import { state, loadMasterDataFromDB } from '../../core/state';
import { createIcons, Search, Monitor, RefreshCw } from 'lucide';
import { API_BASE_URL } from '../../core/utils';

export class PCFlowModal {
  private static instance: PCFlowModal | null = null;

  private modalEl: HTMLElement | null = null;
  private currentFlowType: 'checkout' | 'return' | 'move' = 'checkout';

  // Selected state
  private selectedUser: any = null;
  private selectedTargetUser: any = null;
  private selectedPC: any = null;

  private constructor() {}

  public static getInstance(): PCFlowModal {
    if (!PCFlowModal.instance) {
      PCFlowModal.instance = new PCFlowModal();
    }
    return PCFlowModal.instance;
  }

  public init(onSave: () => void) {
    if (document.getElementById('pc-flow-modal')) return;

    // Inject HTML
    document.body.insertAdjacentHTML('beforeend', this.renderHTML());

    this.modalEl = document.getElementById('pc-flow-modal');
    this.setupEventListeners(onSave);

    // Set default date to today
    const dateInput = document.getElementById('pc-flow-date') as HTMLInputElement;
    if (dateInput) {
      dateInput.value = new Date().toISOString().split('T')[0];
    }

    createIcons({ icons: { Search, Monitor, RefreshCw } });
  }

  public open() {
    this.resetState();
    if (this.modalEl) {
      this.modalEl.classList.remove('hidden');
    }
    this.updateUI();
  }

  public close() {
    if (this.modalEl) {
      this.modalEl.classList.add('hidden');
    }
  }

  private resetState() {
    this.selectedUser = null;
    this.selectedTargetUser = null;
    this.selectedPC = null;
    this.currentFlowType = 'checkout';

    const radioCheckout = document.querySelector('input[name="flow-type"][value="checkout"]') as HTMLInputElement;
    if (radioCheckout) {
        radioCheckout.checked = true;
        document.querySelectorAll('.flow-type-label').forEach(l => {
            l.classList.toggle('active', l.contains(radioCheckout));
        });
    }

    // Reset text fields
    const userSearch = document.getElementById('pc-flow-user-search') as HTMLInputElement;
    if (userSearch) userSearch.value = '';

    const targetUserSearch = document.getElementById('pc-flow-target-user-search') as HTMLInputElement;
    if (targetUserSearch) targetUserSearch.value = '';

    const stockSearch = document.getElementById('pc-flow-stock-search') as HTMLInputElement;
    if (stockSearch) stockSearch.value = '';

    const details = document.getElementById('pc-flow-details') as HTMLTextAreaElement;
    if (details) details.value = '';
  }

  private setupEventListeners(onSave: () => void) {
    const btnClose = document.getElementById('btn-close-pc-flow-modal');
    const btnCancel = document.getElementById('btn-cancel-pc-flow-modal');
    const btnSubmit = document.getElementById('btn-submit-pc-flow');

    btnClose?.addEventListener('click', () => this.close());
    btnCancel?.addEventListener('click', () => this.close());

    // Flow Type Radio Buttons
    const labels = document.querySelectorAll('.flow-type-label');
    labels.forEach(label => {
      const radio = label.querySelector('input[name="flow-type"]') as HTMLInputElement;
      label.addEventListener('click', () => {
        labels.forEach(l => l.classList.remove('active'));
        label.classList.add('active');
        radio.checked = true;
        this.currentFlowType = radio.value as any;

        // Reset selected PC when switching flow types
        this.selectedPC = null;
        this.updateUI();
      });
    });

