<template>
  <div class="excel-accounting-section" v-if="entries.length > 0 || loading">
    <div class="section-header">
      <h2>Excel-pohjan Kirjanpito</h2>
      <div class="header-actions">
        <button class="btn btn-primary" @click="showAddEntryModal">
          <i class="fas fa-plus"></i> Lisää Tapahtuma
        </button>
        <button class="btn btn-secondary" @click="exportToExcel">
          <i class="fas fa-download"></i> Vie Excel
        </button>
      </div>
    </div>

    <!-- Filters -->
    <div class="filters">
      <div class="filter-group">
        <label for="dateFilter">Päivämäärä:</label>
        <input 
          type="date" 
          id="dateFilter" 
          v-model="filters.date" 
          @change="applyFilters"
        >
      </div>
      <div class="filter-group">
        <label for="typeFilter">Tyyppi:</label>
        <select id="typeFilter" v-model="filters.type" @change="applyFilters">
          <option value="">Kaikki</option>
          <option value="Tulo">Tulo</option>
          <option value="Kulu">Kulu</option>
        </select>
      </div>
      <div class="filter-group">
        <label for="categoryFilter">Luokka:</label>
        <input 
          type="text" 
          id="categoryFilter" 
          v-model="filters.category" 
          placeholder="Hae luokasta..."
          @input="applyFilters"
        >
      </div>
    </div>

    <!-- Summary Cards -->
    <div class="summary-cards">
      <div class="summary-card income">
        <h3>Tulot</h3>
        <p class="amount">{{ formatCurrency(totalIncome) }}</p>
      </div>
      <div class="summary-card expenses">
        <h3>Kulut</h3>
        <p class="amount">{{ formatCurrency(totalExpenses) }}</p>
      </div>
      <div class="summary-card balance" :class="{ 'positive': netBalance >= 0, 'negative': netBalance < 0 }">
        <h3>Saldo</h3>
        <p class="amount">{{ formatCurrency(netBalance) }}</p>
      </div>
    </div>

    <!-- Entries Table -->
    <div class="entries-section">
      <div v-if="loading" class="loading">
        Ladataan tapahtumia...
      </div>
      
      <div v-else-if="filteredEntries.length === 0" class="no-data">
        Ei tapahtumia löytynyt.
      </div>
      
      <table v-else class="table">
        <thead>
          <tr>
            <th>Päivämäärä</th>
            <th>Kuvaus</th>
            <th>Tyyppi</th>
            <th>Luokka</th>
            <th>Veroton summa</th>
            <th>ALV %</th>
            <th>ALV 25,5%</th>
            <th>ALV 14%</th>
            <th>ALV 10%</th>
            <th>Yhteensä</th>
            <th>Netto</th>
            <th>ALV</th>
            <th>Viite</th>
            <th>Toiminnot</th>
          </tr>
        </thead>
        <tbody>
          <tr v-for="entry in paginatedEntries" :key="entry.id" :class="{ 'income': entry.entry_type === 'Tulo', 'expense': entry.entry_type === 'Kulu' }">
            <td>{{ formatDate(entry.entry_date) }}</td>
            <td>{{ entry.description }}</td>
            <td>
              <span :class="['entry-type-badge', entry.entry_type.toLowerCase()]">
                {{ entry.entry_type }}
              </span>
            </td>
            <td>{{ entry.category || '-' }}</td>
            <td class="currency">{{ formatCurrency(entry.tax_free_amount) }}</td>
            <td class="percentage">{{ entry.vat_percentage }}%</td>
            <td class="currency">{{ formatCurrency(entry.vat_25_5) }}</td>
            <td class="currency">{{ formatCurrency(entry.vat_14) }}</td>
            <td class="currency">{{ formatCurrency(entry.vat_10) }}</td>
            <td class="currency">{{ formatCurrency(entry.total_amount) }}</td>
            <td class="currency">{{ formatCurrency(entry.net_amount) }}</td>
            <td class="currency">{{ formatCurrency(entry.vat_amount) }}</td>
            <td>{{ entry.reference_number || '-' }}</td>
            <td>
              <div class="actions">
                <button class="btn btn-sm btn-primary" @click="editEntry(entry)">Muokkaa</button>
                <button class="btn btn-sm btn-danger" @click="deleteEntry(entry.id)">Poista</button>
              </div>
            </td>
          </tr>
        </tbody>
      </table>

      <!-- Pagination -->
      <div class="pagination" v-if="totalPages > 1">
        <button 
          class="btn btn-secondary" 
          @click="currentPage--" 
          :disabled="currentPage <= 1"
        >
          Edellinen
        </button>
        <span class="page-info">Sivu {{ currentPage }} / {{ totalPages }}</span>
        <button 
          class="btn btn-secondary" 
          @click="currentPage++" 
          :disabled="currentPage >= totalPages"
        >
          Seuraava
        </button>
      </div>
    </div>

