#include "configops.h"
#include "metadataops.h"
#include "StandardConstants.h"
#include "simulator.h"
#include <pthread.h>

/*
Name: addProcess
Process: allocates the memory for the pcb, grabs the data from the created PCB, 
         dumps the data so that the node can be linked correctly. 
Function Input/Parameters: source PCB (ProcessControlBlock)
Function Output/Parameters: none
Function Output/Returned: filled PCB (ProcessControlBlock *)
Device Input/Device: none
Device Output/Device: none
Dependencies: malloc, sizeof, ???
*/
ProcessControlBlock *addProcess(const ProcessControlBlock source)
{
    ProcessControlBlock *workingNode;
    workingNode = malloc(sizeof(ProcessControlBlock));
    workingNode->uniquePid = source.uniquePid;
    workingNode->cpuCycles = source.cpuCycles;
    workingNode->ioCycles = source.ioCycles;
    workingNode->nextOpCode = source.nextOpCode;
    workingNode->process_state = source.process_state;
    workingNode->timeLeft = source.timeLeft;
    workingNode->totalCycles = source.totalCycles;
    workingNode->nextPtr = NULL;
    // return workingNode
    return workingNode;
}

/*
Name: createProcessList
Process: reads through the opcode struct to fill out the linked list of PCBs
Function Input/Parameters: none
Function Output/Parameters: none
Function Output/Returned: head pointer to the PCBs
Device Input/Device: none
Device Output/Device: none
Dependencies: malloc, sizeof, ???
*/
ProcessControlBlockLL *createProcessList()
{
    // allocate and create the ProcessControlBlockLL using malloc and size of
    ProcessControlBlockLL *headBlock;
    headBlock = malloc(sizeof(ProcessControlBlockLL));
    // set the head pointer to NULL
    headBlock->headPtr = NULL;
    // return headBlock
    return headBlock;
}

/*
Name: destroyProcessList
Process: deallocates memory used for the linked list struct
Function Input/Parameters: head pointer to linked list (ProcessControlBlockLL *)
Function Output/Parameters: none
Function Output/Returned: NULL
Device Input/Device: none
Device Output/Device: none
Dependencies: free, destroyProcessListHelper, ???
*/
ProcessControlBlockLL *destroyProcessList(ProcessControlBlockLL *linkedListPtr)
{
    // call the first destroyProcessListHelper
    destroyProcessListHelper(linkedListPtr->headPtr);
    // free the rest of the struct
    free(linkedListPtr);
    // return null
    return NULL;
}

/*
Name: destroyProcessListHelper
Process: recursively clears the PCB linked list struct, freeing the struct
Function Input/Parameters: head pointer to linked list (ProcessControlBlockLL *)
Function Output/Parameters: none
Function Output/Returned: NULL
Device Input/Device: none
Device Output/Device: none
Dependencies: free, destroyProcessListHelper(recursively), ???
*/
ProcessControlBlock *destroyProcessListHelper(ProcessControlBlock *nodePtr)
{
    // check to see if the pointer is NOT null
    if(nodePtr != NULL)
    {
        // if not null, move to the next pointer (recurse)
        nodePtr->nextPtr = destroyProcessListHelper(nodePtr->nextPtr);
    }
    // free the 'parent' node
    free(nodePtr);
    // return null
    return NULL;
}

/*
Name: fillProcessList
Process: iterates through the metadata LL, fills out each process as needed.
Function Input/Parameters: metadata (OpCodeType *),
                           headPointer (ProcessControlBlockLL *)
Function Output/Parameters: none
Function Output/Returned: pointer to filled PCB (ProcessControlBlockLL *)
Device Input/Device: none
Device Output/Device: none
Dependencies: ???
*/
ProcessControlBlockLL *fillProcessList(OpCodeType *metadataPtr, ProcessControlBlockLL *headPointer)
{
    // initialize function/variables
        // need a working pointer for the metadata
    OpCodeType *wkgMetaPtr;
    ProcessControlBlock currentPCB;
    ProcessControlBlock *wkgPCBPtr;
        // need a variable to count how many IO cycles are in the process
    int ioCycleCount = 0;
        // need a variable to count how many CPU cycles are in the process
    int cpuCycleCount = 0;
        // need a variable to calculate the time left in ms for a process
    double timeLeftCount = 0.0;
        // need a variable that fills PIDs, starting at 0
    int processId = 0;
        // process variables?
    char *command;
    char *argument;
    char *inOutArg;
    int integerArgumentOne;
    // unused as of current
    //int integerArgumentTwo;

