// Unity C# reference source
// Copyright (c) Unity Technologies. For terms of use, see
// https://unity3d.com/legal/licenses/Unity_Reference_Only_License

using UnityEngine;

namespace UnityEditor
{
    internal class LayoutDropdownWindow : PopupWindowContent
    {
        class Styles
        {
            public Color tableHeaderColor;
            public Color tableLineColor;
            public Color parentColor;
            public Color selfColor;
            public Color simpleAnchorColor;
            public Color stretchAnchorColor;
            public Color anchorCornerColor;
            public Color pivotColor;

            public GUIStyle frame;
            public GUIStyle label = new GUIStyle(EditorStyles.miniLabel);

            public Styles()
            {
                frame = new GUIStyle();
                Texture2D tex = new Texture2D(4, 4);
                tex.SetPixels(new Color[] {
                    Color.white, Color.white, Color.white, Color.white,
                    Color.white, Color.clear, Color.clear, Color.white,
                    Color.white, Color.clear, Color.clear, Color.white,
                    Color.white, Color.white, Color.white, Color.white
                });
                tex.filterMode = FilterMode.Point;
                tex.Apply();
                tex.hideFlags = HideFlags.HideAndDontSave;
                frame.normal.background = tex;
                frame.border = new RectOffset(2, 2, 2, 2);

                label.alignment = TextAnchor.LowerCenter;

                if (EditorGUIUtility.isProSkin)
                {
                    tableHeaderColor = new Color(0.18f, 0.18f, 0.18f, 1);
                    tableLineColor = new Color(1, 1, 1, 0.3f);
                    parentColor = new Color(0.4f, 0.4f, 0.4f, 1);
                    selfColor = new Color(0.6f, 0.6f, 0.6f, 1);
                    simpleAnchorColor = new Color(0.7f, 0.3f, 0.3f, 1);
                    stretchAnchorColor = new Color(0.0f, 0.6f, 0.8f, 1);
                    anchorCornerColor = new Color(0.8f, 0.6f, 0.0f, 1);
                    pivotColor = new Color(0.0f, 0.6f, 0.8f, 1);
                }
                else
                {
                    tableHeaderColor = new Color(0.8f, 0.8f, 0.8f, 1);
                    tableLineColor = new Color(0, 0, 0, 0.5f);
                    parentColor = new Color(0.55f, 0.55f, 0.55f, 1);
                    selfColor = new Color(0.2f, 0.2f, 0.2f, 1);
                    simpleAnchorColor = new Color(0.8f, 0.3f, 0.3f, 1);
                    stretchAnchorColor = new Color(0.2f, 0.5f, 0.9f, 1);
                    anchorCornerColor = new Color(0.6f, 0.4f, 0.0f, 1);
                    pivotColor = new Color(0.2f, 0.5f, 0.9f, 1);
                }
            }
        }
        static Styles s_Styles;

        SerializedProperty m_AnchorMin;
        SerializedProperty m_AnchorMax;

        Vector2[,] m_InitValues;

        const int kTopPartHeight = 38;
        static float[] kPivotsForModes = new float[] { 0, 0.5f, 1, 0.5f, 0.5f }; // Only for actual modes, not for Undefined.
        static string[] kHLabels = new string[] { "custom", "left", "center", "right", "stretch", "%" };
        static string[] kVLabels = new string[] { "custom", "top", "middle", "bottom", "stretch", "%" };

        public enum LayoutMode { Undefined = -1, Min = 0, Middle = 1, Max = 2, Stretch = 3 }

        public LayoutDropdownWindow(SerializedObject so)
        {
            m_AnchorMin = so.FindProperty("m_AnchorMin");
            m_AnchorMax = so.FindProperty("m_AnchorMax");

            m_InitValues = new Vector2[so.targetObjects.Length, 4];
            for (int i = 0; i < so.targetObjects.Length; i++)
            {
                RectTransform gui = so.targetObjects[i] as RectTransform;
                m_InitValues[i, 0] = gui.anchorMin;
                m_InitValues[i, 1] = gui.anchorMax;
                m_InitValues[i, 2] = gui.anchoredPosition;
                m_InitValues[i, 3] = gui.sizeDelta;
            }
        }