    <!-- Add/Edit Entry Modal -->
    <div v-if="showEntryModal" class="modal" @click.self="closeEntryModal">
      <div class="modal-content">
        <span class="close" @click="closeEntryModal">&times;</span>
        <h2>{{ isEditingEntry ? 'Muokkaa Tapahtumaa' : 'Lisää Tapahtuma' }}</h2>
        
        <form @submit.prevent="saveEntry">
          <div class="form-row">
            <div class="form-group">
              <label for="entry_date">Päivämäärä *</label>
              <input 
                type="date" 
                id="entry_date" 
                v-model="entryForm.entry_date" 
                required
              >
            </div>
            <div class="form-group">
              <label for="entry_type">Tyyppi *</label>
              <select id="entry_type" v-model="entryForm.entry_type" @change="onEntryTypeChange" required>
                <option value="">Valitse tyyppi</option>
                <option value="Tulo">Tulo</option>
                <option value="Kulu">Kulu</option>
              </select>
            </div>
          </div>

          <div class="form-group">
            <label for="description">Kuvaus *</label>
            <textarea 
              id="description" 
              v-model="entryForm.description" 
              required
              placeholder="Syötä tapahtuman kuvaus..."
            ></textarea>
          </div>

          <div class="form-group">
            <label for="category">Luokka</label>
            <select 
              id="category" 
              v-model="entryForm.category" 
              @change="onCategoryChange"
            >
              <option value="">Valitse luokka</option>
              <option v-for="cat in availableCategories" :key="cat.code" :value="cat.code">
                {{ cat.name }}
              </option>
            </select>
          </div>

          <div class="form-row">
            <div class="form-group">
              <label for="tax_free_amount">Veroton summa</label>
              <input 
                type="number" 
                id="tax_free_amount" 
                v-model="entryForm.tax_free_amount" 
                step="0.01"
                min="0"
                @input="calculateTotals"
              >
            </div>
            <div class="form-group">
              <label for="vat_percentage">ALV %</label>
              <select id="vat_percentage" v-model="entryForm.vat_percentage" @change="calculateTotals">
                <option value="0">0%</option>
                <option value="10">10%</option>
                <option value="14">14%</option>
                <option value="25.5">25.5%</option>
              </select>
            </div>
          </div>

          <div class="form-row">
            <div class="form-group">
              <label for="total_amount">Yhteensä *</label>
              <input 
                type="number" 
                id="total_amount" 
                v-model="entryForm.total_amount" 
                step="0.01"
                required
                @input="calculateVAT"
              >
            </div>
            <div class="form-group">
              <label for="reference_number">Viitenumero</label>
              <input 
                type="text" 
                id="reference_number" 
                v-model="entryForm.reference_number" 
                placeholder="Viitenumero..."
              >
            </div>
          </div>

          <div class="form-actions">
            <button type="button" class="btn" @click="closeEntryModal">Peruuta</button>
            <button type="submit" class="btn btn-success">
              {{ isEditingEntry ? 'Päivitä' : 'Tallenna' }}
            </button>
          </div>
        </form>
      </div>
    </div>
  </div>
</template>

<script>
import api from '../../api/axios'
import { formatCurrency, formatDate } from '../../utils/locale'

export default {
  name: 'ExcelAccountingSection',
  emits: ['add-entry', 'edit-entry', 'delete-entry'],
  data() {
    return {
      entries: [],
      loading: false,
      showEntryModal: false,
      isEditingEntry: false,
      currentPage: 1,
      itemsPerPage: 50,
      categories: [],
      categoriesLoading: false,
      filters: {
        date: '',
        type: '',
        category: ''
      },
      entryForm: {
        id: null,
        entry_date: '',
        description: '',
        entry_type: '',
        category: '',
        tax_free_amount: 0,
        vat_percentage: 24,
        vat_25_5: 0,
        vat_14: 0,
        vat_10: 0,
        total_amount: 0,
        net_amount: 0,
        vat_amount: 0,
        reference_number: ''
      }
    }
  },
  computed: {
    availableCategories() {
      if (!this.entryForm.entry_type) {
        return []
      }
      return this.categories.filter(cat => cat.type === this.entryForm.entry_type)
    },
    filteredEntries() {
      let filtered = this.entries
      
      if (this.filters.date) {
        filtered = filtered.filter(entry => entry.entry_date >= this.filters.date)
      }
      
      if (this.filters.type) {
        filtered = filtered.filter(entry => entry.entry_type === this.filters.type)
      }
      
      if (this.filters.category) {
        filtered = filtered.filter(entry => 
          entry.category && entry.category.toLowerCase().includes(this.filters.category.toLowerCase())
        )
      }
      
