/*

    ......... 2015 Ivan Mahonin

    This program is free software: you can redistribute it and/or modify

    it under the terms of the GNU General Public License as published by

    the Free Software Foundation, either version 3 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 General Public License for more details.

    You should have received a copy of the GNU General Public License

    along with this program.  If not, see <http://www.gnu.org/licenses/>.

*/

using System;

using System.Collections.Generic;

using System.Data.Linq;

using System.Drawing;

using System.IO;

using System.Globalization;

namespace Diagram {

    public class ActiveBlock {

        public Block block;

        public readonly List<ActiveLink> links = new List<ActiveLink>();

        public PointF position;

        public Font captionFont;

        public Font textFont;

        public float margin;

        public float padding;

        public Pen pen;

        public Brush brush;

        public string caption;

        public string text;

        public SizeF captionSize;

        public SizeF textSize;

        public float distance;

        public SizeF size;

        public SizeF clientSize;

        public PointF getCenter() {

            return new PointF(

                position.X + 0.5f*size.Width,

                position.Y + 0.5f*size.Height );

        }

        public void measure() {

            float width = captionFont.GetHeight() * 15f;

            caption = TextUtils.wrap(block.caption, width, captionFont);

            captionSize = TextUtils.measure(caption, captionFont);

            text = TextUtils.wrap(block.text, width, textFont);

            textSize = TextUtils.measure(text, textFont);

            if (caption != "" && text != "")

                distance = 0.3f * Math.Max(captionFont.GetHeight(), textFont.GetHeight());

            clientSize = new SizeF(

                Math.Max(captionSize.Width, textSize.Width),

                captionSize.Height + distance + textSize.Height );

            size = new SizeF(clientSize.Width + 2f*padding, clientSize.Height + 2f*padding);

        }

        public void draw(Graphics g) {

            Shapes.drawRoundRect(g, new RectangleF(position, size), 2f*padding, pen, brush);

            g.DrawString(

                caption,

                captionFont,

                Brushes.Black,

                new RectangleF(

                    position.X + 0.5f*(size.Width - captionSize.Width),

                    position.Y + padding,

                    captionSize.Width,

                    captionSize.Height ));

            g.DrawString(

                text,

                textFont,

                Brushes.Black,

                new RectangleF(

                    position.X + padding,

                    position.Y + padding + captionSize.Height + distance,

                    clientSize.Width,

                    clientSize.Height - captionSize.Height - distance ));

        }

        class LinkDesc {

            public ActiveLink link;

            public PointF src;

            public PointF dst;

        }

        class SideDesc {

            public PointF a;

            public PointF b;

            public PointF normal;

            public readonly List<LinkDesc> links = new List<LinkDesc>();

            public SideDesc(PointF a, PointF b) {

                this.a = a;

                this.b = b;

                float l = Geometry.lineLength(a, b);

                normal = new PointF((b.Y - a.Y)/l, (a.X - b.X)/l);

            }

        }

        public void placeLinks() {

            PointF lt = position;

            PointF rb = new PointF(lt.X + size.Width, lt.Y + size.Height);

            PointF lb = new PointF(lt.X, rb.Y);

            PointF rt = new PointF(rb.X, lt.Y);

            PointF center = getCenter();

            List<SideDesc> sides = new List<SideDesc>() {

                new SideDesc(lt, rt),

                new SideDesc(rt, rb),

                new SideDesc(rb, lb),

                new SideDesc(lb, lt) };

            foreach(ActiveLink link in links) {

                link.visible = false;

                LinkDesc linkDesc = new LinkDesc();

                linkDesc.link = link;

                if (link.src == this) {

                    linkDesc.src = center;

                    linkDesc.dst = link.dst.getCenter();

                } else {

                    linkDesc.src = link.src.getCenter();

                    linkDesc.dst = center;

                }

                foreach(SideDesc side in sides) {

                    PointF p;

                    if (Geometry.findIntersection(side.a, side.b, linkDesc.src, linkDesc.dst, out p)) {

                        link.visible = true;

                        linkDesc.src = p;

                        side.links.Add(linkDesc);

                        break;

                    }

                }

            }

            foreach(SideDesc side in sides) {

                side.links.Sort(delegate(LinkDesc a, LinkDesc b) {

                    return Geometry.comparePointsAtLine(a.src, b.src, side.a, side.b); });

                for(int i = 0; i < side.links.Count; ++i) {

                    ActiveLink link = side.links[i].link;

                    PointF p = Geometry.pointAtLine(side.a, side.b, i, side.links.Count, padding);

                    if (link.src == this) {

                        link.srcBase = p;

                        link.srcTangent = side.normal;

                        link.pen = pen;

                    } else {

                        link.dstBase = p;

                        link.dstTangent = new PointF(-side.normal.X, -side.normal.Y);