        public override void OnOpen()
        {
            EditorApplication.modifierKeysChanged += editorWindow.Repaint;
        }

        public override void OnClose()
        {
            EditorApplication.modifierKeysChanged -= editorWindow.Repaint;
        }

        public override Vector2 GetWindowSize()
        {
            return new Vector2(262, 262 + kTopPartHeight);
        }

        public override void OnGUI(Rect rect)
        {
            if (s_Styles == null)
                s_Styles = new Styles();

            if (Event.current.type == EventType.KeyDown && Event.current.keyCode == KeyCode.Return)
                editorWindow.Close();

            GUI.Label(new Rect(rect.x + 5, rect.y + 3, rect.width - 10, 16), EditorGUIUtility.TrTextContent("Anchor Presets"), EditorStyles.boldLabel);
            GUI.Label(new Rect(rect.x + 5, rect.y + 3 + 16, rect.width - 10, 16), EditorGUIUtility.TrTextContent("Shift: Also set pivot     Alt: Also set position"), EditorStyles.label);

            Color oldColor = GUI.color;
            GUI.color = s_Styles.tableLineColor * oldColor;
            GUI.DrawTexture(new Rect(0, kTopPartHeight - 1, 400, 1), EditorGUIUtility.whiteTexture);
            GUI.color = oldColor;

            GUI.BeginGroup(new Rect(rect.x, rect.y + kTopPartHeight, rect.width, rect.height - kTopPartHeight));
            TableGUI(rect);
            GUI.EndGroup();
        }

        static LayoutMode SwappedVMode(LayoutMode vMode)
        {
            if (vMode == LayoutMode.Min)
                return LayoutMode.Max;
            else if (vMode == LayoutMode.Max)
                return LayoutMode.Min;
            return vMode;
        }

        internal static void DrawLayoutModeHeadersOutsideRect(Rect rect,
            SerializedProperty anchorMin,
            SerializedProperty anchorMax,
            SerializedProperty position,
            SerializedProperty sizeDelta)
        {
            LayoutMode hMode = GetLayoutModeForAxis(anchorMin, anchorMax, 0);
            LayoutMode vMode = GetLayoutModeForAxis(anchorMin, anchorMax, 1);
            vMode = SwappedVMode(vMode);
            DrawLayoutModeHeaderOutsideRect(rect, 0, hMode);
            DrawLayoutModeHeaderOutsideRect(rect, 1, vMode);
        }

        internal static void DrawLayoutModeHeaderOutsideRect(Rect position, int axis, LayoutMode mode)
        {
            Rect headerRect = new Rect(position.x, position.y - 16, position.width, 16);

            Matrix4x4 normalMatrix = GUI.matrix;
            if (axis == 1)
                GUIUtility.RotateAroundPivot(-90, position.center);

            int index = (int)(mode) + 1;
            GUI.Label(headerRect, axis == 0 ? kHLabels[index] : kVLabels[index], s_Styles.label);

            GUI.matrix = normalMatrix;
        }

        void TableGUI(Rect rect)
        {
            int padding = 6;
            int size = 31 + padding * 2;
            int spacing = 0;
            int[] groupings = new int[] { 15, 30, 30, 30, 45, 45 };

            Color oldColor = GUI.color;

            int headerW = 62;
            GUI.color = s_Styles.tableHeaderColor * oldColor;
            GUI.DrawTexture(new Rect(0, 0, 400, headerW), EditorGUIUtility.whiteTexture);
            GUI.DrawTexture(new Rect(0, 0, headerW, 400), EditorGUIUtility.whiteTexture);
            GUI.color = s_Styles.tableLineColor * oldColor;
            GUI.DrawTexture(new Rect(0, headerW, 400, 1), EditorGUIUtility.whiteTexture);
            GUI.DrawTexture(new Rect(headerW, 0, 1, 400), EditorGUIUtility.whiteTexture);
            GUI.color = oldColor;

