var COL_MACD = "#0000ff";   //MACDの色
var COL_SIGNAL = "#ff0000"; //シグナルの色
var COL_OSCI = "#deb887";   //OSCIの色

var DAYS_EMA1 = 12;         //短期日数
var DAYS_EMA2 = 26;         //長期日数
var DAYS_SIGNAL = 9;        //シグナル日数
var DAYS_ES = DAYS_EMA2 + DAYS_SIGNAL;

var gEma1;  //EMA1
var gEma2;  //EMA2
var gMacd;  //MACD
var gSgnl9; //シグナル
var gOsci;  //OSCI

//MACD表示
function dspMACD(){
    var x;
    var y;
    var macdHeight;
    var heightHalf;
    var scale;
    var yRate;
    var maxOsci;
    var i;
    var osciYRat;

    //キャンバス取得
    getCanvas("idmacd");
    document.getElementById("vmacd1").text = "";
    document.getElementById("vmacd2").text = "";
    document.getElementById("vmacd3").text = "";
    document.getElementById("vmacd4").text = "";
    document.getElementById("vmacd5").text = "";
    if (gEd.length <= 36) {
        return;
    }

    gOsci = new Array(gEd.length);

    macdHeight = document.getElementById("idmacd").height;
    heightHalf = macdHeight / 2;    //MACD描画領域高さの半分

    calcEMA1();     //EMA1計算
    calcEMA2();     //EMA2計算
    calcMACD();     //MACD計算
    calcSignal();   //シグナルの計算

    //MACDの表示領域のスケール計算
    scale = caldMACDScale();

    //Y座標の比率計算
    yRate = macdHeight / scale;

    //OSCI計算
    maxOsci = 0
    for (i = DAYS_ES; i <= gEndIdx; i++) {
        gOsci[i] = gMacd[i] - gSgnl9[i];
        if (maxOsci < Math.abs(gOsci[i])) {
            maxOsci = Math.abs(gOsci[i]);
        }
    }
    osciYRate = macdHeight / (Math.abs(maxOsci) * 2);   //OSCIのYの比率計算

    //OSCI描画
    drawOSCI(osciYRate, heightHalf);

    //MACD描画
    drawMACD(yRate, heightHalf, scale);

    //シグナル描画
    drawSignal(yRate, heightHalf);
}

//EMA1計算
function calcEMA1() {
    var w = 0;
    var i;
    var k;

    gEma1 = new Array(gEd.length);

    //EMA1の先頭を計算（先頭は平均値）
    for (i = 0; i < DAYS_EMA1; i++) {
        w += gEd[i];
    }
    gEma1[DAYS_EMA1 - 1] = w / DAYS_EMA1;

    //EMA1の先頭以降を計算
    for (i = DAYS_EMA1; i <= gEndIdx; i++) {
        k = i - 1;
        gEma1[i] = gEma1[k] + (gEd[i] - gEma1[k]) * 2 / (DAYS_EMA1 + 1);
    }
}

//EMA2計算
function calcEMA2() {
    var w = 0;
    var i;

    gEma2 = new Array(gEd.length);

    //EMA2の先頭（平均）を求める
    for (i = 0; i < DAYS_EMA2; i++) {
        w += gEd[i];
    }
    gEma2[DAYS_EMA2 - 1] = w / DAYS_EMA2;

    //EMA2の先頭以降を計算
    for (i = DAYS_EMA2; i <= gEndIdx; i++) {
        var k = i - 1;
        gEma2[i] = gEma2[k] + (gEd[i] - gEma2[k]) * 2 / (DAYS_EMA2 + 1);
    }
}

//MACD計算
function calcMACD() {
    var i;

    gMacd = new Array(gEd.length);

    for (i = DAYS_EMA2; i <= gEndIdx; i++) {
        gMacd[i] = gEma1[i] - gEma2[i];
    }
}

//シグナルの計算
function calcSignal() {
    var i;
    var k;

    gSgnl9 = new Array(gEd.length);

    for (i = DAYS_EMA2; i <= gEndIdx; i++) {
        gSgnl9[i] = 0;
        for (k = i - (DAYS_SIGNAL - 1); k <= i; k++) {
            gSgnl9[i] += gMacd[k];
        }
        gSgnl9[i] /= DAYS_SIGNAL;
    }
}

