDAttr, typeSInt32,
                           NULL, &transactionID, sizeof(transactionID), &actualSize);
    if (err == noErr) {
        aeData.transactionID = transactionID;
        aeData.hasTransaction = true;
    }
    
    // Parse target application info
    ParseTargetApplication(evt, aeData);
    
    // Parse parameters synchronously here where we have access to the Apple Event
    aeData.params = ParseAEParametersThreadSafe(evt);
    
    // Check if this event expects a reply
    // Simply check if reply is not NULL - the OS provides a reply descriptor when one is expected
    Boolean hasReply = (reply != NULL);
    
    // For events that expect a reply, we need to suspend the event and handle it asynchronously
    if (hasReply) {
        // Create a deep copy of the Apple Event for the suspended state
        AppleEvent eventCopy;
        err = AEDuplicateDesc(evt, &eventCopy);
        if (err != noErr) {
            return err;
        }
        
        // Create a deep copy of the reply descriptor
        AppleEvent replyCopy;
        err = AEDuplicateDesc(reply, &replyCopy);
        if (err != noErr) {
            AEDisposeDesc(&eventCopy);
            return err;
        }
        
        // Suspend the Apple Event (tell the system we'll reply later)
        err = AESuspendTheCurrentEvent(evt);
        if (err != noErr) {
            AEDisposeDesc(&eventCopy);
            AEDisposeDesc(&replyCopy);
            return err;
        }
        
        // Call JS dispatcher asynchronously with the suspended reply
        if (tsfn) {
            // RAII wrapper for callback data that works with raw pointers
            struct CallbackData {
                AEEventData payload;
                AppleEvent suspendedEvent;
                AppleEvent suspendedReply;
                
                CallbackData(const AEEventData& data, const AppleEvent& event, const AppleEvent& reply) 
                    : payload(data), suspendedEvent(event), suspendedReply(reply) {}
                
                ~CallbackData() {
                    // Clean up Apple Event descriptors
                    AEDisposeDesc(&suspendedEvent);
                    AEDisposeDesc(&suspendedReply);
                }
            };
            
            // Allocate on heap for async callback
            CallbackData* callbackData = new CallbackData(aeData, eventCopy, replyCopy);
            
            auto callback = [](Napi::Env env, Napi::Function jsDispatch, CallbackData* data) {
                if (!jsDispatch || !data) {
                    delete data; // Clean up if we can't proceed
                    return;
                }
                
                try {
                    Napi::Object aeObj = CreateAEEventObject(env, data->payload);
                    
                    // Create a proper done callback that handles the suspended reply
                    // The done callback takes ownership of the CallbackData and cleans it up
                    Napi::Function doneCallback = Napi::Function::New(env, 
                        [data](const Napi::CallbackInfo& info) -> Napi::Value {
                            // Use unique_ptr to ensure cleanup when done callback finishes
                            std::unique_ptr<CallbackData> dataPtr(data);
                            Napi::Env env = info.Env();
                            
                            if (!dataPtr) {
                                return env.Undefined();
                            }
                            
                            OSErr replyErr = noErr;
                            
                            try {
                                // Check if error was passed
                                if (info.Length() > 0 && !info[0].IsNull() && !info[0].IsUndefined()) {
                                    // Error case
                                    std::string errorMessage = info[0].ToString().Utf8Value();
                                    CFStringRef errorStr = CFStringCreateWithCString(NULL, errorMessage.c_str(), kCFStringEncodingUTF8);
                                    if (errorStr) {
                                        const char* cStr = CFStringGetCStringPtr(errorStr, kCFStringEncodingUTF8);
                                        if (cStr) {
                                            AEPutParamPtr(&dataPtr->suspendedReply, keyErrorString, typeUTF8Text, 
                                                        cStr, strlen(cStr));
                                        } else {
                                            // Fallback for when CFStringGetCStringPtr returns NULL
                                            CFIndex length = CFStringGetLength(errorStr);
                                            CFIndex maxSize = CFStringGetMaximumSizeForEncoding(length, kCFStringEncodingUTF8) + 1;
                                            char* buffer = new char[maxSize];
                                            if (CFStringGetCString(errorStr, buffer, maxSize, kCFStringEncodingUTF8)) {
                                                AEPutParamPtr(&dataPtr->suspendedReply, keyErrorString, typeUTF8Text, 
                                                            buffer, strlen(buffer));
                                            }
                                            delete[] buffer;
                                        }
                                        CFRelease(errorStr);
                                    }
                                    replyErr = errAEEventFailed;
                                } 
                                // Check if result was passed
                                else if (info.Length() > 1) {
                                    // Success case - put the result in the reply
                                    Napi::Value jsResult = info[1];
                                    if (jsResult.IsString()) {
                                        std::string strValue = jsResult.ToString().Utf8Value();
                                        AEPutParamPtr(&dataPtr->suspendedReply, keyDirectObject, typeUTF8Text, 
                                                    strValue.c_str(), strValue.length());
                                    } else if (jsResult.IsNumber()) {
                                        double numValue = jsResult.ToNumber().DoubleValue();
                                        if (numValue == floor(numValue)) {
                                            SInt32 intValue = static_cast<SInt32>(numValue);
                                            AEPutParamPtr(&dataPtr->suspendedReply, keyDirectObject, typeSInt32, 
                                                        &intValue, sizeof(intValue));
                                        } else {
                                            AEPutParamPtr(&dataPtr->suspendedReply, keyDirectObject, typeIEEE64BitFloatingPoint, 
                                                        &numValue, sizeof(numValue));
                                        }
                                    } else if (jsResult.IsBoolean()) {
                                        Boolean boolValue = jsResult.ToBoolean().Value();
                                        AEPutParamPtr(&dataPtr->suspendedReply, keyDirectObject, typeBoolean, 
                                                    &boolValue, sizeof(boolValue));
                                    } else if (jsResult.IsNull() || jsResult.IsUndefined()) {
                                        // Put null in reply
                                        AEPutParamPtr(&dataPtr->suspendedReply, keyDirectObject, typeNull, NULL, 0);
                                    }
                                }
                                