    // set the working pointer to the first part of the metadata pointer
    wkgMetaPtr = metadataPtr;
    // set another working pointer to the first part of the PCB list
    wkgPCBPtr = headPointer->headPtr;

    // grab the first command and argument
    command = wkgMetaPtr->command;
    argument = wkgMetaPtr->strArg1;
    inOutArg = wkgMetaPtr->inOutArg;
    
    // integer argument two is unused atm
    //integerArgumentTwo = wkgMetaPtr->intArg3;

    // loop through the process list, until you hit a sys end.
    while(wkgMetaPtr->nextNode != NULL && !(compareString(argument, "end") == 0 && compareString(command, "sys") == 0))
    {
        integerArgumentOne = wkgMetaPtr->intArg2;
        // printf("%s command, %s argument, %d\n", command, argument, integerArgumentOne);
        // if app start,
        if (compareString(command, "app") && compareString(argument, "start"))
        {
            // set the unique ID for both PCB and Metadata
            wkgMetaPtr->pid = processId;
            currentPCB.uniquePid = processId;
            // set the process state to PROCESS_STATE_NEW
            currentPCB.process_state = PROCESS_STATE_NEW;
            // set the nextOpCode as a pointer to the first place metadataPtr started
            currentPCB.nextOpCode = wkgMetaPtr;
        }
        //
        // count number of io cycles
        // if ((compareString(command, "dev") == 0 && compareString(inOutArg, "in") == 0))
        // {
        //     integerArgumentOne = wkgMetaPtr->intArg2;
        //     ioCycleCount = ioCycleCount + integerArgumentOne;
        // }
        // if ((compareString(command, "dev") == 0 && compareString(inOutArg, "out") == 0))
        // {
        //     integerArgumentOne = wkgMetaPtr->intArg2;
        //     ioCycleCount = ioCycleCount + integerArgumentOne;
        // }
        if(compareString(command, "dev") == 0)
        {
            integerArgumentOne = wkgMetaPtr->intArg2;
            if(compareString(inOutArg, "in") == 0)
            {
                //
                ioCycleCount = ioCycleCount + integerArgumentOne;
            }
            else
            {
                //
                ioCycleCount = ioCycleCount + integerArgumentOne;
            }
        }
        // count number of cpu cycles
        if ((compareString(argument, "process") == 0 && compareString(command, "cpu") == 0))
        {
            integerArgumentOne = wkgMetaPtr->intArg2;
            cpuCycleCount = cpuCycleCount + integerArgumentOne;
            
        }
        if ((compareString(argument, "end") == 0 && compareString(command, "app") == 0))
        {
            // set the ioCycles from variable
            currentPCB.ioCycles = ioCycleCount;
            // set the cpuCycles from variable
            currentPCB.cpuCycles = cpuCycleCount;
            // set totalCycles from adding both IO/CPU
            currentPCB.totalCycles = ioCycleCount + cpuCycleCount;
            // set the time left from (ioCycles * ioCycleRate) + (cpuCycles * procCyclesRate)
            // this gets the number of ms in the process.
            currentPCB.timeLeft = timeLeftCount;
            // increment the PID counter
            processId = processId + 1;

            ioCycleCount = 0;
            cpuCycleCount = 0;
            timeLeftCount = 0.0;
            // needs to add nodes to the end and all data once parsed
            // do both the metadata and PCBs
            if(headPointer->headPtr == NULL)
            {
                //
                headPointer->headPtr = addProcess(currentPCB);
                wkgPCBPtr = headPointer->headPtr;
            }
            else
            {
                //
                wkgPCBPtr->nextPtr = addProcess(currentPCB);
                wkgPCBPtr = wkgPCBPtr->nextPtr;
            }
            