            LayoutMode hMode = GetLayoutModeForAxis(m_AnchorMin, m_AnchorMax, 0);
            LayoutMode vMode = GetLayoutModeForAxis(m_AnchorMin, m_AnchorMax, 1);
            vMode = SwappedVMode(vMode);

            bool doPivot = Event.current.shift;
            bool doPosition = Event.current.alt;

            int number = 5;

            for (int i = 0; i < number; i++)
            {
                LayoutMode cellHMode = (LayoutMode)(i - 1);

                for (int j = 0; j < number; j++)
                {
                    LayoutMode cellVMode = (LayoutMode)(j - 1);

                    if (i == 0 && j == 0 && vMode >= 0 && hMode >= 0)
                        continue;

                    Rect position = new Rect(
                            i * (size + spacing) + groupings[i],
                            j * (size + spacing) + groupings[j],
                            size,
                            size);

                    if (j == 0 && !(i == 0 && hMode != LayoutMode.Undefined))
                        DrawLayoutModeHeaderOutsideRect(position, 0, cellHMode);
                    if (i == 0 && !(j == 0 && vMode != LayoutMode.Undefined))
                        DrawLayoutModeHeaderOutsideRect(position, 1, cellVMode);

                    bool selected = (cellHMode == hMode) && (cellVMode == vMode);

                    bool selectedHeader = false;
                    if (i == 0 && cellVMode == vMode)
                        selectedHeader = true;
                    if (j == 0 && cellHMode == hMode)
                        selectedHeader = true;

                    if (Event.current.type == EventType.Repaint)
                    {
                        if (selected)
                        {
                            GUI.color = Color.white * oldColor;
                            s_Styles.frame.Draw(position, false, false, false, false);
                        }
                        else if (selectedHeader)
                        {
                            GUI.color = new Color(1, 1, 1, 0.7f) * oldColor;
                            s_Styles.frame.Draw(position, false, false, false, false);
                        }
                    }

                    DrawLayoutMode(
                        new Rect(position.x + padding, position.y + padding, position.width - padding * 2, position.height - padding * 2),
                        cellHMode, cellVMode,
                        doPivot, doPosition);

                    int clickCount = Event.current.clickCount;
                    if (GUI.Button(position, GUIContent.none, GUIStyle.none))
                    {
                        SetLayoutModeForAxis(m_AnchorMin, 0, cellHMode, doPivot, doPosition, m_InitValues);
                        SetLayoutModeForAxis(m_AnchorMin, 1, SwappedVMode(cellVMode), doPivot, doPosition, m_InitValues);
                        if (clickCount == 2)
                            editorWindow.Close();
                        else
                            editorWindow.Repaint();
                    }
                }
            }
            GUI.color = oldColor;
        }

        static LayoutMode GetLayoutModeForAxis(
            SerializedProperty anchorMin,
            SerializedProperty anchorMax,
            int axis)
        {
            if (anchorMin.vector2Value[axis] == 0 && anchorMax.vector2Value[axis] == 0)
                return LayoutMode.Min;
            if (anchorMin.vector2Value[axis] == 0.5f && anchorMax.vector2Value[axis] == 0.5f)
                return LayoutMode.Middle;
            if (anchorMin.vector2Value[axis] == 1 && anchorMax.vector2Value[axis] == 1)
                return LayoutMode.Max;
            if (anchorMin.vector2Value[axis] == 0 && anchorMax.vector2Value[axis] == 1)
                return LayoutMode.Stretch;
            return LayoutMode.Undefined;
        }

        static void SetLayoutModeForAxis(
            SerializedProperty anchorMin,
            int axis, LayoutMode layoutMode,
            bool doPivot, bool doPosition, Vector2[,] defaultValues)
        {
            anchorMin.serializedObject.ApplyModifiedProperties();

            for (int i = 0; i < anchorMin.serializedObject.targetObjects.Length; i++)
            {
                RectTransform gui = anchorMin.serializedObject.targetObjects[i] as RectTransform;
                Undo.RecordObject(gui, "Change Rectangle Anchors");

                if (doPosition)
                {
                    if (defaultValues != null && defaultValues.Length > i)
                    {
                        Vector2 temp;

