/************************************************************************
 ************************************************************************
    FAUST compiler
    Copyright (C) 2003-2018 GRAME, Centre National de Creation Musicale
    ---------------------------------------------------------------------
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation; either version 2.1 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 ************************************************************************
 ************************************************************************/

#include <algorithm>
#include <iostream>

#include "exception.hh"
#include "recSchema.h"

using namespace std;

/**
 * Creates a new recursive schema (s1 ~ s2). The smallest component is
 * enlarged to the width of the other. The left and right horizontal
 * margins are computed according to the number of internal connections.
 */
schema* makeRecSchema(schema* s1, schema* s2)
{
    schema* a = makeEnlargedSchema(s1, s2->width());
    schema* b = makeEnlargedSchema(s2, s1->width());
    double  m = dWire * max(b->inputs(), b->outputs());
    double  w = a->width() + 2 * m;

    return new recSchema(a, b, w);
}

/**
 * Constructor of a recursive schema (s1 ~ s2). The two components
 * are supposed to have the same width.
 */
recSchema::recSchema(schema* s1, schema* s2, double width)
    : schema(s1->inputs() - s2->outputs(), s1->outputs(), width, s1->height() + s2->height()),
      fSchema1(s1),
      fSchema2(s2)
{
    // this version only accepts legal expressions of same width
    faustassert(s1->inputs() >= s2->outputs());
    faustassert(s1->outputs() >= s2->inputs());
    faustassert(s1->width() >= s2->width());

    // create the input and output points
    for (unsigned int i = 0; i < inputs(); i++) fInputPoint.push_back(point(0, 0));
    for (unsigned int i = 0; i < outputs(); i++) fOutputPoint.push_back(point(0, 0));
}

/**
 * The two subschema are placed centered vertically, s2 on top of s1.
 * The input and output points are computed.
 */
void recSchema::place(double ox, double oy, int orientation)
{
    beginPlace(ox, oy, orientation);

    double dx1 = (width() - fSchema1->width()) / 2;
    double dx2 = (width() - fSchema2->width()) / 2;

    // place the two sub diagrams
    if (orientation == kLeftRight) {
        fSchema2->place(ox + dx2, oy, kRightLeft);
        fSchema1->place(ox + dx1, oy + fSchema2->height(), kLeftRight);
    } else {
        fSchema1->place(ox + dx1, oy, kRightLeft);
        fSchema2->place(ox + dx2, oy + fSchema1->height(), kLeftRight);
    }

    // adjust delta space to orientation
    if (orientation == kRightLeft) {
        dx1 = -dx1;
    }

    // place input points
    for (unsigned int i = 0; i < inputs(); i++) {
        point p        = fSchema1->inputPoint(i + fSchema2->outputs());
        fInputPoint[i] = point(p.x - dx1, p.y);
    }

    // place output points
    for (unsigned int i = 0; i < outputs(); i++) {
        point p         = fSchema1->outputPoint(i);
        fOutputPoint[i] = point(p.x + dx1, p.y);
    }

    endPlace();
}

/**
 * The input points s1 ~ s2
 */
point recSchema::inputPoint(unsigned int i) const
{
    return fInputPoint[i];
}

/**
 * The output points s1 ~ s2
 */
point recSchema::outputPoint(unsigned int i) const
{
    return fOutputPoint[i];
}

/**
 * Draw the two subschema s1 and s2 as well as the implicit feedback
 * delays between s1 and s2.
 */
void recSchema::draw(device& dev)
{
    faustassert(placed());

    // draw the two subdiagrams
    fSchema1->draw(dev);
    fSchema2->draw(dev);

    // draw the implicit feedback delay to each fSchema2 input
    double dw = (orientation() == kLeftRight) ? dWire : -dWire;
    for (unsigned int i = 0; i < fSchema2->inputs(); i++) {
        const point& p = fSchema1->outputPoint(i);
        drawDelaySign(dev, p.x + i * dw, p.y, dw / 2);
    }
}

/**
 * Draw the delay sign of a feedback connection
 */
void recSchema::drawDelaySign(device& dev, double x, double y, double size)
{
    dev.trait(x - size / 2, y, x - size / 2, y - size);
    dev.trait(x - size / 2, y - size, x + size / 2, y - size);
    dev.trait(x + size / 2, y - size, x + size / 2, y);
}

/**
 * Draw the two subschema s1 and s2 as well as the feedback
 * connections between s1 and s2, and the feedfrom connections
 * beetween s2 and s1.
 */
void recSchema::collectTraits(collector& c)
{
    faustassert(placed());

    // draw the two subdiagrams
    fSchema1->collectTraits(c);
    fSchema2->collectTraits(c);

    // draw the feedback connections to each fSchema2 input
    for (unsigned int i = 0; i < fSchema2->inputs(); i++) {
        collectFeedback(c, fSchema1->outputPoint(i), fSchema2->inputPoint(i), i * dWire, outputPoint(i));
    }

    // draw the non recursive output lines
    for (unsigned int i = fSchema2->inputs(); i < outputs(); i++) {
        point p = fSchema1->outputPoint(i);
        point q = outputPoint(i);
        c.addTrait(trait(p, q));  // in->out order
    }

    // draw the input lines
    unsigned int skip = fSchema2->outputs();
    for (unsigned int i = 0; i < inputs(); i++) {
        point p = inputPoint(i);
        point q = fSchema1->inputPoint(i + skip);
        c.addTrait(trait(p, q));  // in->out order
    }

    // draw the feedfront connections from each fSchema2 output
    for (unsigned int i = 0; i < fSchema2->outputs(); i++) {
        collectFeedfront(c, fSchema2->outputPoint(i), fSchema1->inputPoint(i), i * dWire);
    }
}

/**
 * Draw a feedback connection between two points with an horizontal
 * displacement dx
 */
void recSchema::collectFeedback(collector& c, const point& src, const point& dst, double dx, const point& out)
{
    double ox = src.x + ((orientation() == kLeftRight) ? dx : -dx);
    double ct = (orientation() == kLeftRight) ? dWire / 2 : -dWire / 2;

    point up(ox, src.y - ct);
    point br(ox + ct / 2.0, src.y);

    c.addOutput(up);
    c.addOutput(br);
    c.addInput(br);

    c.addTrait(trait(up, point(ox, dst.y)));
    c.addTrait(trait(point(ox, dst.y), point(dst.x, dst.y)));
    c.addTrait(trait(src, br));
    c.addTrait(trait(br, out));
}

/**
 * Draw a feedfrom connection between two points with an horizontal
 * displacement dx
 */
void recSchema::collectFeedfront(collector& c, const point& src, const point& dst, double dx)
{
    double ox = src.x + ((orientation() == kLeftRight) ? -dx : dx);

    c.addTrait(trait(point(src.x, src.y), point(ox, src.y)));
    c.addTrait(trait(point(ox, src.y), point(ox, dst.y)));
    c.addTrait(trait(point(ox, dst.y), point(dst.x, dst.y)));
}
