{ MainLoop -- main loop }
unit game_m;

interface

uses level_m, enemy_packs_m;

type
    state = (
        gameLevelAnnounce, gameExit, gameMenu, gameStartLevel, gameKeyInfo,
        gamePause, gameUnpauseLevel, gameOver, gameComplete,
        gameLevelComplete, gameLevelLoop, gameContinueLevel
    );
    menuState = (menuNewGame, menuKeyInfo, menuContinue);
    gameState = record
        curExit: boolean;
        curMenu: menuState;
        curState: state;
        level, score, life: integer;
        enemyPack: enemyPackType;
        shutdown, newGame, unpause, levelInited, skipScene: boolean;
    end;

procedure InitGame(var g: gameState);
procedure MainLoop(var g: gameState);
procedure NextExitState(var g: gameState);
procedure PreviousExitState(var g: gameState);

implementation

uses arena_m, arena_graphics_m, crt, creature_m, graphics_m, hamster_m,
     keys_m, debug_m;

const
    KeyDelayMs = 25;
    MoveDelayMs = 120;
    EraseLifeThreshold = 10;
    AnnounceDelayMs = 1500;
    LevelCompleteDelayMs = 1500;
    LevelCount = 2;
    StartLifeN = 3;

procedure DecreaseLife(var life: integer);
begin
    if life = EraseLifeThreshold then
        EraseLifesNumber(life);
    life := life - 1;
    DrawLifesNumber(life)
end;

procedure InitGame(var g: gameState);
begin
    g.curMenu := menuNewGame;
    g.curState := gameMenu;
    g.enemyPack := enemyPack1;
    g.score := 0;
    g.shutdown := false;
    g.newGame := false;
    g.skipScene := false;
    g.life := StartLifeN
end;

procedure RunExitState(var g: gameState; var level: levelState);
begin
    DrawExit(g);
    while (g.curState = gameExit) and not g.shutdown do
    begin
        delay(KeyDelayMs);
        if keypressed then
            HandleKey(g, level)
    end;
    EraseExit
end;

procedure RunInfoState(var g: gameState; var level: levelState);
begin
    DrawKeyInfo;
    while (g.curState = gameKeyInfo) and not g.shutdown do
    begin
        delay(KeyDelayMs);
        if keypressed then
            HandleKey(g, level)
    end;
    EraseKeyInfo
end;

procedure RunPauseState(var g: gameState; var level: levelState);
begin
    DrawPause;
    while (g.curState = gamePause) and not g.shutdown do
    begin
        delay(KeyDelayMs);
        if keypressed then
            HandleKey(g, level)
    end;
    if g.curState = gameMenu then
        EraseLevel;
    if g.curState = gameUnpauseLevel then
    begin
        DrawLevelUnpause(level);
        level.unpause := true
    end
end;

procedure RunGameOverState(var g: gameState; var level: levelState);
begin
    DrawGameOver;
    DisposeCreatureList(level.enemyList);
    g.score := 0;
    g.life := StartLifeN;
    while (g.curState = gameOver) and not g.shutdown do
    begin
        delay(KeyDelayMs);
        if keypressed then
            HandleKey(g, level)
    end;
    EraseGameOver;
    if g.curState = gameLevelAnnounce then
    begin
        InitLevel(level, enemyPack1)
    end
    else
    begin
        g.levelInited := false;
        DisposeCreatureList(level.enemyList)
    end;
end;

procedure GameCutPart(var g: gameState; var level: levelState);
var
    beforeCut: integer;
begin
    beforeCut := level.cut;
    SetArenaBorder(level.t, level.a);
    ArenaCutPart(level.h, level.t, level.cut, level.a);
    FillCompleteBar(level.cut);
    g.score := g.score + (level.cut - beforeCut);
    DrawScore(g.score)
end;

procedure GameNextLevel(var g: gameState; var level: levelState);
begin
    g.level := g.level + 1;
    DisposeCreatureList(level.enemyList);
    if g.level > LevelCount then
    begin
        g.levelInited := false;
        g.curState := gameComplete
    end
    else
    begin
        g.curState := gameLevelComplete
    end
end;

procedure GameKillHamster(var g: gameState; var level: levelState);
begin
    if g.life <= 0 then
    begin
        g.curState := gameOver;
        Exit
    end;
    DecreaseLife(g.life);
    KillHamster(level.h, level.t, level.a);
    DrawAliveEnemies(level.enemyList);
    level.h.alive := true
end;

procedure PollGameKeys(var g: gameState; var level: levelState);
var
    i: integer;
begin
    for i := 1 to (MoveDelayMs div KeyDelayMs) do
    begin
        delay(KeyDelayMs);
        if keypressed then
            HandleKey(g, level);
        if g.curState = gamePause then
            break
    end
end;

procedure MakeEnemyTurnStages(var level: levelState);
begin
    KillCapturedEnemies(level.a, level.enemyList);
    TurnStubbornEnemies(level.a, level.enemyList);
    EraseEnemies(level.a, level.enemyList);
    MakeEnemySteps(level.a, level.h, level.t, level.enemyList);

