// Copyright (c) 2008-2023 the Urho3D project
// License: MIT

#include <Urho3D/Core/CoreEvents.h>
#include <Urho3D/Core/ProcessUtils.h>
#include <Urho3D/Core/Timer.h>
#include <Urho3D/Engine/Console.h>
#include <Urho3D/Engine/Engine.h>
#include <Urho3D/Engine/EngineEvents.h>
#include <Urho3D/Input/Input.h>
#include <Urho3D/IO/Log.h>
#include <Urho3D/UI/Button.h>

#include "ConsoleInput.h"

#include <Urho3D/DebugNew.h>

// Expands to this example's entry-point
URHO3D_DEFINE_APPLICATION_MAIN(ConsoleInput)

// Hunger level descriptions
const char* hungerLevels[] = {
    "bursting",
    "well-fed",
    "fed",
    "hungry",
    "very hungry",
    "starving"
};

// Urho threat level descriptions
const char* urhoThreatLevels[] = {
    "Suddenly Urho appears from a dark corner of the fish tank",
    "Urho seems to have his eyes set on you",
    "Urho is homing in on you mercilessly"
};

ConsoleInput::ConsoleInput(Context* context) :
    Sample(context)
{
}

void ConsoleInput::Start()
{
    // Execute base class startup
    Sample::Start();

    // Subscribe to console commands and the frame update
    SubscribeToEvent(E_CONSOLECOMMAND, URHO3D_HANDLER(ConsoleInput, HandleConsoleCommand));
    SubscribeToEvent(E_UPDATE, URHO3D_HANDLER(ConsoleInput, HandleUpdate));

    // Subscribe key down event
    SubscribeToEvent(E_KEYDOWN, URHO3D_HANDLER(ConsoleInput, HandleEscKeyDown));
    UnsubscribeFromEvent(E_KEYUP);

    // Hide logo to make room for the console
    SetLogoVisible(false);

    // Show the console by default, make it large. Console will show the text edit field when there is at least one
    // subscriber for the console command event
    auto* console = GetSubsystem<Console>();
    console->SetNumRows(GetSubsystem<Graphics>()->GetHeight() / 16);
    console->SetNumBufferedRows(2 * console->GetNumRows());
    console->SetCommandInterpreter(GetTypeName());
    console->SetVisible(true);
    console->GetCloseButton()->SetVisible(false);
    console->AddAutoComplete("help");
    console->AddAutoComplete("eat");
    console->AddAutoComplete("hide");
    console->AddAutoComplete("wait");
    console->AddAutoComplete("score");
    console->AddAutoComplete("quit");

    // Show OS mouse cursor
    GetSubsystem<Input>()->SetMouseVisible(true);

    // Set the mouse mode to use in the sample
    Sample::InitMouseMode(MM_FREE);

    // Open the operating system console window (for stdin / stdout) if not open yet
    OpenConsoleWindow();

    // Initialize game and print the welcome message
    StartGame();

    // Randomize from system clock
    SetRandomSeed(Time::GetSystemTime());
}

void ConsoleInput::HandleConsoleCommand(StringHash eventType, VariantMap& eventData)
{
    using namespace ConsoleCommand;
    if (eventData[P_ID].GetString() == GetTypeName())
        HandleInput(eventData[P_COMMAND].GetString());
}

void ConsoleInput::HandleUpdate(StringHash eventType, VariantMap& eventData)
{
    // Check if there is input from stdin
    String input = GetConsoleInput();
    if (input.Length())
        HandleInput(input);
}

void ConsoleInput::HandleEscKeyDown(StringHash eventType, VariantMap& eventData)
{
    // Unlike the other samples, exiting the engine when ESC is pressed instead of just closing the console
    if (eventData[KeyDown::P_KEY].GetI32() == KEY_ESCAPE && GetPlatform() != "Web")
        engine_->Exit();
}

