/*
 * Copyright (c) 2007-2013 Scott Lembcke and Howling Moon Software
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
module demo.Player;

import core.stdc.stdlib;

import std.math;

alias M_PI_2 = PI_2;

import demo.dchip;

import demo.ChipmunkDebugDraw;
import demo.ChipmunkDemo;
import demo.types;

enum PLAYER_VELOCITY = 500.0;

enum PLAYER_GROUND_ACCEL_TIME = 0.1;
enum PLAYER_GROUND_ACCEL = (PLAYER_VELOCITY / PLAYER_GROUND_ACCEL_TIME);

enum PLAYER_AIR_ACCEL_TIME = 0.25;
enum PLAYER_AIR_ACCEL = (PLAYER_VELOCITY / PLAYER_AIR_ACCEL_TIME);

enum JUMP_HEIGHT = 50.0;
enum JUMP_BOOST_HEIGHT = 55.0;
enum FALL_VELOCITY = 900.0;
enum GRAVITY = 2000.0;

static cpBody * playerBody  = null;
static cpShape* playerShape = null;

static cpFloat remainingBoost = 0;
static cpBool  grounded       = cpFalse;
static cpBool  lastJumpState  = cpFalse;

static void SelectPlayerGroundNormal(cpBody* body_, cpArbiter* arb, cpVect* groundNormal)
{
    cpVect n = cpvneg(cpArbiterGetNormal(arb, 0));

    if (n.y > groundNormal.y)
    {
        (*groundNormal) = n;
    }
}

static void playerUpdateVelocity(cpBody* body_, cpVect gravity, cpFloat damping, cpFloat dt)
{
    int jumpState = (ChipmunkDemoKeyboard.y > 0.0f);

    // Grab the grounding normal from last frame
    cpVect groundNormal = cpvzero;
    cpBodyEachArbiter(playerBody, safeCast!cpBodyArbiterIteratorFunc(&SelectPlayerGroundNormal), &groundNormal);

    grounded = (groundNormal.y > 0.0);

    if (groundNormal.y < 0.0f)
        remainingBoost = 0.0f;

    // Do a normal-ish update
    cpBool boost = (jumpState && remainingBoost > 0.0f);
    cpVect g     = (boost ? cpvzero : gravity);
    cpBodyUpdateVelocity(body_, g, damping, dt);

    // Target horizontal speed for air/ground control
    cpFloat target_vx = PLAYER_VELOCITY * ChipmunkDemoKeyboard.x;

    // Update the surface velocity and friction
    cpVect surface_v = cpv(target_vx, 0.0);
    playerShape.surface_v = surface_v;
    playerShape.u         = (grounded ? PLAYER_GROUND_ACCEL / GRAVITY : 0.0);

    // Apply air control if not grounded
    if (!grounded)
    {
        // Smoothly accelerate the velocity
        playerBody.v.x = cpflerpconst(playerBody.v.x, target_vx, PLAYER_AIR_ACCEL * dt);
    }

    body_.v.y = cpfclamp(body_.v.y, -FALL_VELOCITY, INFINITY);
}

static void update(cpSpace* space, double dt)
{
    int jumpState = (ChipmunkDemoKeyboard.y > 0.0f);

    // If the jump key was just pressed this frame, jump!
    if (jumpState && !lastJumpState && grounded)
    {
        cpFloat jump_v = cpfsqrt(2.0 * JUMP_HEIGHT * GRAVITY);
        playerBody.v = cpvadd(playerBody.v, cpv(0.0, jump_v));

        remainingBoost = JUMP_BOOST_HEIGHT / jump_v;
    }

    // Step the space
    cpSpaceStep(space, dt);

    remainingBoost -= dt;
    lastJumpState   = cast(bool)jumpState;
}

static cpSpace* init()
{
    cpSpace* space = cpSpaceNew();
    space.iterations = 10;
    space.gravity    = cpv(0, -GRAVITY);

    //	space.sleepTimeThreshold = 1000;
    space.enableContactGraph = cpTrue;

    cpBody * body_;
    cpBody * staticBody = space.staticBody;
    cpShape* shape;

    // Create segments around the edge of the screen.
    shape         = cpSpaceAddShape(space, cpSegmentShapeNew(staticBody, cpv(-320, -240), cpv(-320, 240), 0.0f));
    shape.e      = 1.0f;
    shape.u      = 1.0f;
    shape.layers = NOT_GRABABLE_MASK;

    shape         = cpSpaceAddShape(space, cpSegmentShapeNew(staticBody, cpv(320, -240), cpv(320, 240), 0.0f));
    shape.e      = 1.0f;
    shape.u      = 1.0f;
    shape.layers = NOT_GRABABLE_MASK;

    shape         = cpSpaceAddShape(space, cpSegmentShapeNew(staticBody, cpv(-320, -240), cpv(320, -240), 0.0f));
    shape.e      = 1.0f;
    shape.u      = 1.0f;
    shape.layers = NOT_GRABABLE_MASK;

    shape         = cpSpaceAddShape(space, cpSegmentShapeNew(staticBody, cpv(-320, 240), cpv(320, 240), 0.0f));
    shape.e      = 1.0f;
    shape.u      = 1.0f;
    shape.layers = NOT_GRABABLE_MASK;

    // Set up the player
    body_    = cpSpaceAddBody(space, cpBodyNew(1.0f, INFINITY));
    body_.p = cpv(0, -200);
    body_.velocity_func = &playerUpdateVelocity;
    playerBody = body_;

    shape = cpSpaceAddShape(space, cpBoxShapeNew3(body_, cpBBNew(-15.0, -27.5, 15.0, 27.5), 10.0));

    //	shape = cpSpaceAddShape(space, cpSegmentShapeNew(playerBody, cpvzero, cpv(0, radius), radius));
    shape.e = 0.0f;
    shape.u = 0.0f;
    shape.collision_type = 1;
    playerShape = shape;

    // Add some boxes to jump on
    for (int i = 0; i < 6; i++)
    {
        for (int j = 0; j < 3; j++)
        {
            body_    = cpSpaceAddBody(space, cpBodyNew(4.0f, INFINITY));
            body_.p = cpv(100 + j * 60, -200 + i * 60);

            shape    = cpSpaceAddShape(space, cpBoxShapeNew(body_, 50, 50));
            shape.e = 0.0f;
            shape.u = 0.7f;
        }
    }

    return space;
}

static void destroy(cpSpace* space)
{
    ChipmunkDemoFreeSpaceChildren(space);
    cpSpaceFree(space);
}

ChipmunkDemo Player = {
    "Platformer Player Controls",
    1.0 / 180.0,
    &init,
    &update,
    &ChipmunkDemoDefaultDrawImpl,
    &destroy,
};