import { LitElement, html, css } from 'lit';

// Import Tier 1 Class Definitions
// Note: This assumes the build environment supports JSON imports (e.g. Import Attributes or a loader)
import vanguardDef from '../assets/data/classes/vanguard.json' with { type: 'json' };
import weaverDef from '../assets/data/classes/aether_weaver.json' with { type: 'json' };
import scavengerDef from '../assets/data/classes/scavenger.json' with { type: 'json' };
import tinkerDef from '../assets/data/classes/tinker.json' with { type: 'json' };
import custodianDef from '../assets/data/classes/custodian.json' with { type: 'json' };

// UI Metadata Mapping (Data not in the raw engine JSONs)
const CLASS_METADATA = {
  'CLASS_VANGUARD': { 
    icon: '🛡️', 
    image: 'assets/images/portraits/vanguard.png', // Placeholder path
    role: 'Tank',
    description: 'A heavy frontline tank specialized in absorbing damage and protecting allies.' 
  },
  'CLASS_WEAVER': { 
    icon: '✨', 
    image: 'assets/images/portraits/weaver.png',
    role: 'Magic DPS',
    description: 'A master of elemental magic capable of creating powerful synergy chains.' 
  },
  'CLASS_SCAVENGER': { 
    icon: '🎒', 
    image: 'assets/images/portraits/scavenger.png',
    role: 'Utility',
    description: 'Highly mobile utility expert who excels at finding loot and avoiding traps.' 
  },
  'CLASS_TINKER': { 
    icon: '🔧', 
    image: 'assets/images/portraits/tinker.png',
    role: 'Tech',
    description: 'Uses ancient technology to deploy turrets and control the battlefield.' 
  },
  'CLASS_CUSTODIAN': { 
    icon: '🌿', 
    image: 'assets/images/portraits/custodian.png',
    role: 'Healer',
    description: 'A spiritual healer focused on removing corruption and sustaining the squad.' 
  }
};

const RAW_TIER_1_CLASSES = [vanguardDef, weaverDef, scavengerDef, tinkerDef, custodianDef];

export class TeamBuilder extends LitElement {
  static get styles() {
    return css`
      :host {
        display: block;
        position: absolute;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        font-family: 'Courier New', monospace; /* Placeholder for Voxel Font */
        color: white;
        pointer-events: none; /* Let clicks pass through to 3D scene where empty */
        z-index: 10;
        box-sizing: border-box;
      }

      /* Responsive Container Layout */
      .container {
        display: grid;
        grid-template-columns: 280px 1fr 300px; /* Wider side panels on desktop */
        grid-template-rows: 1fr 100px;
        grid-template-areas: 
          "roster squad details"
          "footer footer footer";
        height: 100%;
        width: 100%;
        pointer-events: auto;
        background: rgba(0, 0, 0, 0.6); /* Slightly darker background for readability */
        backdrop-filter: blur(4px);
      }

      /* Mobile Layout (< 1024px) */
      @media (max-width: 1024px) {
        .container {
          grid-template-columns: 1fr;
          grid-template-rows: 200px 1fr 200px 80px; /* Roster, Squad, Details, Footer */
          grid-template-areas: 
            "roster"
            "squad"
            "details"
            "footer";
        }
      }

      /* --- LEFT PANEL: ROSTER --- */
      .roster-panel {
        grid-area: roster;
        background: rgba(20, 20, 30, 0.9);
        border-right: 2px solid #555;
        padding: 1rem;
        overflow-y: auto;
        display: flex;
        flex-direction: column;
        gap: 10px;
      }
      
      @media (max-width: 1024px) {
        .roster-panel {
          flex-direction: row;
          overflow-x: auto;
          overflow-y: hidden;
          border-right: none;
          border-bottom: 2px solid #555;
          align-items: center;
        }
      }

      .class-card {
        background: #333;
        border: 2px solid #555;
        padding: 15px;
        cursor: pointer;
        transition: all 0.2s;
        display: flex;
        align-items: center;
        gap: 15px;
        
        /* Button Reset */
        width: 100%;
        text-align: left;
        font-family: inherit;
        color: inherit;
        appearance: none;
      }

      @media (max-width: 1024px) {
        .class-card {
          width: 200px; /* Fixed width cards for horizontal scroll */
          flex-shrink: 0;
          height: 80%;
        }
      }

      .class-card:hover:not(:disabled) {
        border-color: #00ffff;
        background: #444;
        transform: translateX(5px);
      }
      