    // 1. Source User Autocomplete Search
    const userSearch = document.getElementById('pc-flow-user-search') as HTMLInputElement;
    const userSuggestions = document.getElementById('pc-flow-user-suggestions')!;

    userSearch?.addEventListener('input', () => {
      const query = userSearch.value.trim().toLowerCase();
      if (!query) {
        userSuggestions.classList.add('hidden');
        return;
      }

      const users = state.masterData.users || [];
      const filtered = users.filter((u: any) =>
        (u.user_name && u.user_name.toLowerCase().includes(query)) ||
        (u.dept_name && u.dept_name.toLowerCase().includes(query)) ||
        (u.emp_no && u.emp_no.toString().includes(query))
      );

      const uniqueFiltered: any[] = [];
      const seen = new Set();
      filtered.forEach((u: any) => {
        const key = u.emp_no || u.user_name;
        if (!seen.has(key)) {
          seen.add(key);
          uniqueFiltered.push(u);
        }
      });

      this.renderUserSuggestions(uniqueFiltered, userSuggestions, (user) => {
        this.selectedUser = user;
        userSearch.value = `${user.user_name} (${user.dept_name} / 사번:${user.emp_no || '-'})`;
        userSuggestions.classList.add('hidden');

        // Automatically populate details if return or move
        if (this.currentFlowType === 'return' || this.currentFlowType === 'move') {
          this.selectedPC = null; // Reset selection
        }
        this.updateUI();
      });
    });

    // Close suggestion overlays on clicking outside
    document.addEventListener('click', (e) => {
      const target = e.target as HTMLElement;
      if (!target.closest('#pc-flow-user-search') && !target.closest('#pc-flow-user-suggestions')) {
        userSuggestions.classList.add('hidden');
      }
      if (!target.closest('#pc-flow-target-user-search') && !target.closest('#pc-flow-target-user-suggestions')) {
        const targetSuggestions = document.getElementById('pc-flow-target-user-suggestions');
        targetSuggestions?.classList.add('hidden');
      }
      if (!target.closest('#pc-flow-stock-search') && !target.closest('#pc-flow-stock-suggestions')) {
        const stockSuggestions = document.getElementById('pc-flow-stock-suggestions');
        stockSuggestions?.classList.add('hidden');
      }
    });

    // 2. Target User Autocomplete Search (For Moves)
    const targetUserSearch = document.getElementById('pc-flow-target-user-search') as HTMLInputElement;
    const targetSuggestions = document.getElementById('pc-flow-target-user-suggestions')!;

    targetUserSearch?.addEventListener('input', () => {
      const query = targetUserSearch.value.trim().toLowerCase();
      if (!query) {
        targetSuggestions.classList.add('hidden');
        return;
      }

      const users = state.masterData.users || [];
      const filtered = users.filter((u: any) =>
        (u.user_name && u.user_name.toLowerCase().includes(query)) ||
        (u.dept_name && u.dept_name.toLowerCase().includes(query)) ||
        (u.emp_no && u.emp_no.toString().includes(query))
      );

      const uniqueFiltered: any[] = [];
      const seen = new Set();
      filtered.forEach((u: any) => {
        const key = u.emp_no || u.user_name;
        if (!seen.has(key)) {
          seen.add(key);
          uniqueFiltered.push(u);
        }
      });

      this.renderUserSuggestions(uniqueFiltered, targetSuggestions, (user) => {
        this.selectedTargetUser = user;
        targetUserSearch.value = `${user.user_name} (${user.dept_name} / 사번:${user.emp_no || '-'})`;
        targetSuggestions.classList.add('hidden');
        this.updateUI();
      });
    });

    // 3. Stock PC Autocomplete Search (For Checkout)
    const stockSearch = document.getElementById('pc-flow-stock-search') as HTMLInputElement;
    const stockSuggestions = document.getElementById('pc-flow-stock-suggestions')!;

    const showStockSuggestions = () => {
      const query = stockSearch.value.trim().toLowerCase();