                        temp = gui.anchorMin;
                        temp[axis] = defaultValues[i, 0][axis];
                        gui.anchorMin = temp;

                        temp = gui.anchorMax;
                        temp[axis] = defaultValues[i, 1][axis];
                        gui.anchorMax = temp;

                        temp = gui.anchoredPosition;
                        temp[axis] = defaultValues[i, 2][axis];
                        gui.anchoredPosition = temp;

                        temp = gui.sizeDelta;
                        temp[axis] = defaultValues[i, 3][axis];
                        gui.sizeDelta = temp;
                    }
                }

                if (doPivot && layoutMode != LayoutMode.Undefined)
                {
                    RectTransformEditor.SetPivotSmart(gui, kPivotsForModes[(int)layoutMode], axis, true, true);
                }

                Vector2 refPosition = Vector2.zero;
                switch (layoutMode)
                {
                    case LayoutMode.Min:
                        RectTransformEditor.SetAnchorSmart(gui, 0, axis, false, true, true);
                        RectTransformEditor.SetAnchorSmart(gui, 0, axis, true, true, true);
                        refPosition = gui.offsetMin;
                        EditorUtility.SetDirty(gui);
                        break;
                    case LayoutMode.Middle:
                        RectTransformEditor.SetAnchorSmart(gui, 0.5f, axis, false, true, true);
                        RectTransformEditor.SetAnchorSmart(gui, 0.5f, axis, true, true, true);
                        refPosition = (gui.offsetMin + gui.offsetMax) * 0.5f;
                        EditorUtility.SetDirty(gui);
                        break;
                    case LayoutMode.Max:
                        RectTransformEditor.SetAnchorSmart(gui, 1, axis, false, true, true);
                        RectTransformEditor.SetAnchorSmart(gui, 1, axis, true, true, true);
                        refPosition = gui.offsetMax;
                        EditorUtility.SetDirty(gui);
                        break;
                    case LayoutMode.Stretch:
                        RectTransformEditor.SetAnchorSmart(gui, 0, axis, false, true, true);
                        RectTransformEditor.SetAnchorSmart(gui, 1, axis, true, true, true);
                        refPosition = (gui.offsetMin + gui.offsetMax) * 0.5f;
                        EditorUtility.SetDirty(gui);
                        break;
                }

                if (doPosition)
                {
                    // Handle position
                    Vector2 rectPosition = gui.anchoredPosition;
                    rectPosition[axis] -= refPosition[axis];
                    gui.anchoredPosition = rectPosition;

                    // Handle sizeDelta
                    if (layoutMode == LayoutMode.Stretch)
                    {
                        Vector2 rectSizeDelta = gui.sizeDelta;
                        rectSizeDelta[axis] = 0;
                        gui.sizeDelta = rectSizeDelta;
                    }
                }
            }
            anchorMin.serializedObject.Update();
        }

        internal static void DrawLayoutMode(Rect rect,
            SerializedProperty anchorMin,
            SerializedProperty anchorMax,
            SerializedProperty position,
            SerializedProperty sizeDelta)
        {
            LayoutMode hMode = GetLayoutModeForAxis(anchorMin, anchorMax, 0);
            LayoutMode vMode = GetLayoutModeForAxis(anchorMin, anchorMax, 1);
            vMode = SwappedVMode(vMode);
            DrawLayoutMode(rect, hMode, vMode);
        }

        internal static void DrawLayoutMode(Rect position, LayoutMode hMode, LayoutMode vMode)
        {
            DrawLayoutMode(position, hMode, vMode, false, false);
        }

        internal static void DrawLayoutMode(Rect position, LayoutMode hMode, LayoutMode vMode, bool doPivot)
        {
            DrawLayoutMode(position, hMode, vMode, doPivot, false);
        }

        internal static void DrawLayoutMode(Rect position, LayoutMode hMode, LayoutMode vMode, bool doPivot, bool doPosition)
        {
            if (s_Styles == null)
                s_Styles = new Styles();

            Color oldColor = GUI.color;