      @media (max-width: 1024px) {
         .class-card:hover:not(:disabled) {
            transform: translateY(-5px); /* Hop up on mobile */
         }
      }

      .class-card:disabled {
        opacity: 0.5;
        cursor: not-allowed;
        filter: grayscale(1);
        border-color: #444;
      }

      /* --- CENTER PANEL: SLOTS --- */
      .squad-panel {
        grid-area: squad;
        display: flex;
        justify-content: center;
        align-items: center;
        padding: 2rem;
        gap: 30px;
        flex-wrap: wrap; /* Allow wrapping on very small screens */
        overflow-y: auto;
      }

      /* Wrapper to hold the slot button and the absolute remove button as siblings */
      .slot-wrapper {
        position: relative;
        width: 180px; /* Increased size */
        height: 240px; /* Increased size */
        transition: transform 0.2s;
      }
      
      .slot-wrapper:hover {
        transform: scale(1.05);
      }

      .squad-slot {
        width: 100%;
        height: 100%;
        background: rgba(10, 10, 10, 0.8);
        border: 3px dashed #666;
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        cursor: pointer;
        position: relative;
        overflow: hidden;
        
        /* Button Reset */
        font-family: inherit;
        color: inherit;
        padding: 0;
        appearance: none;
      }
      
      /* Image placeholder style */
      .unit-image {
        width: 100%;
        height: 70%;
        object-fit: cover;
        background-color: #222; /* Fallback */
        border-bottom: 2px solid #555;
      }
      
      .unit-info {
        height: 30%;
        display: flex;
        flex-direction: column;
        justify-content: center;
        align-items: center;
        width: 100%;
        background: rgba(30,30,40,0.9);
      }

      .squad-slot.filled {
        border: 3px solid #00ff00;
        border-style: solid;
        background: rgba(0, 20, 0, 0.8);
      }

      .squad-slot.selected {
        border-color: #00ffff;
        box-shadow: 0 0 20px rgba(0, 255, 255, 0.3);
      }

      .remove-btn {
        position: absolute;
        top: -15px;
        right: -15px;
        background: #cc0000;
        border: 2px solid white;
        color: white;
        width: 32px;
        height: 32px;
        border-radius: 50%;
        cursor: pointer;
        font-weight: bold;
        z-index: 2; /* Ensure it sits on top of the slot button */
        display: flex;
        align-items: center;
        justify-content: center;
        font-size: 1.2rem;
        box-shadow: 2px 2px 5px rgba(0,0,0,0.5);
      }
      
      .remove-btn:hover {
        background: #ff0000;
        transform: scale(1.1);
      }

      /* --- RIGHT PANEL: DETAILS --- */
      .details-panel {
        grid-area: details;
        background: rgba(20, 20, 30, 0.9);
        border-left: 2px solid #555;
        padding: 1.5rem;
        overflow-y: auto;
      }
      
      @media (max-width: 1024px) {
        .details-panel {
          border-left: none;
          border-top: 2px solid #555;
          display: grid;
          grid-template-columns: 1fr 1fr; /* Split content on mobile */
          gap: 20px;
        }
      }

      /* --- FOOTER --- */
      .footer {
        grid-area: footer;
        display: flex;
        justify-content: center;
        align-items: center;
        background: rgba(10, 10, 20, 0.95);
        border-top: 2px solid #555;
      }

      .embark-btn {
        padding: 15px 60px;
        font-size: 1.8rem;
        background: #008800;
        color: white;
        border: 3px solid #00ff00;
        cursor: pointer;
        text-transform: uppercase;
        font-weight: bold;
        font-family: inherit;
        letter-spacing: 2px;
        transition: all 0.2s;
        box-shadow: 0 0 15px rgba(0, 255, 0, 0.2);
      }
      
      .embark-btn:hover:not(:disabled) {
        background: #00aa00;
        box-shadow: 0 0 25px rgba(0, 255, 0, 0.6);
        transform: scale(1.02);
      }

      .embark-btn:disabled {
        background: #333;
        border-color: #555;
        color: #777;
        cursor: not-allowed;
        box-shadow: none;
      }
      
      h2, h3, h4 { margin-top: 0; color: #00ffff; }
      ul { padding-left: 1.2rem; }
      li { margin-bottom: 5px; }
      