      // Filter available PCs (category PC, status '대기', '미할당', or '재고')
      const pcs = state.masterData.pc || [];
      const filtered = pcs.filter((p: any) => {
        const status = (p.hw_status || '').trim();
        const matchesQuery = !query ||
          (p.asset_code && p.asset_code.toLowerCase().includes(query)) ||
          (p.model_name && p.model_name.toLowerCase().includes(query)) ||
          (p.cpu && p.cpu.toLowerCase().includes(query));

        return (status === '대기' || status === '미할당' || status === '재고') && matchesQuery;
      });

      this.renderPCSuggestions(filtered, stockSuggestions, (pc) => {
        this.selectedPC = pc;
        stockSearch.value = `${pc.asset_code} - ${pc.model_name}`;
        stockSuggestions.classList.add('hidden');
        this.updateUI();
      });
    };

    stockSearch?.addEventListener('input', showStockSuggestions);
    stockSearch?.addEventListener('focus', showStockSuggestions);
    stockSearch?.addEventListener('click', showStockSuggestions);

    // 4. Submit Transaction
    btnSubmit?.addEventListener('click', async () => {
      if (!this.validateInputs()) return;

      const dateVal = (document.getElementById('pc-flow-date') as HTMLInputElement).value;
      const detailsVal = (document.getElementById('pc-flow-details') as HTMLTextAreaElement).value.trim();
      const loginUser = state.currentUserRole === 'admin' ? '관리자' : '실무담당자';

      // Build Details Message as JSON
      const logData = {
        type: this.currentFlowType,
        user: this.selectedUser ? this.selectedUser.user_name : '',
        dept: this.selectedUser ? this.selectedUser.dept_name : '',
        targetUser: this.selectedTargetUser ? this.selectedTargetUser.user_name : '',
        targetDept: this.selectedTargetUser ? this.selectedTargetUser.dept_name : '',
        assetCode: this.selectedPC ? this.selectedPC.asset_code : '',
        memo: detailsVal
      };
      const finalDetails = JSON.stringify(logData);

      const payload: any = {
        action: this.currentFlowType,
        assetId: this.selectedPC.id,
        date: dateVal,
        details: finalDetails,
        manager: loginUser
      };

      if (this.currentFlowType === 'checkout') {
        payload.userName = this.selectedUser.user_name;
        payload.dept = this.selectedUser.dept_name;
        payload.empNo = this.selectedUser.emp_no;
        payload.position = this.selectedUser.position || '사원';
      } else if (this.currentFlowType === 'move') {
        payload.userName = this.selectedTargetUser.user_name;
        payload.dept = this.selectedTargetUser.dept_name;
        payload.empNo = this.selectedTargetUser.emp_no;
        payload.position = this.selectedTargetUser.position || '사원';
      }

      try {
        const response = await fetch(`${API_BASE_URL}/api/pc/flow`, {
          method: 'POST',
          headers: { 'Content-Type': 'application/json' },
          body: JSON.stringify(payload)
        });

        if (response.ok) {
          alert('PC 이동/반납 처리가 완료되었습니다.');
          this.close();
          onSave(); // Refresh views
        } else {
          const errData = await response.json();
          alert(`오류 발생: ${errData.error || '처리 실패'}`);
        }
      } catch (err) {
        console.error('API Error:', err);
        alert('서버 전송 중 오류가 발생했습니다.');
      }
    });
  }

  private validateInputs(): boolean {
    if (this.currentFlowType === 'checkout') {
      if (!this.selectedUser) { alert('대상 사원을 선택해주세요.'); return false; }
      if (!this.selectedPC) { alert('불출할 재고 PC를 선택해주세요.'); return false; }
    } else if (this.currentFlowType === 'return') {
      if (!this.selectedUser) { alert('반납 대상 사원을 선택해주세요.'); return false; }
      if (!this.selectedPC) { alert('반납할 PC 자산을 선택해주세요.'); return false; }
    } else if (this.currentFlowType === 'move') {
      if (!this.selectedUser) { alert('인계 사원을 선택해주세요.'); return false; }
      if (!this.selectedPC) { alert('이동할 PC 자산을 선택해주세요.'); return false; }
      if (!this.selectedTargetUser) { alert('인수 사원을 선택해주세요.'); return false; }
      if (this.selectedUser.emp_no === this.selectedTargetUser.emp_no) {
        alert('인계자와 인수자는 동일할 수 없습니다.');
        return false;
      }
    }
    return true;
  }