            // Make parent size the largest possible square, but enforce it's an uneven number.
            int parentWidth = (int)Mathf.Min(position.width, position.height);
            if (parentWidth % 2 == 0)
                parentWidth--;

            int selfWidth = parentWidth / 2;
            if (selfWidth % 2 == 0)
                selfWidth++;

            Vector2 parentSize = parentWidth * Vector2.one;
            Vector2 selfSize = selfWidth * Vector2.one;
            Vector2 padding = (position.size - parentSize) / 2;
            padding.x = Mathf.Floor(padding.x);
            padding.y = Mathf.Floor(padding.y);
            Vector2 padding2 = (position.size - selfSize) / 2;
            padding2.x = Mathf.Floor(padding2.x);
            padding2.y = Mathf.Floor(padding2.y);

            Rect outer = new Rect(position.x + padding.x, position.y + padding.y, parentSize.x, parentSize.y);
            Rect inner = new Rect(position.x + padding2.x, position.y + padding2.y, selfSize.x, selfSize.y);
            if (doPosition)
            {
                for (int axis = 0; axis < 2; axis++)
                {
                    LayoutMode mode = (axis == 0 ? hMode : vMode);

                    if (mode == LayoutMode.Min)
                    {
                        Vector2 center = inner.center;
                        center[axis] += outer.min[axis] - inner.min[axis];
                        inner.center = center;
                    }
                    if (mode == LayoutMode.Middle)
                    {
                        // TODO
                    }
                    if (mode == LayoutMode.Max)
                    {
                        Vector2 center = inner.center;
                        center[axis] += outer.max[axis] - inner.max[axis];
                        inner.center = center;
                    }
                    if (mode == LayoutMode.Stretch)
                    {
                        Vector2 innerMin = inner.min;
                        Vector2 innerMax = inner.max;
                        innerMin[axis] = outer.min[axis];
                        innerMax[axis] = outer.max[axis];
                        inner.min = innerMin;
                        inner.max = innerMax;
                    }
                }
            }

            Rect anchor = new Rect();
            Vector2 min = Vector2.zero;
            Vector2 max = Vector2.zero;
            for (int axis = 0; axis < 2; axis++)
            {
                LayoutMode mode = (axis == 0 ? hMode : vMode);

                if (mode == LayoutMode.Min)
                {
                    min[axis] = outer.min[axis] + 0.5f;
                    max[axis] = outer.min[axis] + 0.5f;
                }
                if (mode == LayoutMode.Middle)
                {
                    min[axis] = outer.center[axis];
                    max[axis] = outer.center[axis];
                }
                if (mode == LayoutMode.Max)
                {
                    min[axis] = outer.max[axis] - 0.5f;
                    max[axis] = outer.max[axis] - 0.5f;
                }
                if (mode == LayoutMode.Stretch)
                {
                    min[axis] = outer.min[axis] + 0.5f;
                    max[axis] = outer.max[axis] - 0.5f;
                }
            }
            anchor.min = min;
            anchor.max = max;

            // Draw parent rect
            if (Event.current.type == EventType.Repaint)
            {
                GUI.color = s_Styles.parentColor * oldColor;
                s_Styles.frame.Draw(outer, false, false, false, false);
            }

            // Draw anchor lines
            if (hMode != LayoutMode.Undefined && hMode != LayoutMode.Stretch)
            {
                GUI.color = s_Styles.simpleAnchorColor * oldColor;
                GUI.DrawTexture(new Rect(anchor.xMin - 0.5f, outer.y + 1, 1, outer.height - 2), EditorGUIUtility.whiteTexture);
                GUI.DrawTexture(new Rect(anchor.xMax - 0.5f, outer.y + 1, 1, outer.height - 2), EditorGUIUtility.whiteTexture);
            }
            if (vMode != LayoutMode.Undefined && vMode != LayoutMode.Stretch)
            {
                GUI.color = s_Styles.simpleAnchorColor * oldColor;
                GUI.DrawTexture(new Rect(outer.x + 1, anchor.yMin - 0.5f, outer.width - 2, 1), EditorGUIUtility.whiteTexture);
                GUI.DrawTexture(new Rect(outer.x + 1, anchor.yMax - 0.5f, outer.width - 2, 1), EditorGUIUtility.whiteTexture);
            }