      /* Helper for placeholder images */
      .placeholder-img {
        display: flex; 
        align-items: center; 
        justify-content: center; 
        background: #444; 
        color: #888; 
        font-size: 3rem;
      }
    `;
  }

  static get properties() {
    return {
      availableClasses: { type: Array }, // Input: List of class definition objects
      squad: { type: Array }, // Internal State: The 4 slots
      selectedSlotIndex: { type: Number },
      hoveredClass: { type: Object }
    };
  }

  constructor() {
    super();
    this.squad = [null, null, null, null];
    this.selectedSlotIndex = 0; // Default to first slot
    this.hoveredClass = null;

    // Initialize by merging Raw Data with UI Metadata
    this.availableClasses = RAW_TIER_1_CLASSES.map(cls => {
      const meta = CLASS_METADATA[cls.id] || {};
      return {
        ...cls,
        ...meta, // Adds icon, role, description, image path
        unlocked: true // Default all Tier 1s to unlocked
      };
    });
  }

  connectedCallback() {
    super.connectedCallback();
    this._loadMetaProgression();
  }

  /**
   * Loads unlocked classes from persistence (Local Storage / Game State).
   * Merges Tier 2 classes into availableClasses if unlocked.
   */
  _loadMetaProgression() {
    // Mock Implementation: Retrieve unlocked Tier 2 classes from a service or storage
    // In a real implementation, you would import a MetaProgressionManager here.
    
    // Example: const unlockedIds = MetaProgression.getUnlockedClasses();
    const storedData = localStorage.getItem('aether_shards_unlocks');
    if (storedData) {
        try {
            const unlocks = JSON.parse(storedData);
            // This is where you would fetch the full class definition for unlocked Tier 2s 
            // and append them to this.availableClasses
            console.log('Loaded unlocks:', unlocks);
        } catch (e) {
            console.error('Failed to load meta progression', e);
        }
    }
  }

  render() {
    const isSquadValid = this.squad.some(u => u !== null);

    return html`
      <div class="container">
        
        <!-- ROSTER LIST -->
        <div class="roster-panel">
          <h3>Roster</h3>
          ${this.availableClasses.map(cls => html`
            <button 
              type="button"
              class="class-card"
              ?disabled="${!cls.unlocked}"
              @click="${() => this._assignClass(cls)}"
              @mouseenter="${() => this.hoveredClass = cls}"
              @mouseleave="${() => this.hoveredClass = null}"
              aria-label="Select Class: ${cls.name}"
            >
              <div class="icon" style="font-size: 1.5rem;">${cls.icon || '⚔️'}</div>
              <div>
                <strong>${cls.name}</strong><br>
                <small>${cls.role || 'Tier ' + cls.tier}</small>
              </div>
            </button>
          `)}
        </div>

        <!-- CENTER SQUAD SLOTS -->
        <div class="squad-panel">
          ${this.squad.map((unit, index) => html`
            <div class="slot-wrapper">
              <button 
                type="button"
                class="squad-slot ${unit ? 'filled' : ''} ${this.selectedSlotIndex === index ? 'selected' : ''}"
                @click="${() => this._selectSlot(index)}"
                aria-label="${unit ? `Slot ${index + 1}: ${unit.name}` : `Slot ${index + 1}: Empty`}"
                aria-pressed="${this.selectedSlotIndex === index}"
              >
                ${unit 
                  ? html`
                      <!-- Use image property if available, otherwise show large icon placeholder -->
                      ${unit.image 
                        ? html`<img src="${unit.image}" alt="${unit.name}" class="unit-image" onerror="this.style.display='none'; this.nextElementSibling.style.display='flex'">` 
                        : ''
                      }
                      <div class="unit-image placeholder-img" style="${unit.image ? 'display:none' : ''}">
                         ${unit.icon || '🛡️'}
                      </div>
                      
                      <div class="unit-info">
                        <strong>${unit.name}</strong>
                        <small>${this.availableClasses.find(c => c.id === unit.classId)?.role}</small>
                      </div>
                    ` 
                  : html`
                      <div class="placeholder-img" style="background:transparent; color: #555;">+</div>
                      <div class="unit-info" style="background:transparent;">
                        <span>Slot ${index + 1}</span>
                        <small>Empty</small>
                      </div>
                    `
                }
              </button>
              
              ${unit 
                ? html`
                  <button 
                    type="button" 
                    class="remove-btn" 
                    @click="${() => this._removeUnit(index)}"
                    aria-label="Remove ${unit.name} from Slot ${index + 1}"
                  >
                    X
                  </button>` 
                : ''
              }
            </div>
          `)}
        </div>

