import React, { useEffect, useRef, useState } from 'react';
import * as XLSX from 'xlsx';
import * as d3 from 'd3';
import './App.css';

function App() {
  const [people, setPeople] = useState([]);
  const [mode, setMode] = useState('hierarchy');
  const [strength, setStrength] = useState(0.5);
  const svgRef = useRef();
  const [projectNodes, setProjectNodes] = useState([]);
  // Add state for focused person
  const [focusedPerson, setFocusedPerson] = useState(null);

  useEffect(() => {
    fetch('/people.xlsx')
      .then(res => res.arrayBuffer())
      .then(data => {
        const workbook = XLSX.read(data, { type: 'array' });
        const sheet = workbook.Sheets[workbook.SheetNames[0]];
        const json = XLSX.utils.sheet_to_json(sheet);
        setPeople(json);
      });
  }, []);

  useEffect(() => {
    if (!people.length) return;
    if (mode !== 'projects') return;
    // Build project nodes
    const projectSet = new Set();
    people.forEach(p => (p.Projects || '').split(';').forEach(proj => proj && projectSet.add(proj.trim())));
    setProjectNodes(Array.from(projectSet).map(p => ({ id: p, type: 'project' })));
  }, [people, mode]);

  useEffect(() => {
    if (!people.length) return;
    const width = window.innerWidth;
    const height = window.innerHeight;
    const svg = d3.select(svgRef.current);
    svg.selectAll('*').remove();
    svg.attr('width', width).attr('height', height)
      .style('display', 'block')
      .style('background', '#fff');

    // Add zoom and pan
    const zoom = d3.zoom()
      .scaleExtent([0.2, 3])
      .on('zoom', (event) => {
        svg.select('g.viz').attr('transform', event.transform);
      });
    svg.call(zoom);

    // Create a group for all viz elements
    const g = svg.append('g').attr('class', 'viz');

    if (mode === 'projects' || mode === 'technologies') {
      // --- Central node mode (projects or technologies) ---
      const key = mode === 'projects' ? 'Projects' : 'Technologies';
      const color = mode === 'projects' ? '#fbb4ae' : '#b2df8a';
      // 1. Create nodes: central (project/tech), people (orbiting)
      const centralSet = new Set();
      people.forEach(p => (p[key] || '').split(';').forEach(val => val && centralSet.add(val.trim())));
      const centrals = Array.from(centralSet).map(p => ({ id: p, type: 'central' }));
      const nodes = [
        ...centrals,
        ...people.map(p => ({ ...p, type: 'person' }))
      ];
      // 2. Create links: person <-> central
      const links = [];
      people.forEach(person => {
        (person[key] || '').split(';').forEach(val => {
          val = val.trim();
          if (!val) return;
          links.push({ source: val, target: person.Name, label: val });
        });
      });
      // 3. D3 simulation
      const simulation = d3.forceSimulation(nodes)
        // Repel all nodes by default
        .force('charge', d3.forceManyBody().strength(d => d.type === 'central' ? -500 * strength : -200 * strength)) // More repulsion
        // Center the layout
        .force('center', d3.forceCenter(width / 2, height / 2))
        // Only attract people to centrals via links
        .force('link', d3.forceLink(links)
          .id(d => d.type === 'central' ? d.id : d.Name)
          .distance(250)
          .strength(strength * 0.5)
        ) // Weaker attraction, longer distance
        // Prevent overlap
        .force('collide', d3.forceCollide().radius(d => d.type === 'central' ? 75 : 65));

      // Draw links
      const link = g.append('g')
        .attr('stroke', 'var(--secondary-green)')
        .attr('stroke-width', 2)
        .selectAll('line')
        .data(links)
        .enter().append('line');

      // Draw link labels
      const linkLabels = g.append('g')
        .selectAll('text')
        .data(links)
        .enter().append('text')
        .attr('font-size', 12)
        .attr('fill', 'var(--dark-gray)')
        .attr('text-anchor', 'middle')
        .text(d => d.label);