                                // Resume the suspended event with the reply
                                AEResumeTheCurrentEvent(&dataPtr->suspendedEvent, &dataPtr->suspendedReply, 
                                                       (AEEventHandlerUPP)kAENoDispatch, (SRefCon)(intptr_t)replyErr);
                            } catch (...) {
                                // If anything goes wrong, resume with error
                                AEResumeTheCurrentEvent(&dataPtr->suspendedEvent, &dataPtr->suspendedReply, 
                                                       (AEEventHandlerUPP)kAENoDispatch, (SRefCon)(intptr_t)errAEEventFailed);
                            }
                            
                            return env.Undefined();
                        });
                    
                    jsDispatch.Call({aeObj, doneCallback});
                } catch (...) {
                    // If JS call fails, resume with error and clean up
                    if (data) {
                        AEResumeTheCurrentEvent(&data->suspendedEvent, &data->suspendedReply, 
                                               (AEEventHandlerUPP)kAENoDispatch, (SRefCon)(intptr_t)errAEEventFailed);
                        delete data;
                    }
                }
            };
            
            napi_status status = tsfn.NonBlockingCall(callbackData, callback);
            
            if (status != napi_ok) {
                // Failed to call JS - resume with error and clean up
                AEResumeTheCurrentEvent(evt, reply, (AEEventHandlerUPP)kAENoDispatch, (SRefCon)(intptr_t)errAEEventFailed);
                delete callbackData;
                return errAEEventFailed;
            }
        }
        
        // Return special code to indicate we'll handle the reply later
        return errAEWaitCanceled;
    } else {
        // No reply expected - handle as before (fire and forget)
        if (tsfn) {
            auto callback = [](Napi::Env env, Napi::Function jsDispatch, AEEventData* payload) {
                // Use unique_ptr for automatic cleanup
                std::unique_ptr<AEEventData> payloadPtr(payload);
                
                if (jsDispatch && payloadPtr) {
                    try {
                        Napi::Object aeObj = CreateAEEventObject(env, *payloadPtr);
                        Napi::Function doneCallback = Napi::Function::New(env, [](const Napi::CallbackInfo& info) {
                            return info.Env().Undefined();
                        });
                        jsDispatch.Call({aeObj, doneCallback});
                    } catch (...) {
                        // Ignore JS errors for fire-and-forget events
                    }
                }
            };
            
            AEEventData* heapData = new AEEventData(aeData);
            
            napi_status status = tsfn.NonBlockingCall(heapData, callback);
            
            if (status != napi_ok) {
                delete heapData;
            }
        }
        
        return noErr;
    }
}

/** JS tells native: "start listening for (suite,event)" */
Napi::Value addHandler(const Napi::CallbackInfo& info) {
    Napi::Env env = info.Env();
    
    if (info.Length() < 2 || !info[0].IsString() || !info[1].IsString()) {
        Napi::TypeError::New(env, "Expected two string arguments").ThrowAsJavaScriptException();
        return env.Undefined();
    }
    
    std::string suite = info[0].As<Napi::String>().Utf8Value();
    std::string event = info[1].As<Napi::String>().Utf8Value();
    
    NSString* key = [NSString stringWithFormat:@"%s%s", suite.c_str(), event.c_str()];
    
    if (!handlers[key]) {
        OSType suiteCode = FourCharCodeFromString(suite);
        OSType eventCode = FourCharCodeFromString(event);
        
        OSErr err = AEInstallEventHandler(suiteCode, eventCode, 
                                         NewAEEventHandlerUPP(HandleAE), 
                                         0, false);
        
        if (err == noErr) {
            handlers[key] = @YES;
        } else {
            Napi::Error::New(env, "Failed to install Apple Event handler").ThrowAsJavaScriptException();
            return env.Undefined();
        }
    }
    
    return env.Undefined();
}

/** Set the JavaScript dispatch function */
Napi::Value setDispatch(const Napi::CallbackInfo& info) {
    Napi::Env env = info.Env();
    
    if (info.Length() < 1 || !info[0].IsFunction()) {
        Napi::TypeError::New(env, "Expected a function argument").ThrowAsJavaScriptException();
        return env.Undefined();
    }
    
    Napi::Function jsDispatch = info[0].As<Napi::Function>();
    
    // Update the thread-safe function with the actual dispatch function
    tsfn = Napi::ThreadSafeFunction::New(
        env,
        jsDispatch,
        "osa_dispatch",
        0,  // unlimited queue
        1   // single thread
    );
    
    return env.Undefined();
}