        }
        // move to the next bit of data
        wkgMetaPtr = wkgMetaPtr->nextNode;
        command = wkgMetaPtr->command;
        argument = wkgMetaPtr->strArg1;
        inOutArg = wkgMetaPtr->inOutArg;
        
    }
    // return null (temp) (should return the headpointer)
    return headPointer;
}

/*
Name: logOutput
Process: Takes in a string, and then outputs it to monitor AND/OR file
Function Input/Parameters: string (char *), file pointer (FILE *),
                           configuration data (ConfigDataType *),
                           end of simulator (bool)
Function Output/Parameters: none
Function Output/Returned: none
Device Input/Device: none
Device Output/Device: none
Dependencies: sprintf, ???
*/
void logOutput(ConfigDataType *configPtr, char *logStr, bool isEnd)
{
    FILE *fileWritePtr;
    fileWritePtr = fopen(configPtr->logToFileName, "w");
    if(fileWritePtr != NULL)
    {
        //
        fprintf(fileWritePtr, "%s", logStr);
        fprintf(stdout, "%s", logStr);
    }
    // no return, void
    // close the file, if at the end.
    // if(isEnd)
    // {
    //     //
    //     fclose(fileWritePtr);
    // }
    fclose(fileWritePtr);
}

/*
Name: runSim
Process: primary simulation driver
Function Input/Parameters: configuration data (ConfigDataType *),
                           metadata (OpCodeType *)
Function Output/Parameters: none
Function Output/Returned: none
Device Input/Device: none
Device Output/Device: none
Dependencies: ???
*/
void runSim(ConfigDataType *configPtr, OpCodeType *metaDataMstrPtr)
{
    // initialize function/variables
        // need two working pointers, one for master loop, one for internal loop
    OpCodeType *wkgPtrMaster;
        // currentTime variable that stores the time. [now unsure if needed]
        // need a variable for headPointer to point
    ProcessControlBlockLL *pcbList;
    ProcessControlBlock *pcbPtr;
        // string variable for nextCode, temp unused
    // char *nextCode;
        // string variable for the timer stuff
    char *simulatorOutput = "Simulator Start\n";

    // Operating System start timer goes here, log it.
    // sprintf(simulatorOutput, "Simulator start\n");
    logOutput(configPtr, simulatorOutput, false);

        // int variable for process to run
    int currentPid;
    // create the process list with createProcessList, store the pointed to address
    pcbList = createProcessList();
    // fill the process list given the metadata
    pcbList = fillProcessList(metaDataMstrPtr, pcbList);
    pcbPtr = pcbList->headPtr;
    // create temp strings
    char *command;
    char *argument;
    // int iterator
    int pcbIterator;

    // calculate pcb total time
    int totalPCBTime = 0;
    while(pcbPtr != NULL)
    {
        //
        totalPCBTime = totalPCBTime + pcbPtr->timeLeft;
        pcbPtr = pcbPtr->nextPtr;
    }
    pcbPtr = pcbList->headPtr;
    
    // set the current process id to the first scheduled process
    currentPid = scheduleProcess(pcbList, configPtr);
    // function holds master loop, loops until sys end opcode found OR wkgPtrMaster nextNode != NULL
    // while(wkgPtrMaster->nextNode != NULL && !(compareString(argument, "end") == 0 && compareString(command, "sys") == 0))
    // {
    //     currentPid = scheduleProcess(pcbList, configPtr);
    //     // will have a loop that goes from app start to app end for a PCB 
    //     // (checks to see if the next instruction is NOT app end), using getNextProcess?
    //         // this will getNextOpCode
    //         // this will checkForIO and run the IO operations, outputting to FILE * and/or monitor
    //             // checkForIO will need the FILE * passed, will need timer access, and ???
    //         // this will checkForCPU and run the CPU operations, outputting to FILE * and/or monitor
    //             // checkForCPU will need the FILE * passed, will need timer access, and ???
    //     // move the wkgPtrMaster to the next metadata block
    //     wkgPtrMaster = wkgPtrMaster->nextNode;
    //     // set the command and argument to the current cmd and arg
    //     command = wkgPtrMaster->command;
    //     argument = wkgPtrMaster->strArg1;
    // }
    // loop until current process is hit
    while(pcbPtr != NULL)
    {
        //
        if(pcbPtr->uniquePid == currentPid)
        {
            //
            printf("Process %d running", currentPid);
            pcbPtr->process_state = PROCESS_STATE_TERMINATED;
        }
        pcbPtr = pcbPtr->nextPtr;
    }
    