      // Draw nodes
      const node = g.selectAll('g.node')
        .data(nodes)
        .enter().append('g')
        .attr('class', 'node')
        .call(d3.drag()
          .on('start', dragstarted)
          .on('drag', dragged)
          .on('end', dragended));

      node.append('circle')
        .attr('r', d => d.type === 'central' ? 55 : 45)
        .attr('fill', d => d.type === 'central' ? 'var(--main-green)' : 'var(--secondary-green)')
        .attr('stroke', d => d.type === 'central' ? 'var(--secondary-green)' : 'var(--main-green)')
        .attr('stroke-width', 3);

      node.filter(d => d.type === 'person').append('image')
        .attr('xlink:href', d => `/images/${d.Image}`)
        .attr('x', -25)
        .attr('y', -25)
        .attr('width', 50)
        .attr('height', 50)
        .attr('clip-path', 'circle(25px at 25px 25px)');

      node.append('text')
        .attr('y', d => d.type === 'central' ? 5 : 55)
        .attr('text-anchor', 'middle')
        .attr('font-weight', d => d.type === 'central' ? 'bold' : 'normal')
        .attr('fill', d => d.type === 'central' ? 'var(--white)' : 'var(--dark-gray)')
        .text(d => d.type === 'central' ? d.id : d.Name);

      node.filter(d => d.type === 'person').append('title')
        .text(d => `Projects: ${d.Projects}\nTech: ${d.Technologies}\nHobbies: ${d.Hobbies}`);

      simulation.on('tick', () => {
        link
          .attr('x1', d => getNode(d.source).x)
          .attr('y1', d => getNode(d.source).y)
          .attr('x2', d => getNode(d.target).x)
          .attr('y2', d => getNode(d.target).y);
        linkLabels
          .attr('x', d => (getNode(d.source).x + getNode(d.target).x) / 2)
          .attr('y', d => (getNode(d.source).y + getNode(d.target).y) / 2 - 10)
          .text(d => d.label);
        node.attr('transform', d => `translate(${d.x},${d.y})`);
      });

      function getNode(n) {
        if (typeof n === 'string') return nodes.find(nd => nd.id === n || nd.Name === n) || {};
        return n;
      }
      function dragstarted(event, d) {
        if (!event.active) simulation.alphaTarget(0.3).restart();
        d.fx = d.x;
        d.fy = d.y;
      }
      function dragged(event, d) {
        d.fx = event.x;
        d.fy = event.y;
      }
      function dragended(event, d) {
        if (!event.active) simulation.alphaTarget(0);
        d.fx = null;
        d.fy = null;
      }
      return;
    }

    // --- D3 force simulation for hierarchy ---
    // Only define links for non-central modes
    let links = [];
    function dragstarted(event, d) {
      if (!event.active) {
        d.fx = d.x;
        d.fy = d.y;
      }
      d3.select(this).raise();
    }
    function dragged(event, d) {
      d.fx = event.x;
      d.fy = event.y;
    }
    function dragended(event, d) {
      if (!event.active) {
        d.fx = null;
        d.fy = null;
      }
    }
    if (mode === 'hierarchy') {
      // Improved hierarchy: CEO -> Project Leaders, Project Leaders -> Developers in their projects
      const ceo = people.find(p => p.Hierarchy === 'CEO');
      // Project leaders: CTO, Manager
      const leaders = people.filter(p => p.Hierarchy === 'CTO' || p.Hierarchy === 'Manager');
      // 1. CEO to project leaders (no link label)
      leaders.forEach(leader => {
        if (ceo) links.push({ source: ceo, target: leader });
      });
      // 2. Project leaders to their developers (if a dev shares a project with a leader, connect)
      const developers = people.filter(p => p.Hierarchy === 'Developer');
      leaders.forEach(leader => {
        const leaderProjects = (leader.Projects || '').split(';').map(p => p.trim());
        developers.forEach(dev => {
          const devProjects = (dev.Projects || '').split(';').map(p => p.trim());
          // If any project overlaps, connect
          if (leaderProjects.some(proj => devProjects.includes(proj))) {
            links.push({ source: leader, target: dev, label: '' });
          }
        });
      });
      // --- D3 force simulation ---
      const simulation = d3.forceSimulation(people)
        .force('charge', d3.forceManyBody().strength(-300 * strength)) // Increased repulsion
        .force('center', d3.forceCenter(width / 2, height / 2))
        .force('link', d3.forceLink(links).id(d => d.Name).distance(250).strength(strength * 0.5)) // Decreased attraction, longer distance
        .force('collide', d3.forceCollide().radius(65))
        // Strong gravity to bottom for developers
        .force('y', d3.forceY(d => {
          if (d.Hierarchy === 'Developer') return height - 100;
          if (d.Hierarchy === 'CTO' || d.Hierarchy === 'Manager') return height / 2;
          return 100;
        }).strength(0.5));

      const link = g.append('g')
        .attr('stroke', 'var(--secondary-green)')
        .attr('stroke-width', 2)
        .selectAll('line')
        .data(links)
        .enter().append('line');