      return filtered
    },
    paginatedEntries() {
      const start = (this.currentPage - 1) * this.itemsPerPage
      const end = start + this.itemsPerPage
      return this.filteredEntries.slice(start, end)
    },
    totalPages() {
      return Math.ceil(this.filteredEntries.length / this.itemsPerPage)
    },
    totalIncome() {
      return this.filteredEntries
        .filter(entry => entry.entry_type === 'Tulo')
        .reduce((sum, entry) => sum + parseFloat(entry.total_amount || 0), 0)
    },
    totalExpenses() {
      return this.filteredEntries
        .filter(entry => entry.entry_type === 'Kulu')
        .reduce((sum, entry) => sum + parseFloat(entry.total_amount || 0), 0)
    },
    netBalance() {
      return this.totalIncome - this.totalExpenses
    }
  },
  methods: {
    formatCurrency,
    formatDate,
    async fetchEntries() {
      this.loading = true
      try {
        const response = await api.get('/accounting_entries.php')
        this.entries = response.data.records || []
      } catch (error) {
        console.error('Error fetching entries:', error)
      } finally {
        this.loading = false
      }
    },
    async fetchCategories() {
      this.categoriesLoading = true
      try {
        const response = await api.get('/accounting_categories.php')
        this.categories = response.data || []
      } catch (error) {
        console.error('Error fetching categories:', error)
      } finally {
        this.categoriesLoading = false
      }
    },
    showAddEntryModal() {
      this.isEditingEntry = false
      this.entryForm = {
        id: null,
        entry_date: new Date().toISOString().split('T')[0],
        description: '',
        entry_type: '',
        category: '',
        tax_free_amount: 0,
        vat_percentage: 24,
        vat_25_5: 0,
        vat_14: 0,
        vat_10: 0,
        total_amount: 0,
        net_amount: 0,
        vat_amount: 0,
        reference_number: ''
      }
      this.showEntryModal = true
    },
    onCategoryChange() {
      // Automatically set VAT percentage based on selected category
      if (this.entryForm.category) {
        const selectedCategory = this.categories.find(cat => cat.code === this.entryForm.category)
        if (selectedCategory) {
          this.entryForm.vat_percentage = parseFloat(selectedCategory.vat_percentage) || 0
          // Always calculate VAT when category changes to show the calculation
          this.calculateVAT()
        }
      }
    },
    onEntryTypeChange() {
      // Clear category when entry type changes
      this.entryForm.category = ''
    },
    editEntry(entry) {
      this.isEditingEntry = true
      this.entryForm = { ...entry }
      this.showEntryModal = true
    },
    closeEntryModal() {
      this.showEntryModal = false
      this.entryForm = {
        id: null,
        entry_date: '',
        description: '',
        entry_type: '',
        category: '',
        tax_free_amount: 0,
        vat_percentage: 24,
        vat_25_5: 0,
        vat_14: 0,
        vat_10: 0,
        total_amount: 0,
        net_amount: 0,
        vat_amount: 0,
        reference_number: ''
      }
    },
    calculateVAT() {
      const vatRate = parseFloat(this.entryForm.vat_percentage) || 0
      const total = parseFloat(this.entryForm.total_amount) || 0
      
      if (vatRate === 25.5) {
        // Yhteensä = Verollinen vero (Brutto ÷ 1.255)
        this.entryForm.vat_25_5 = total * 0.255 / 1.255
        this.entryForm.vat_14 = 0
        this.entryForm.vat_10 = 0
      } else if (vatRate === 14) {
        // Yhteensä = Verollinen vero (Brutto ÷ 1.14)
        this.entryForm.vat_25_5 = 0
        this.entryForm.vat_14 = total * 0.14 / 1.14
        this.entryForm.vat_10 = 0
      } else if (vatRate === 10) {
        // Yhteensä = Verollinen vero (Brutto ÷ 1.10)
        this.entryForm.vat_25_5 = 0
        this.entryForm.vat_14 = 0
        this.entryForm.vat_10 = total * 0.10 / 1.10
      } else {
        // Yhteensä = Verollinen vero (Brutto ÷ 1.24)
        this.entryForm.vat_25_5 = 0
        this.entryForm.vat_14 = 0
        this.entryForm.vat_10 = 0
      }
      
      this.entryForm.vat_amount = this.entryForm.vat_25_5 + this.entryForm.vat_14 + this.entryForm.vat_10
      this.entryForm.net_amount = total - this.entryForm.vat_amount
      
      // Calculate Yhteensä (VAT amount) for display
      this.entryForm.yhteensa = this.entryForm.vat_amount
    },
    calculateTotals() {
      const taxFree = parseFloat(this.entryForm.tax_free_amount) || 0
      const vatRate = parseFloat(this.entryForm.vat_percentage) || 0
      