    //
    // deallocate the process list with destroyProcessList
    destroyProcessList(pcbList);
    // once complete, log the output to FILE if required
    logOutput(configPtr, "", true);
    // void function, no return.
}

/*
Name: scheduleProcess
Process: takes in the scheduling data, and then returns which process is to be ran
Function Input/Parameters: head pointer of PCB List (ProcessControlBlockLL *),
                           configuration data (ConfigDataType *)
Function Output/Parameters: none
Function Output/Returned: none
Device Input/Device: none
Device Output/Device: none
Dependencies: ???
*/
int scheduleProcess(ProcessControlBlockLL *headPointer, ConfigDataType *configPtr)
{
    ProcessControlBlock *wkgPtr;
    int returnPid = -1;
    wkgPtr = headPointer->headPtr;
    char *loggingStr;
    // switch case for each scheduling algorithm
    switch (configPtr->cpuSchedCode)
    {
        case CPU_SCHED_FCFS_N_CODE:
            // First Come, First Served, Non-preemptive Scheduling
            // only one implemented for now. returns first process without fail.
            // need to find whichever process is first, AND the state is NEW.
            // will set the state to READY, return the pid of the process which
                // was set to ready.
            
            // set every process in the list to READY from NEW
            while(wkgPtr != NULL)
            {
                //
                wkgPtr->process_state = PROCESS_STATE_READY;
                //printf("Process %d set to READY from NEW\n", wkgPtr->uniquePid);
                sprintf(loggingStr, "Process %d set to READY state from NEW state\n", wkgPtr->uniquePid);
                logOutput(configPtr, loggingStr, false);
                wkgPtr = wkgPtr->nextPtr;
            }

            // reset the pointer to get ready for selection of process
            wkgPtr = headPointer->headPtr;
            while(wkgPtr != NULL && (returnPid == -1))
            {
                // check if the process is NOT terminated
                if (wkgPtr->process_state == PROCESS_STATE_READY)
                {
                    //printf("Process %d Selected with %.0f ms remaining\n", wkgPtr->uniquePid, wkgPtr->timeLeft);
                    sprintf(loggingStr, "Process %d selected with %.0f ms remaining\n", wkgPtr->uniquePid, wkgPtr->timeLeft);
                    logOutput(configPtr, loggingStr, false);
                    returnPid = wkgPtr->uniquePid;
                }
                // move to next pointer
                wkgPtr = wkgPtr->nextPtr;
            }
            break;
        case CPU_SCHED_FCFS_P_CODE:
            // TODO: First Come, First Served, Preemptive Scheduling
            break;
        case CPU_SCHED_RR_P_CODE:
            // TODO: Round Robin Scheduling
            break;
        case CPU_SCHED_SJF_N_CODE:
            // TODO: Shortest Job First Scheduling
            break;
        case CPU_SCHED_SRTF_P_CODE:
            // TODO: Shortest Run-time First Scheduling
            break;
    }
    // return returnPid
    return returnPid;
}
/*
Current Note to programmer: do the scheduler, the runIO and runCPU functions, and then the FILE IO functions
this is all that is left so far, hopefully not too bad.
*/

// getNextProcess/scheduler/dispatcher run here, loads/"runs" the process
// getNextOpCode, not needed for Sim02 apparently, keep in mind.
// checkForIO, I think this gets passed the current process and runs the IO ops
// checkForCPU, I think this gets passed the current process and runs the CPU ops
// checkForMemory, I think this gets passed the current process
// and runs mem ops (not needed for Sim02)
// cpuIdler (not needed for Sim02)