      // Remove link labels for CEO to leaders
      const linkLabels = g.append('g')
        .selectAll('text')
        .data(links.filter(l => l.label))
        .enter().append('text')
        .attr('font-size', 12)
        .attr('fill', 'var(--dark-gray)')
        .attr('text-anchor', 'middle')
        .text(d => d.label);

      const node = g.selectAll('g.node')
        .data(people)
        .enter().append('g')
        .attr('class', 'node')
        .call(d3.drag()
          .on('start', dragstarted)
          .on('drag', dragged)
          .on('end', dragended));

      node.append('circle')
        .attr('r', 50)
        .attr('fill', d => d.Hierarchy === 'CEO' ? 'var(--main-green)' : d.Hierarchy === 'CTO' || d.Hierarchy === 'Manager' ? 'var(--secondary-green)' : 'var(--white)')
        .attr('stroke', d => d.Hierarchy === 'Developer' ? 'var(--main-green)' : 'var(--secondary-green)')
        .attr('stroke-width', 3);

      node.append('image')
        .attr('xlink:href', d => `/images/${d.Image}`)
        .attr('x', -30)
        .attr('y', -30)
        .attr('width', 60)
        .attr('height', 60)
        .attr('clip-path', 'circle(30px at 30px 30px)');

      node.append('text')
        .attr('y', 60)
        .attr('text-anchor', 'middle')
        .attr('font-weight', d => d.Hierarchy === 'CEO' ? 'bold' : 'normal')
        .attr('fill', d => d.Hierarchy === 'CEO' ? '#111' : 'var(--dark-gray)')
        .text(d => d.Name);

      node.append('title')
        .text(d => `Projects: ${d.Projects}\nTech: ${d.Technologies}\nHobbies: ${d.Hobbies}`);

      simulation.on('tick', () => {
        link
          .attr('x1', d => d.source.x)
          .attr('y1', d => d.source.y)
          .attr('x2', d => d.target.x)
          .attr('y2', d => d.target.y);
        linkLabels
          .attr('x', d => (d.source.x + d.target.x) / 2)
          .attr('y', d => (d.source.y + d.target.y) / 2 - 10)
          .text(d => d.label);
        node.attr('transform', d => `translate(${d.x},${d.y})`);
      });
      return;
    } else if (mode === 'technologies' || mode === 'projects') {
      // handled above
    } else {
      // Link people sharing technologies (fallback)
      const techMap = {};
      people.forEach(p => {
        (p.Technologies || '').split(';').forEach(tech => {
          tech = tech.trim();
          if (!tech) return;
          if (!techMap[tech]) techMap[tech] = [];
          techMap[tech].push(p);
        });
      });
      Object.entries(techMap).forEach(([tech, arr]) => {
        for (let i = 0; i < arr.length; ++i) {
          for (let j = i + 1; j < arr.length; ++j) {
            links.push({ source: arr[i], target: arr[j], label: tech });
          }
        }
      });
    }
    if (mode === 'hierarchy') {
      const simulation = d3.forceSimulation(people)
        .force('charge', d3.forceManyBody().strength(-300 * strength)) // Increased repulsion
        .force('center', d3.forceCenter(width / 2, height / 2))
        .force('link', d3.forceLink(links).id(d => d.Name).distance(250).strength(strength * 0.5)) // Decreased attraction, longer distance
        .force('collide', d3.forceCollide().radius(65));

      const link = g.append('g')
        .attr('stroke', 'var(--secondary-green)')
        .attr('stroke-width', 2)
        .selectAll('line')
        .data(links)
        .enter().append('line');

      const linkLabels = g.append('g')
        .selectAll('text')
        .data(links)
        .enter().append('text')
        .attr('font-size', 12)
        .attr('fill', 'var(--dark-gray)')
        .attr('text-anchor', 'middle')
        .text(d => d.label);

      const node = g.selectAll('g.node')
        .data(people)
        .enter().append('g')
        .attr('class', 'node')
        .call(d3.drag()
          .on('start', dragstarted)
          .on('drag', dragged)
          .on('end', dragended));

      node.append('circle')
        .attr('r', 50)
        .attr('fill', '#b3cde0');