void ConsoleInput::StartGame()
{
    Print("Welcome to the Urho adventure game! You are the newest fish in the tank; your\n"
          "objective is to survive as long as possible. Beware of hunger and the merciless\n"
          "predator cichlid Urho, who appears from time to time. Evading Urho is easier\n"
          "with an empty stomach. Type 'help' for available commands.");

    gameOn_ = true;
    foodAvailable_ = false;
    eatenLastTurn_ = false;
    numTurns_ = 0;
    hunger_ = 2;
    urhoThreat_ = 0;
}

void ConsoleInput::EndGame(const String& message)
{
    Print(message);
    Print("Game over! You survived " + String(numTurns_) + " turns.\n"
          "Do you want to play again (Y/N)?");

    gameOn_ = false;
}

void ConsoleInput::Advance()
{
    if (urhoThreat_ > 0)
    {
        ++urhoThreat_;
        if (urhoThreat_ > 3)
        {
            EndGame("Urho has eaten you!");
            return;
        }
    }
    else if (urhoThreat_ < 0)
        ++urhoThreat_;
    if (urhoThreat_ == 0 && Random() < 0.2f)
        ++urhoThreat_;

    if (urhoThreat_ > 0)
        Print(String(urhoThreatLevels[urhoThreat_ - 1]) + ".");

    if ((numTurns_ & 3u) == 0 && !eatenLastTurn_)
    {
        ++hunger_;
        if (hunger_ > 5)
        {
            EndGame("You have died from starvation!");
            return;
        }
        else
            Print("You are " + String(hungerLevels[hunger_]) + ".");
    }

    eatenLastTurn_ = false;

    if (foodAvailable_)
    {
        Print("The floating pieces of fish food are quickly eaten by other fish in the tank.");
        foodAvailable_ = false;
    }
    else if (Random() < 0.15f)
    {
        Print("The overhead dispenser drops pieces of delicious fish food to the water!");
        foodAvailable_ = true;
    }

    ++numTurns_;
}

void ConsoleInput::HandleInput(const String& input)
{
    String inputLower = input.ToLower().Trimmed();
    if (inputLower.Empty())
    {
        Print("Empty input given!");
        return;
    }

    if (inputLower == "quit" || inputLower == "exit")
        engine_->Exit();
    else if (gameOn_)
    {
        // Game is on
        if (inputLower == "help")
            Print("The following commands are available: 'eat', 'hide', 'wait', 'score', 'quit'.");
        else if (inputLower == "score")
            Print("You have survived " + String(numTurns_) + " turns.");
        else if (inputLower == "eat")
        {
            if (foodAvailable_)
            {
                Print("You eat several pieces of fish food.");
                foodAvailable_ = false;
                eatenLastTurn_ = true;
                hunger_ -= (hunger_ > 3) ? 2 : 1;
                if (hunger_ < 0)
                {
                    EndGame("You have killed yourself by over-eating!");
                    return;
                }
                else
                    Print("You are now " + String(hungerLevels[hunger_]) + ".");
            }
            else
                Print("There is no food available.");

            Advance();
        }
        else if (inputLower == "wait")
        {
            Print("Time passes...");
            Advance();
        }
        else if (inputLower == "hide")
        {
            if (urhoThreat_ > 0)
            {
                bool evadeSuccess = hunger_ > 2 || Random() < 0.5f;
                if (evadeSuccess)
                {
                    Print("You hide behind the thick bottom vegetation, until Urho grows bored.");
                    urhoThreat_ = -2;
                }
                else
                    Print("Your movements are too slow; you are unable to hide from Urho.");
            }
            else
                Print("There is nothing to hide from.");

            Advance();
        }
        else
            Print("Cannot understand the input '" + input + "'.");
    }
    else
    {
        // Game is over, wait for (y)es or (n)o reply
        if (inputLower[0] == 'y')
            StartGame();
        else if (inputLower[0] == 'n')
            engine_->Exit();
        else
            Print("Please answer 'y' or 'n'.");
    }
}

void ConsoleInput::Print(const String& output)
{
    // Logging appears both in the engine console and stdout
    URHO3D_LOGRAW(output + "\n");
}