//MACDの表示領域のスケール計算
//MACDとシグナルの最大値と最小値で絶対値が大きい方の２倍の値を返す
function caldMACDScale() {
    var i;
    var stIdx;
    var minVal = 9999999;
    var maxVal = -9999999;

    stIdx = gStartIdx;
    if (stIdx < DAYS_ES) {
        stIdx = DAYS_ES;
    }

    //MACDの最小、最大を計算
    for (i = stIdx; i <= gEndIdx; i++) {
        if (gMacd[i] < minVal) {
            minVal = gMacd[i];
        } else if (gMacd[i] > maxVal) {
            maxVal = gMacd[i];
        }
    }

    //シグナルの最小、最大を計算
    for (i = stIdx; i <= gEndIdx; i++) {
        if (gSgnl9[i] < minVal) {
            minVal = gSgnl9[i];
        } else if (gSgnl9[i] > maxVal) {
            maxVal = gSgnl9[i];
        }
    }

    if (Math.abs(minVal) <= Math.abs(maxVal)) {
        scale = (maxVal) * 2;
    } else {
        scale = (Math.abs(minVal)) * 2;
    }
    return scale;
}

//OSCI描画
// osciYRate  : Y座標比率
// heightHalf : 表示領域の高さ/2
function drawOSCI(osciYRate, heightHalf) {
    var x;
    var i;
    var osciy;
    var stIdx;

    gCtx.beginPath();
    gCtx.strokeStyle = COL_OSCI;
    gCtx.fillStyle = COL_OSCI;

    x = CNDL_INT - 0.5;
    stIdx = gStartIdx;
    if (stIdx <= DAYS_ES) {
        x += (CNDL * (DAYS_ES - stIdx));
        stIdx = DAYS_ES;
    }
    for (i = stIdx; i <= gEndIdx; i++) {
        if (gOsci[i] >= 0) {
            osciy = gOsci[i] * osciYRate;
            gCtx.fillRect(x,  heightHalf - osciy, CNDL_WIDTH, osciy);
        } else {
            osciy = gOsci[i] * (-1) * osciYRate;
            gCtx.fillRect(x,  heightHalf, CNDL_WIDTH, osciy);
        }
        x += CNDL;
    }
    gCtx.stroke();
    gCtx.closePath();
}

//MACD描画
// yRate      : Y座標比率
// heightHalf : 表示領域の高さ/2
// scale      : スケール
function drawMACD(yRate, heightHalf, scale) {
    var sw1;
    var sw2;
    var y;
    var i;

    //MACD目盛表示
    sw1 = shosu2keta(scale * 0.8);
    sw2 = shosu2keta(scale * 0.4);
    document.getElementById("vmacd1").text = sw1;
    document.getElementById("vmacd2").text = sw2;
    document.getElementById("vmacd3").text = "0";
    document.getElementById("vmacd4").text = "-" + sw2;
    document.getElementById("vmacd5").text = "-" + sw1;

    gCtx.beginPath();
    gCtx.strokeStyle = COL_MACD;

    stIdx = getDrawIdx(gStartIdx, 36);
    y = heightHalf - (gMacd[stIdx] * yRate);
    gCtx.moveTo(gX, y);

    for (i = stIdx + 1; i <= gEndIdx; i++) {
        gX += CNDL;
        y = heightHalf - (gMacd[i] * yRate);
        gCtx.lineTo(gX, y);
    }
    gCtx.stroke();
    gCtx.closePath();
}

//小数２桁で四捨五入し、少数２桁の文字列を返す
function shosu2keta(scale) {
    var w;
    var i;

    w = String(Math.round(scale * 100) / 100);
    i = w.indexOf(".");
    if (i == -1) {
        w += ".00";
    } else if (i == w.length - 2) {
        w += "0";
    }
    return w;
}

//シグナル描画
// yRate      : Y座標比率
// heightHalf : 表示領域の高さ/2
function drawSignal(yRate, heightHalf) {
    var y;
    var i;

    gCtx.beginPath();
    gCtx.strokeStyle = COL_SIGNAL;

    stIdx = getDrawIdx(gStartIdx, 36);
    y = heightHalf - (gSgnl9[stIdx] * yRate);
    gCtx.moveTo(gX, y);

    for (i = stIdx + 1; i <= gEndIdx; i++) {
        gX += CNDL;
        y = heightHalf - (gSgnl9[i] * yRate);
        gCtx.lineTo(gX, y);
    }
    gCtx.stroke();
    gCtx.closePath();
}