      node.append('image')
        .attr('xlink:href', d => `/images/${d.Image}`)
        .attr('x', -30)
        .attr('y', -30)
        .attr('width', 60)
        .attr('height', 60);

      node.append('text')
        .attr('y', 60)
        .attr('text-anchor', 'middle')
        .text(d => d.Name);

      node.append('title')
        .text(d => `Projects: ${d.Projects}\nTech: ${d.Technologies}\nHobbies: ${d.Hobbies}`);

      simulation.on('tick', () => {
        link
          .attr('x1', d => d.source.x)
          .attr('y1', d => d.source.y)
          .attr('x2', d => d.target.x)
          .attr('y2', d => d.target.y);
        linkLabels
          .attr('x', d => (d.source.x + d.target.x) / 2)
          .attr('y', d => (d.source.y + d.target.y) / 2 - 10)
          .text(d => d.label);
        node.attr('transform', d => `translate(${d.x},${d.y})`);
      });
    }

    // Add event listeners for person bubbles (change from hover to click)
    if (mode === 'hierarchy' || mode === 'projects' || mode === 'technologies') {
      d3.selectAll('g.node').each(function(d) {
        if (d.type === 'person' || d.Hierarchy) {
          d3.select(this)
            .on('click', function(event, datum) {
              if (focusedPerson && focusedPerson === datum) {
                setFocusedPerson(null);
              } else {
                setFocusedPerson(datum);
              }
            });
        }
      });
    }
  }, [people, mode]);

  // Draw focused person overlay (SVG overlay, not JSX)
  useEffect(() => {
    if (!focusedPerson || !svgRef.current) return;
    const svg = d3.select(svgRef.current);
    // Remove any previous overlay
    svg.selectAll('g.focus-overlay').remove();
    // Overlay group
    const overlay = svg.append('g').attr('class', 'focus-overlay');
    // Zoomed circle
    overlay.append('circle')
      .attr('cx', focusedPerson.x)
      .attr('cy', focusedPerson.y)
      .attr('r', 90)
      .attr('fill', 'var(--main-green)')
      .attr('stroke', 'var(--secondary-green)')
      .attr('stroke-width', 6)
      .style('filter', 'drop-shadow(0 0 16px #0006)');
    // Image
    overlay.append('image')
      .attr('xlink:href', `/images/${focusedPerson.Image}`)
      .attr('x', focusedPerson.x - 50)
      .attr('y', focusedPerson.y - 50)
      .attr('width', 100)
      .attr('height', 100)
      .attr('clip-path', 'circle(50px at 50px 50px)');
    // Concentric circles
    overlay.append('circle').attr('cx', focusedPerson.x).attr('cy', focusedPerson.y).attr('r', 120).attr('fill', 'none').attr('stroke', '#fbb4ae').attr('stroke-width', 3);
    overlay.append('circle').attr('cx', focusedPerson.x).attr('cy', focusedPerson.y).attr('r', 150).attr('fill', 'none').attr('stroke', '#b2df8a').attr('stroke-width', 3);
    overlay.append('circle').attr('cx', focusedPerson.x).attr('cy', focusedPerson.y).attr('r', 180).attr('fill', 'none').attr('stroke', '#b3cde0').attr('stroke-width', 3);
    // Projects
    if (focusedPerson.Projects) {
      const arr = focusedPerson.Projects.split(';').map(p => p.trim()).filter(Boolean);
      arr.forEach((proj, i) => {
        overlay.append('text')
          .attr('x', focusedPerson.x + 120 * Math.cos((2 * Math.PI * i) / arr.length - Math.PI/2))
          .attr('y', focusedPerson.y + 120 * Math.sin((2 * Math.PI * i) / arr.length - Math.PI/2))
          .attr('text-anchor', 'middle')
          .attr('alignment-baseline', 'middle')
          .attr('font-size', 16)
          .attr('fill', '#fbb4ae')
          .attr('font-weight', 'bold')
          .text(proj);
      });
    }
    // Technologies
    if (focusedPerson.Technologies) {
      const arr = focusedPerson.Technologies.split(';').map(t => t.trim()).filter(Boolean);
      arr.forEach((tech, i) => {
        overlay.append('text')
          .attr('x', focusedPerson.x + 150 * Math.cos((2 * Math.PI * i) / arr.length - Math.PI/2))
          .attr('y', focusedPerson.y + 150 * Math.sin((2 * Math.PI * i) / arr.length - Math.PI/2))
          .attr('text-anchor', 'middle')
          .attr('alignment-baseline', 'middle')
          .attr('font-size', 15)
          .attr('fill', '#b2df8a')
          .attr('font-weight', 'bold')
          .text(tech);
      });
    }
    // Hobbies
    if (focusedPerson.Hobbies) {
      const arr = focusedPerson.Hobbies.split(';').map(h => h.trim()).filter(Boolean);
      arr.forEach((hobby, i) => {
        overlay.append('text')
          .attr('x', focusedPerson.x + 180 * Math.cos((2 * Math.PI * i) / arr.length - Math.PI/2))
          .attr('y', focusedPerson.y + 180 * Math.sin((2 * Math.PI * i) / arr.length - Math.PI/2))
          .attr('text-anchor', 'middle')
          .attr('alignment-baseline', 'middle')
          .attr('font-size', 14)
          .attr('fill', '#b3cde0')
          .attr('font-weight', 'bold')
          .text(hobby);
      });
    }
    return () => {
      svg.selectAll('g.focus-overlay').remove();
    };
  }, [focusedPerson]);