  private renderUserSuggestions(users: any[], container: HTMLElement, onSelect: (user: any) => void) {
    container.innerHTML = '';
    if (users.length === 0) {
      container.innerHTML = '<div class="autocomplete-item-empty">일치하는 사원이 없습니다.</div>';
      container.classList.remove('hidden');
      return;
    }

    users.forEach(u => {
      const item = document.createElement('div');
      item.className = 'autocomplete-item';
      item.innerHTML = `
        <div class="suggestion-name">${u.user_name}</div>
        <div class="suggestion-meta">
          <span>부서: ${u.dept_name}</span>
          <span>|</span>
          <span>사번: ${u.emp_no || '-'}</span>
        </div>
      `;
      item.addEventListener('click', () => onSelect(u));
      container.appendChild(item);
    });
    container.classList.remove('hidden');
  }

  private renderPCSuggestions(pcs: any[], container: HTMLElement, onSelect: (pc: any) => void) {
    container.innerHTML = '';
    if (pcs.length === 0) {
      container.innerHTML = '<div class="autocomplete-item-empty">불출 가능한 대기 PC 재고가 없습니다.</div>';
      container.classList.remove('hidden');
      return;
    }

    pcs.forEach(p => {
      const item = document.createElement('div');
      item.className = 'autocomplete-item';
      item.innerHTML = `
        <div class="suggestion-name">${p.asset_code} (${p.model_name || '모델명 없음'})</div>
        <div class="suggestion-meta">
          사양: CPU ${p.cpu || '-'} / RAM ${p.ram || '-'} / 위치: ${p.location || '-'}
        </div>
      `;
      item.addEventListener('click', () => onSelect(p));
      container.appendChild(item);
    });
    container.classList.remove('hidden');
  }

  private updateUI() {
    // 1. Hide/Show dynamic sections based on flow type
    const stockContainer = document.getElementById('stock-pc-search-container')!;
    const targetUserContainer = document.getElementById('target-user-search-container')!;
    const userPcsContainer = document.getElementById('user-pcs-container')!;
    const labelStep2 = document.getElementById('user-search-label')!;

    if (this.currentFlowType === 'checkout') {
      stockContainer.classList.remove('hidden');
      targetUserContainer.classList.add('hidden');
      userPcsContainer.classList.add('hidden');
      labelStep2.textContent = '2. 불출 대상 사원 검색';
    } else if (this.currentFlowType === 'return') {
      stockContainer.classList.add('hidden');
      targetUserContainer.classList.add('hidden');
      userPcsContainer.classList.remove('hidden');
      labelStep2.textContent = '2. 반납 대상 사원 검색';
    } else if (this.currentFlowType === 'move') {
      stockContainer.classList.add('hidden');
      targetUserContainer.classList.remove('hidden');
      userPcsContainer.classList.remove('hidden');
      labelStep2.textContent = '2. 인계 사원 검색';
    }

    // 2. Update summary panels on the right
    const summaryUserName = document.getElementById('summary-user-name')!;
    const summaryUserDept = document.getElementById('summary-user-dept')!;
    if (this.selectedUser) {
      summaryUserName.textContent = this.selectedUser.user_name;
      summaryUserDept.textContent = `${this.selectedUser.dept_name} / 사번: ${this.selectedUser.emp_no || '-'}`;
    } else {
      summaryUserName.textContent = '선택된 사원 없음';
      summaryUserDept.textContent = '-';
    }

    const summaryTargetCard = document.getElementById('summary-target-user-card')!;
    const summaryTargetUserName = document.getElementById('summary-target-user-name')!;
    const summaryTargetUserDept = document.getElementById('summary-target-user-dept')!;
    if (this.currentFlowType === 'move') {
      summaryTargetCard.classList.remove('hidden');
      if (this.selectedTargetUser) {
        summaryTargetUserName.textContent = this.selectedTargetUser.user_name;
        summaryTargetUserDept.textContent = `${this.selectedTargetUser.dept_name} / 사번: ${this.selectedTargetUser.emp_no || '-'}`;
      } else {
        summaryTargetUserName.textContent = '선택된 사원 없음';
        summaryTargetUserDept.textContent = '-';
      }
    } else {
      summaryTargetCard.classList.add('hidden');
    }