                    }

                }

            }

        }

    }

    public class ActiveLink {

        public Link link;

        public ActiveBlock src;

        public ActiveBlock dst;

        public SizeF arrowSize;

        public Pen pen;

        public bool visible;

        public PointF srcBase;

        public PointF srcTangent;

        public PointF dstBase;

        public PointF dstTangent;

        public PointF[] bezier;

        public PointF[] arrow;

        public static readonly PointF[] arrowTemplate = new PointF[] {

            new PointF(0f, 0f),

            new PointF(1f, 1f),

            new PointF(0f, 0.75f) };

        public static readonly float arrowOffset = 0.75f;

        public static PointF[] makeArrow(PointF point, PointF tangent, SizeF size) {

            PointF[] arrow = new PointF[2*arrowTemplate.Length];

            PointF tx = new PointF( -0.5f*tangent.Y*size.Width, 0.5f*tangent.X*size.Width  );

            PointF ty = new PointF( -tangent.X*size.Height, -tangent.Y*size.Height );

            for(int i = 0; i < arrowTemplate.Length; ++i) {

                arrow[i] = new PointF(

                    point.X + tx.X*arrowTemplate[i].X + ty.X*arrowTemplate[i].Y,

                    point.Y + tx.Y*arrowTemplate[i].X + ty.Y*arrowTemplate[i].Y );

                arrow[2*arrowTemplate.Length - i - 1] = new PointF(

                    point.X - tx.X*arrowTemplate[i].X + ty.X*arrowTemplate[i].Y,

                    point.Y - tx.Y*arrowTemplate[i].X + ty.Y*arrowTemplate[i].Y );

            }

            return arrow;

        }

        public void place() {

            if (!visible) return;

            float dx = 0.5f*Math.Abs(dstBase.X - srcBase.X);

            float dy = 0.5f*Math.Abs(dstBase.Y - srcBase.Y);

            float l = (float)Math.Sqrt(dx*dx + dy*dy);

            if (l < Geometry.precision) { visible = false; return; }

            dx = Math.Max(dx, 0.25f*l);

            dy = Math.Max(dy, 0.25f*l);

            float sl = l;

            if (Math.Abs(srcTangent.X) > Geometry.precision)

                sl = Math.Min(sl, dx/Math.Abs(srcTangent.X));

            if (Math.Abs(srcTangent.Y) > Geometry.precision)

                sl = Math.Min(sl, dy/Math.Abs(srcTangent.Y));

            PointF st = new PointF(srcTangent.X*sl, srcTangent.Y*sl);

            float dl = l;

            if (Math.Abs(dstTangent.X) > Geometry.precision)

                dl = Math.Min(dl, dx/Math.Abs(dstTangent.X));

            if (Math.Abs(dstTangent.Y) > Geometry.precision)

                dl = Math.Min(dl, dy/Math.Abs(dstTangent.Y));

            PointF dt = new PointF(dstTangent.X*sl, dstTangent.Y*sl);

            bezier = new PointF[] {

                srcBase,

                new PointF(srcBase.X + st.X, srcBase.Y + st.Y),

                new PointF(dstBase.X - dt.X, dstBase.Y - dt.Y),

                new PointF(dstBase.X - dstTangent.X*(arrowOffset*arrowSize.Height + 0.5f*pen.Width),

                           dstBase.Y - dstTangent.Y*(arrowOffset*arrowSize.Height + 0.5f*pen.Width))

            };

            arrow = makeArrow(

                new PointF(dstBase.X - 0.5f*dstTangent.X*pen.Width,

                           dstBase.Y - 0.5f*dstTangent.Y*pen.Width),

                dstTangent,

                arrowSize );

        }

        public void draw(Graphics g) {

            if (!visible) return;

            g.DrawBeziers(pen, bezier);

            g.FillPolygon(new SolidBrush(pen.Color), arrow);

            //g.DrawPolygon(pen, arrow);

        }

    }

    public class ActiveDiagram {

        public Diagram diagram;

        public readonly Dictionary<string, PointF> positions = new Dictionary<string, PointF>();

        public Font captionFont;

        public Font textFont;

        public float margin;

        public float padding;

        public SizeF arrowSize;

        public Pen pen;

        public Brush brush;

        public readonly Dictionary<string, ActiveBlock> blocks = new Dictionary<string, ActiveBlock>();

        public readonly Dictionary<string, ActiveLink> links = new Dictionary<string, ActiveLink>();

        public RectangleF bounds;

        public void savePositions(string filename) {

            remeberPositions();

            CultureInfo ci = new CultureInfo("en-US");

            List<string> lines = new List<string>();

            foreach(KeyValuePair<string, PointF> pair in positions) {

                lines.Add(pair.Key);

                lines.Add(pair.Value.X.ToString(ci));

                lines.Add(pair.Value.Y.ToString(ci));