            // Draw stretch mode arrows
            if (hMode == LayoutMode.Stretch)
            {
                GUI.color = s_Styles.stretchAnchorColor * oldColor;
                DrawArrow(new Rect(inner.x + 1, inner.center.y - 0.5f, inner.width - 2, 1));
            }
            if (vMode == LayoutMode.Stretch)
            {
                GUI.color = s_Styles.stretchAnchorColor * oldColor;
                DrawArrow(new Rect(inner.center.x - 0.5f, inner.y + 1, 1, inner.height - 2));
            }

            // Draw self rect
            if (Event.current.type == EventType.Repaint)
            {
                GUI.color = s_Styles.selfColor * oldColor;
                s_Styles.frame.Draw(inner, false, false, false, false);
            }

            // Draw pivot
            if (doPivot && hMode != LayoutMode.Undefined && vMode != LayoutMode.Undefined)
            {
                Vector2 pivot = new Vector2(
                        Mathf.Lerp(inner.xMin + 0.5f, inner.xMax - 0.5f, kPivotsForModes[(int)hMode]),
                        Mathf.Lerp(inner.yMin + 0.5f, inner.yMax - 0.5f, kPivotsForModes[(int)vMode])
                        );

                GUI.color = s_Styles.pivotColor * oldColor;
                GUI.DrawTexture(new Rect(pivot.x - 2.5f, pivot.y - 1.5f, 5, 3), EditorGUIUtility.whiteTexture);
                GUI.DrawTexture(new Rect(pivot.x - 1.5f, pivot.y - 2.5f, 3, 5), EditorGUIUtility.whiteTexture);
            }

            // Draw anchor corners
            if (hMode != LayoutMode.Undefined && vMode != LayoutMode.Undefined)
            {
                GUI.color = s_Styles.anchorCornerColor * oldColor;
                GUI.DrawTexture(new Rect(anchor.xMin - 1.5f, anchor.yMin - 1.5f, 2, 2), EditorGUIUtility.whiteTexture);
                GUI.DrawTexture(new Rect(anchor.xMax - 0.5f, anchor.yMin - 1.5f, 2, 2), EditorGUIUtility.whiteTexture);
                GUI.DrawTexture(new Rect(anchor.xMin - 1.5f, anchor.yMax - 0.5f, 2, 2), EditorGUIUtility.whiteTexture);
                GUI.DrawTexture(new Rect(anchor.xMax - 0.5f, anchor.yMax - 0.5f, 2, 2), EditorGUIUtility.whiteTexture);
            }

            GUI.color = oldColor;
        }

        static void DrawArrow(Rect lineRect)
        {
            GUI.DrawTexture(lineRect, EditorGUIUtility.whiteTexture);
            if (lineRect.width == 1)
            {
                GUI.DrawTexture(new Rect(lineRect.x - 1, lineRect.y + 1, 3, 1), EditorGUIUtility.whiteTexture);
                GUI.DrawTexture(new Rect(lineRect.x - 2, lineRect.y + 2, 5, 1), EditorGUIUtility.whiteTexture);
                GUI.DrawTexture(new Rect(lineRect.x - 1, lineRect.yMax - 2, 3, 1), EditorGUIUtility.whiteTexture);
                GUI.DrawTexture(new Rect(lineRect.x - 2, lineRect.yMax - 3, 5, 1), EditorGUIUtility.whiteTexture);
            }
            else
            {
                GUI.DrawTexture(new Rect(lineRect.x + 1, lineRect.y - 1, 1, 3), EditorGUIUtility.whiteTexture);
                GUI.DrawTexture(new Rect(lineRect.x + 2, lineRect.y - 2, 1, 5), EditorGUIUtility.whiteTexture);
                GUI.DrawTexture(new Rect(lineRect.xMax - 2, lineRect.y - 1, 1, 3), EditorGUIUtility.whiteTexture);
                GUI.DrawTexture(new Rect(lineRect.xMax - 3, lineRect.y - 2, 1, 5), EditorGUIUtility.whiteTexture);
            }
        }
    }
}