    const summaryPcCode = document.getElementById('summary-pc-code')!;
    const summaryPcModel = document.getElementById('summary-pc-model')!;
    if (this.selectedPC) {
      summaryPcCode.textContent = this.selectedPC.asset_code;
      summaryPcModel.textContent = `${this.selectedPC.model_name || '모델명 없음'} (${this.selectedPC.cpu || '-'} / ${this.selectedPC.ram || '-'})`;
    } else {
      summaryPcCode.textContent = '선택된 PC 없음';
      summaryPcModel.textContent = '-';
    }

    // 3. Render user's active PCs list on the right (For Return & Move)
    const userPcsList = document.getElementById('user-pcs-list')!;
    if (this.selectedUser && (this.currentFlowType === 'return' || this.currentFlowType === 'move')) {
      const allPcs = state.masterData.pc || [];
      const userPcs = allPcs.filter((p: any) =>
        (p.emp_no && p.emp_no.toString() === this.selectedUser.emp_no?.toString()) ||
        (p.user_current && p.user_current === this.selectedUser.user_name)
      );

      if (userPcs.length === 0) {
        userPcsList.innerHTML = '<div class="empty-list-message">이 사용자가 소유한 PC 자산이 없습니다.</div>';
      } else {
        userPcsList.innerHTML = userPcs.map(p => {
          const isSelected = this.selectedPC && this.selectedPC.id === p.id;
          return `
            <div class="user-pc-item ${isSelected ? 'selected' : ''}" data-id="${p.id}">
              <div class="pc-item-code">${p.asset_code}</div>
              <div class="pc-item-meta">
                ${p.model_name || '모델명 없음'} | CPU: ${p.cpu || '-'} | RAM: ${p.ram || '-'}
              </div>
            </div>
          `;
        }).join('');

        // Bind clicks to list items
        userPcsList.querySelectorAll('.user-pc-item').forEach(item => {
          item.addEventListener('click', () => {
            const pcId = item.getAttribute('data-id');
            const foundPC = userPcs.find(p => p.id === pcId);
            if (foundPC) {
              this.selectedPC = foundPC;
              this.updateUI();
            }
          });
        });
      }
    } else {
      userPcsList.innerHTML = '';
    }
  }

  private renderHTML(): string {
    return `
      <div id="pc-flow-modal" class="modal-overlay hidden">
        <div class="modal-content wide">
          <div class="modal-header">
            <h2 class="modal-title">
              <i data-lucide="refresh-cw"></i> PC 이동/반납 (불출/반납/이동)
            </h2>
            <button id="btn-close-pc-flow-modal" class="btn-icon" aria-label="닫기">&times;</button>
          </div>

          <div class="modal-body">
            <div class="modal-body-split">
              <!-- 왼쪽 영역: 입력 폼 -->
              <div class="modal-form-area">
                <div class="grid-form flex-col">

                  <!-- 1. 처리 유형 -->
                  <div class="form-group">
                    <label>1. 처리 유형 선택</label>
                    <div class="view-toggle w-full flex-row">
                      <label class="flow-type-label toggle-btn active flex-1 text-center">
                        <input type="radio" name="flow-type" value="checkout" checked class="hidden" />
                        불출 (지급)
                      </label>
                      <label class="flow-type-label toggle-btn flex-1 text-center">
                        <input type="radio" name="flow-type" value="return" class="hidden" />
                        입고 (반납)
                      </label>
                      <label class="flow-type-label toggle-btn flex-1 text-center">
                        <input type="radio" name="flow-type" value="move" class="hidden" />
                        이동 (이관)
                      </label>
                    </div>
                  </div>