  return (
    <div style={{ height: '100vh', width: '100vw', overflow: 'hidden', background: 'var(--light-gray)', color: 'var(--dark-gray)' }}>
      <div style={{ position: 'fixed', top: 0, left: 0, height: '100vh', width: 180, background: 'var(--light-gray)', boxShadow: '2px 0 8px #0001', zIndex: 2, display: 'flex', flexDirection: 'column', alignItems: 'center', paddingTop: 40 }}>
        <h2 style={{ marginBottom: 40, fontWeight: 700, letterSpacing: 1, color: 'var(--main-green)' }}>Organigram</h2>
        <button onClick={() => setMode('hierarchy')} style={{ width: '90%', margin: '10px 0', padding: '12px 0', border: 'none', borderRadius: 6, background: mode === 'hierarchy' ? 'var(--main-green)' : 'var(--white)', color: mode === 'hierarchy' ? 'var(--white)' : 'var(--dark-gray)', fontWeight: 600, fontSize: 16, cursor: 'pointer', boxShadow: mode === 'hierarchy' ? '0 2px 8px #7ba80033' : 'none', borderLeft: mode === 'hierarchy' ? '6px solid var(--secondary-green)' : '6px solid transparent', transition: 'background 0.2s, color 0.2s' }}>Hierarchy</button>
        <button onClick={() => setMode('projects')} style={{ width: '90%', margin: '10px 0', padding: '12px 0', border: 'none', borderRadius: 6, background: mode === 'projects' ? 'var(--main-green)' : 'var(--white)', color: mode === 'projects' ? 'var(--white)' : 'var(--dark-gray', fontWeight: 600, fontSize: 16, cursor: 'pointer', boxShadow: mode === 'projects' ? '0 2px 8px #7ba80033' : 'none', borderLeft: mode === 'projects' ? '6px solid var(--secondary-green)' : '6px solid transparent', transition: 'background 0.2s, color 0.2s' }}>Projects</button>
        <button onClick={() => setMode('technologies')} style={{ width: '90%', margin: '10px 0', padding: '12px 0', border: 'none', borderRadius: 6, background: mode === 'technologies' ? 'var(--main-green)' : 'var(--white)', color: mode === 'technologies' ? 'var(--white)' : 'var(--dark-gray)', fontWeight: 600, fontSize: 16, cursor: 'pointer', boxShadow: mode === 'technologies' ? '0 2px 8px #7ba80033' : 'none', borderLeft: mode === 'technologies' ? '6px solid var(--secondary-green)' : '6px solid transparent', transition: 'background 0.2s, color 0.2s' }}>Technologies</button>
      </div>
      <svg ref={svgRef} style={{ position: 'fixed', top: 0, left: 0, width: '100vw', height: '100vh', zIndex: 0, background: 'var(--white)' }}></svg>
      {/* TU Dortmund/FLW logo bottom right */}
      <img
        src="/images/logo.png"
        alt="TU Dortmund/FLW Logo"
        style={{
          position: 'fixed',
          right: 24,
          bottom: 24,
          width: 120,
          height: 'auto',
          zIndex: 10,
          background: 'none',
          borderRadius: 0,
          boxShadow: 'none',
          objectFit: 'contain',
          border: 'none',
          pointerEvents: 'none',
        }}
      />
    </div>
  );
}

export default App;