#include "service.h"
#include "os_utils.h"

// array of `service_item`s
std::vector<service_item*>* service_items = new std::vector<service_item*>();

// converts status code to readable string
std::string status_code_to_string(char code)
{
    switch (code)
    {
        case 0: return "PENDING ASSESSMENT";
        case 1: return "SERVICE IN PROGRESS";
        default: return "ERROR FINDING STATUS";
    }
}

// helper function to check if a vehicle exists
bool vehicle_exists(std::string name)
{
    // lambda function that finds the vehicle with a specific name
    auto item = std::find_if(service_items->begin(), service_items->end(),
        [name](service_item* x) -> bool {
            return x->vehicleCode == name;
        }
    );

    // if an item is found, return true, otherwise return false
    return item != service_items->end();
}

// display function, as required
void display()
{
    std::cout << "VEHICLE CODE / STATUS\n\n";

    // for each vehicle, print "<vehicle code> / <status>"
    for each (service_item* item in *service_items)
    {
        std::cout << item->vehicleCode + " / " + status_code_to_string(item->status) + "\n";
    }

    // if there are no vehicles, just print NO VEHICLES
    if (service_items->size() <= 0) {
        std::cout << "NO VEHICLES\n";
    }

    // print the option menu
    std::cout << "\n1. ADD VEHICLE\n2. UPDATE STATUS\n3. REMOVE VEHICLE\n4. EXIT\n";
}

// add vehicle function, as required
void add_vehicle(std::string name)
{
    // make a new vehicle and give it a name
    service_item* new_item = new service_item();
    new_item->vehicleCode = name;

    // add the vehicle to the list
    service_items->insert(service_items->end(), new_item);
}

// update vehicle function, as required
void update_vehicle(std::string name, char status)
{
    // make sure the vehicle even exists
    if (!vehicle_exists(name)) {
        std::cout << "THAT VEHICLE DOES NOT EXIST. TRY AGAIN.";
        std::getchar();
        return;
    }

    // make sure the status is either 0 or 1
    if (status < 0 || status > 1) {
        std::cout << "INVALID STATUS. MUST BE EITHER 0 OR 1.";
        std::getchar();
        return;
    }

    // lambda function to find a vehicle with a specific name
    auto item = std::find_if(service_items->begin(), service_items->end(),
        [name](service_item* x) -> bool {
            return x->vehicleCode == name;
        }
    );

    // set the vehicle's status
    (*item)->status = status;
}

// remove vehicle function, as required
void remove_vehicle(std::string name)
{
    // make sure the vehicle even exists
    if (!vehicle_exists(name)) {
        std::cout << "THAT VEHICLE DOES NOT EXIST. TRY AGAIN.";
        std::getchar();
        return;
    }

    // lambda function to remove a vehicle with a specific name
    auto removed = std::remove_if(service_items->begin(), service_items->end(),
        [name](service_item* x) -> bool {
            return x->vehicleCode == name;
        }
    );

    service_items->erase(removed, service_items->end()); // some non-important C++ bullshit
}

// save data function, as required
void save_data()
{
    // start with an empty string and fill it in the following format:
    // <vehicle code> [SPACE] <vehicle status>
    std::string output = "";
    for each (service_item* item in *service_items)
    {
        output += item->vehicleCode + " " + std::to_string(item->status) + "\n";
    }

    // write the output text to a file
    std::ofstream data_file("data.txt");
    data_file << output;
    data_file.close();
}

// load data function, as required
void load_data()
{
    // open file
    std::ifstream data_file("data.txt");

    // read each line
    std::string line;
    while (std::getline(data_file, line))
    {
        // if line is empty, ignore it
        if (line == "") continue;

        // split the line into an string array containing:
        // { 0: vehicle code, 1: vehicle status }
        auto parts = split(line);

        // add a vehicle using the name (which is the 0th item in the array)
        add_vehicle(parts[0]);

        // update the vehicle using the name (0) and the status it should have (1)
        update_vehicle(parts[0], std::stoi(parts[1]));
    }

    data_file.close();
}