        <!-- RIGHT DETAILS PANEL -->
        <div class="details-panel">
          ${this.hoveredClass 
            ? html`
                <div>
                  <h2>${this.hoveredClass.name}</h2>
                  <p><em>${this.hoveredClass.role || 'Tier ' + this.hoveredClass.tier} Class</em></p>
                  <hr>
                  <p>${this.hoveredClass.description || 'A skilled explorer ready for the depths.'}</p>
                </div>
                
                <div>
                  <h4>Base Stats</h4>
                  <ul>
                    <li>HP: ${this.hoveredClass.base_stats?.health}</li>
                    <li>Atk: ${this.hoveredClass.base_stats?.attack}</li>
                    <li>Def: ${this.hoveredClass.base_stats?.defense}</li>
                    <li>Mag: ${this.hoveredClass.base_stats?.magic}</li>
                    <li>Spd: ${this.hoveredClass.base_stats?.speed}</li>
                    <li>Will: ${this.hoveredClass.base_stats?.willpower}</li>
                    <li>Move: ${this.hoveredClass.base_stats?.movement}</li>
                    ${this.hoveredClass.base_stats?.tech ? html`<li>Tech: ${this.hoveredClass.base_stats.tech}</li>` : ''}
                  </ul>

                  <h4>Starting Gear</h4>
                  <ul>
                     ${this.hoveredClass.starting_equipment 
                        ? this.hoveredClass.starting_equipment.map(item => html`<li>${this._formatItemName(item)}</li>`) 
                        : html`<li>None</li>`}
                  </ul>
                </div>
              `
            : html`<p>Hover over a class or squad member to see details.</p>`
          }
        </div>

        <!-- FOOTER -->
        <div class="footer">
          <button 
            type="button"
            class="embark-btn" 
            ?disabled="${!isSquadValid}"
            @click="${this._handleEmbark}"
          >
            DESCEND
          </button>
        </div>
      </div>
    `;
  }

  // --- LOGIC ---

  _selectSlot(index) {
    this.selectedSlotIndex = index;
    // If slot has a unit, show its details in hover panel
    if (this.squad[index]) {
        // Need to find the original class ref to show details
        const originalClass = this.availableClasses.find(c => c.id === this.squad[index].classId);
        if (originalClass) this.hoveredClass = originalClass;
    }
  }

  _assignClass(classDef) {
    if (!classDef.unlocked && classDef.unlocked !== undefined) return; // Logic check redundancy for tests without DOM checks

    // 1. Create a lightweight manifest for the slot
    const unitManifest = {
      classId: classDef.id,
      name: classDef.name, // In real app, auto-generate name like "Valerius"
      icon: classDef.icon,
      image: classDef.image // Pass image path
    };

    // 2. Update State (Trigger Re-render)
    const newSquad = [...this.squad];
    newSquad[this.selectedSlotIndex] = unitManifest;
    this.squad = newSquad;

    // 3. Auto-advance selection
    if (this.selectedSlotIndex < 3) {
      this.selectedSlotIndex++;
    }

    // 4. Dispatch Event (For 3D Scene to show model)
    this.dispatchEvent(new CustomEvent('squad-update', {
      detail: { slot: this.selectedSlotIndex, unit: unitManifest },
      bubbles: true,
      composed: true
    }));
  }

  _removeUnit(index) {
    // No stopPropagation needed as elements are siblings now
    const newSquad = [...this.squad];
    newSquad[index] = null;
    this.squad = newSquad;
    this.selectedSlotIndex = index; // Select the empty slot

    // Dispatch Event (To clear 3D model)
    this.dispatchEvent(new CustomEvent('squad-update', {
      detail: { slot: index, unit: null },
      bubbles: true,
      composed: true
    }));
  }

  _handleEmbark() {
    const manifest = this.squad.filter(u => u !== null);
    
    this.dispatchEvent(new CustomEvent('embark', {
      detail: { squad: manifest },
      bubbles: true,
      composed: true
    }));
  }

  // Helpers to make IDs readable (e.g. "ITEM_RUSTY_BLADE" -> "Rusty Blade")
  _formatItemName(id) {
    return id.replace('ITEM_', '').replace(/_/g, ' ').toLowerCase().replace(/\b\w/g, l => l.toUpperCase());
  }

  _formatSkillName(id) {
    return id.replace('SKILL_', '').replace(/_/g, ' ').toLowerCase().replace(/\b\w/g, l => l.toUpperCase());
  }
}

customElements.define('team-builder', TeamBuilder);