            }

            File.Create(filename).Close();

            File.WriteAllLines(filename, lines);

        }

        public void loadPositions(string filename) {

            CultureInfo ci = new CultureInfo("en-US");

            string[] lines = File.ReadAllLines(filename);

            for(int i = 0; i < lines.Length - 2; i += 3) {

                string k = lines[i];

                PointF p = new PointF(

                    float.Parse(lines[i+1], ci),

                    float.Parse(lines[i+2], ci) );

                if (positions.ContainsKey(k))

                    positions[k] = p;

                else

                    positions.Add(k, p);

            }

            restorePositions();

        }

        public void remeberPositions() {

            foreach(KeyValuePair<string, ActiveBlock> pair in blocks)

                if (positions.ContainsKey(pair.Key))

                    positions[pair.Key] = pair.Value.position;

                else

                    positions.Add(pair.Key, pair.Value.position);

        }

        public void restorePositions() {

            foreach(KeyValuePair<string, ActiveBlock> pair in blocks)

                if (positions.ContainsKey(pair.Key))

                    pair.Value.position = positions[pair.Key];

            placeLinks();

        }

        // insert/remove blocks and links calculate sizes

        public void reloadDiagram() {

            remeberPositions();

            bool retry;

            // blocks

            foreach(KeyValuePair<string, ActiveBlock> pair in blocks)

                pair.Value.block = null;

            foreach(KeyValuePair<string, Block> pair in diagram.blocks) {

                if (!blocks.ContainsKey(pair.Key))

                    blocks.Add(pair.Key, new ActiveBlock());

                ActiveBlock b = blocks[pair.Key];

                b.block = pair.Value;

                b.links.Clear();

                b.captionFont = captionFont;

                b.textFont = textFont;

                b.margin = margin;

                b.padding = padding;

                b.pen = new Pen(new SolidBrush(b.block.color), pen.Width);

                b.brush = brush;

            }

            retry = true;

            while(retry) {

                retry = false;

                foreach(KeyValuePair<string, ActiveBlock> pair in blocks)

                    if (pair.Value.block == null)

                        { blocks.Remove(pair.Key); retry = true; break; }

            }

            // links

            foreach(KeyValuePair<string, ActiveLink> pair in links)

                pair.Value.link = null;

            foreach(KeyValuePair<string, Link> pair in diagram.links) {

                if ( blocks.ContainsKey(pair.Value.srcId)

                  && blocks.ContainsKey(pair.Value.dstId) )

                {

                    if (!links.ContainsKey(pair.Key))

                        links.Add(pair.Key, new ActiveLink());

                    ActiveLink l = links[pair.Key];

                    l.link = pair.Value;

                    l.src = blocks[l.link.srcId];

                    l.src.links.Add(l);

                    l.dst = blocks[l.link.dstId];

                    l.dst.links.Add(l);

                    l.arrowSize = arrowSize;

                    l.pen = pen;

                }

            }

            retry = true;

            while(retry) {

                retry = false;

                foreach(KeyValuePair<string, ActiveLink> pair in links)

                    if (pair.Value.link == null)

                        { links.Remove(pair.Key); retry = true; break; }

            }

            measureBlocks();

        }

        public void measureBlocks() {

            foreach(KeyValuePair<string, ActiveBlock> pair in blocks)

                pair.Value.measure();

            placeLinks();

        }

        public void placeLinks() {

            foreach(KeyValuePair<string, ActiveBlock> pair in blocks)

                pair.Value.placeLinks();

            foreach(KeyValuePair<string, ActiveLink> pair in links)

                pair.Value.place();

            recalcBounds();

        }

        public void recalcBounds() {

            if (blocks.Count == 0) { bounds = new RectangleF(); return; }

            float minx = float.PositiveInfinity;

            float miny = float.PositiveInfinity;

            float maxx = float.NegativeInfinity;

            float maxy = float.NegativeInfinity;

            foreach(KeyValuePair<string, ActiveBlock> pair in blocks) {

                minx = Math.Min(minx, pair.Value.position.X - pair.Value.margin);

                miny = Math.Min(miny, pair.Value.position.Y - pair.Value.margin);

                maxx = Math.Max(maxx, pair.Value.position.X + pair.Value.size.Width + pair.Value.margin);

                maxy = Math.Max(maxy, pair.Value.position.Y + pair.Value.size.Height + pair.Value.margin);

            }

            bounds = new RectangleF(minx, miny, maxx - minx, maxy - miny);

        }

        public void draw(Graphics g) {

            foreach(KeyValuePair<string, ActiveLink> pair in links)

                pair.Value.draw(g);

            foreach(KeyValuePair<string, ActiveBlock> pair in blocks)

                pair.Value.draw(g);

        }

    }

}