                  <!-- 2. 대상 사용자 검색 -->
                  <div class="form-group relative">
                    <label id="user-search-label">2. 대상 사원 검색</label>
                    <div class="input-with-icon">
                      <input type="text" id="pc-flow-user-search" placeholder="사원명, 부서, 사번 검색..." />
                      <i data-lucide="search" class="icon-sm"></i>
                    </div>
                    <div id="pc-flow-user-suggestions" class="autocomplete-list hidden"></div>
                  </div>

                  <!-- 3. 새 인수자 검색 (이동 시 노출) -->
                  <div id="target-user-search-container" class="form-group hidden relative">
                    <label>새 인수 사원 검색</label>
                    <div class="input-with-icon">
                      <input type="text" id="pc-flow-target-user-search" placeholder="사원명, 부서, 사번 검색..." />
                      <i data-lucide="search" class="icon-sm"></i>
                    </div>
                    <div id="pc-flow-target-user-suggestions" class="autocomplete-list hidden"></div>
                  </div>

                  <!-- 4. 재고 PC 검색 (불출 시 노출) -->
                  <div id="stock-pc-search-container" class="form-group relative">
                    <label>3. 불출할 재고 PC 선택</label>
                    <div class="input-with-icon">
                      <input type="text" id="pc-flow-stock-search" placeholder="자산코드 또는 모델명 검색..." />
                      <i data-lucide="monitor" class="icon-sm"></i>
                    </div>
                    <div id="pc-flow-stock-suggestions" class="autocomplete-list hidden"></div>
                  </div>

                  <!-- 5. 상세 공통 입력 -->
                  <div class="detail-grid-2col">
                    <div class="form-group">
                      <label>처리 일자</label>
                      <input type="date" id="pc-flow-date" />
                    </div>
                    <div class="form-group">
                      <label>상세 사유</label>
                      <textarea id="pc-flow-details" rows="2" placeholder="미입력 시 기본 문구로 자동 입력됩니다."></textarea>
                    </div>
                  </div>
                </div>
              </div>

              <!-- 오른쪽 영역: 선택 요약 & 사원 소유 자산 목록 -->
              <div class="modal-history-area">
                <div class="history-header">
                  <h3>선택 내역 요약</h3>
                </div>

                <div class="dynamic-row-container">
                  <!-- 사원 요약 카드 -->
                  <div id="summary-user-card" class="summary-info-card">
                    <div class="detail-label-sm">대상 사원</div>
                    <div id="summary-user-name" class="detail-value-lg">선택된 사원 없음</div>
                    <div id="summary-user-dept" class="detail-label-sm">-</div>
                  </div>

                  <!-- 인수 사원 요약 카드 (이동 전용) -->
                  <div id="summary-target-user-card" class="summary-info-card hidden bg-primary-light">
                    <div class="detail-label-sm">새 인수 사원</div>
                    <div id="summary-target-user-name" class="detail-value-lg">선택된 사원 없음</div>
                    <div id="summary-target-user-dept" class="detail-label-sm">-</div>
                  </div>

                  <!-- 대상 PC 자산 요약 카드 -->
                  <div id="summary-pc-card" class="summary-info-card">
                    <div class="detail-label-sm">대상 PC 자산</div>
                    <div id="summary-pc-code" class="detail-value-lg text-success">선택된 PC 없음</div>
                    <div id="summary-pc-model" class="detail-label-sm">-</div>
                  </div>

                  <!-- 사용자 보유 PC 목록 선택 (반납/이동 시) -->
                  <div id="user-pcs-container" class="form-group hidden">
                    <label>사원 보유 PC 선택 (클릭하여 매핑)</label>
                    <div id="user-pcs-list" class="user-pc-selection-list"></div>
                  </div>
                </div>
              </div>
            </div>
          </div>

          <div class="modal-footer">
            <div></div>
            <div class="footer-actions">
              <button id="btn-cancel-pc-flow-modal" class="btn btn-outline">취소</button>
              <button id="btn-submit-pc-flow" class="btn btn-primary">이동/반납 처리 완료</button>
            </div>
          </div>
        </div>
      </div>
    `;
  }
}

export const pcFlowModal = PCFlowModal.getInstance();