    UpdateEnemyStates(level.enemyList);

    DrawAliveEnemies(level.enemyList)
end;

procedure MakeHamsterTurnStages(var g: gameState; var level: levelState);
begin
    if not level.h.alive then
        GameKillHamster(g, level);
    if g.curState = gameOver then
        exit;
    if not HamsterStepPossible(level.h, level.t, level.a) then
        StopCreature(level.h);
    if not ((level.h.dX = 0) and (level.h.dY = 0)) then
        MakeHamsterStep(level.h, level.t, level.a);
    DrawCreature(level.h)
end;

procedure LevelLoop(var g: gameState; var level: levelState);
begin
    while (g.curState = gameLevelLoop) and not g.shutdown do
    begin
        PollGameKeys(g, level);
        if g.curState = gamePause then
            break;
        if ArenaSplited(level.h, level.t, level.a) then
            GameCutPart(g, level);
        if IsLevelComplete(level) then
        begin
            GameNextLevel(g, level);
            if g.curState = gameComplete then
                EraseLevel;
            break
        end;
        MakeEnemyTurnStages(level);
        MakeHamsterTurnStages(g, level);
        if g.curState = gameOver then
        begin
            EraseLevel;
            break
        end
    end
end;

procedure RunLevelState(var g: gameState; var level: levelState);
begin
    if g.newGame then
    begin
        g.levelInited := true;
        g.level := 1;
        g.life := StartLifeN;
        g.newGame := false;
        g.score := 0
    end;
    g.curState := gameLevelLoop;
    InitLevel(level, enemyPack1);
    DrawLevel(level, g.life, g.score);
    LevelLoop(g, level)
end;

procedure UnpauseLevel(var g: gameState; var level: levelState);
begin
    if level.unpause then
        level.unpause := false
    else
        DrawLevel(level, g.life, g.score);
    g.curState := gameLevelLoop;
    LevelLoop(g, level)
end;

procedure ContinueLevel(var g: gameState; var level: levelState);
begin
    DrawLevel(level, g.life, g.score);
    g.curState := gamePause
end;

procedure RunMenuState(var g: gameState; var level: levelState);
var
    prevMenu: boolean = false;
begin
    g.curState := gameMenu;
    while (g.curState = gameMenu) and not g.shutdown do
    begin
        if (g.curState = gameMenu) and not prevMenu then
        begin
            DrawMenu(g);
            prevMenu := true
        end;
        delay(KeyDelayMs);
        if keypressed then
            HandleKey(g, level);
        if (g.curState <> gameMenu) and prevMenu then
        begin
            EraseMenu;
            prevMenu := false
        end;
        if (g.curState <> gameMenu) then
            if g.shutdown then
                break
    end
end;

procedure RunAnnounceState(var g: gameState; var level: levelState);
var
    i: integer;
begin
    DrawAnnounce(g.level);
    for i := 1 to AnnounceDelayMs div KeyDelayMs do
    begin
        delay(KeyDelayMs);
        if keypressed then
            HandleKey(g, level);
        if g.shutdown then
            exit;
        if g.skipScene then
            break
    end;
    g.skipScene := false;
    g.curState := gameStartLevel;
    EraseAnnounce(g.level)
end;

procedure RunLevelCompleteState(var g: gameState; var level: levelState);
var
    i: integer;
begin
    FillCellsCapture(level.a);
    DrawCreature(level.h);
    for i := 1 to LevelCompleteDelayMs div KeyDelayMs do
    begin
        delay(KeyDelayMs);
        if keypressed then
            HandleKey(g, level);
        if g.shutdown then
            exit;
        if g.skipScene then
            break
    end;
    g.skipScene := false;
    g.curState := gameLevelAnnounce;
    EraseLevel
end;

procedure RunGameCompleteState(var g: gameState; var level: levelState);
begin
    DrawGameComplete(g.score);
    while (g.curState = gameComplete) and not g.shutdown do
    begin
        delay(KeyDelayMs);
        if keypressed then
            HandleKey(g, level)
    end;
    EraseLevel
end;

procedure MainLoop(var g: gameState);
var
    level: levelState;
begin
    while not g.shutdown do
        case g.curState of
            gameLevelAnnounce:
                RunAnnounceState(g, level);
            gameExit:
                RunExitState(g, level);
            gameKeyInfo:
                RunInfoState(g, level);
            gamePause:
                RunPauseState(g, level);
            gameStartLevel:
                RunLevelState(g, level);
            gameUnpauseLevel:
                UnpauseLevel(g, level);
            gameContinueLevel:
                ContinueLevel(g, level);
            gameOver:
                RunGameOverState(g, level);
            gameMenu:
                RunMenuState(g, level);
            gameLevelComplete:
                RunLevelCompleteState(g, level);
            gameComplete:
                RunGameCompleteState(g, level)
        end;
    EraseAll
end;

procedure NextExitState(var g: gameState);
begin
    if not g.curExit then
        g.curExit := true
    else
        g.curExit := false
end;

procedure PreviousExitState(var g: gameState);
begin
    if g.curExit then
        g.curExit := false
    else
        g.curExit := true
end;

end.