      // Calculate VAT amounts based on tax-free amount and VAT rate
      if (vatRate === 25.5) {
        this.entryForm.vat_25_5 = Math.round((taxFree * 0.255) * 100) / 100
        this.entryForm.vat_14 = 0
        this.entryForm.vat_10 = 0
      } else if (vatRate === 14) {
        this.entryForm.vat_25_5 = 0
        this.entryForm.vat_14 = Math.round((taxFree * 0.14) * 100) / 100
        this.entryForm.vat_10 = 0
      } else if (vatRate === 10) {
        this.entryForm.vat_25_5 = 0
        this.entryForm.vat_14 = 0
        this.entryForm.vat_10 = Math.round((taxFree * 0.10) * 100) / 100
      } else {
        // Default 24% VAT
        this.entryForm.vat_25_5 = 0
        this.entryForm.vat_14 = 0
        this.entryForm.vat_10 = 0
      }
      
      const vat25_5 = parseFloat(this.entryForm.vat_25_5) || 0
      const vat14 = parseFloat(this.entryForm.vat_14) || 0
      const vat10 = parseFloat(this.entryForm.vat_10) || 0
      
      this.entryForm.total_amount = Math.round((taxFree + vat25_5 + vat14 + vat10) * 100) / 100
      this.entryForm.vat_amount = Math.round((vat25_5 + vat14 + vat10) * 100) / 100
      this.entryForm.net_amount = Math.round(taxFree * 100) / 100
    },
    async saveEntry() {
      try {
        if (this.isEditingEntry) {
          await api.put(`/accounting_entries.php?id=${this.entryForm.id}`, this.entryForm)
        } else {
          await api.post('/accounting_entries.php', this.entryForm)
        }
        
        this.closeEntryModal()
        this.fetchEntries()
      } catch (error) {
        console.error('Error saving entry:', error)
      }
    },
    async deleteEntry(id) {
      if (!confirm('Haluatko varmasti poistaa tämän tapahtuman?')) {
        return
      }
      
      try {
        await api.delete(`/accounting_entries.php?id=${id}`)
        this.fetchEntries()
      } catch (error) {
        console.error('Error deleting entry:', error)
      }
    },
    applyFilters() {
      this.currentPage = 1
    },
    exportToExcel() {
      // Implementation for Excel export
      alert('Excel-vienti ominaisuus tulossa pian!')
    }
  },
  mounted() {
    this.fetchEntries()
    this.fetchCategories()
  }
}
</script>

<style scoped>
.excel-accounting-section {
  padding: 20px;
}

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
}

.section-header h2 {
  margin: 0;
  color: white;
}

.header-actions {
  display: flex;
  gap: 10px;
}

.filters {
  display: flex;
  gap: 15px;
  margin-bottom: 20px;
  padding: 15px;
  background-color: #f8f9fa;
  border-radius: 8px;
}

.filter-group {
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.filter-group label {
  font-weight: 600;
  color: #495057;
}

.filter-group input,
.filter-group select {
  padding: 8px;
  border: 1px solid #ddd;
  border-radius: 4px;
  font-size: 14px;
}

.summary-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 20px;
  margin-bottom: 20px;
}

.summary-card {
  padding: 20px;
  border-radius: 8px;
  text-align: center;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.summary-card.income {
  background-color: #d4edda;
  border-left: 4px solid #28a745;
}

.summary-card.expenses {
  background-color: #f8d7da;
  border-left: 4px solid #dc3545;
}

.summary-card.balance {
  background-color: #e2e3e5;
  border-left: 4px solid #6c757d;
}

.summary-card.balance.positive {
  border-left-color: #28a745;
}

.summary-card.balance.negative {
  border-left-color: #dc3545;
}

.summary-card h3 {
  margin: 0 0 10px 0;
  color: #495057;
}

.summary-card .amount {
  font-size: 24px;
  font-weight: 700;
  margin: 0;
  color: #333;
}

.entries-section {
  background-color: white;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 20px;
}

.table th,
.table td {
  padding: 12px;
  text-align: left;
  border-bottom: 1px solid #dee2e6;
}

.table th {
  background-color: #f8f9fa;
  font-weight: 600;
  color: #495057;
}

.table tbody tr:hover {
  background-color: #f8f9fa;
}

.table tbody tr.income {
  background-color: rgba(40, 167, 69, 0.05);
  color: #333 !important;
}

.table tbody tr.expense {
  background-color: rgba(220, 53, 69, 0.05);
  color: #333 !important;
}

.currency {
  text-align: right;
  font-family: 'Courier New', monospace;
  font-weight: 600;
}

.percentage {
  text-align: center;
  font-weight: 600;
}

.entry-type-badge {
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 12px;
  font-weight: 600;
}

.entry-type-badge.tulo {
  background-color: #28a745;
  color: white;
}

.entry-type-badge.kulu {
  background-color: #dc3545;
  color: white;
}

.actions {
  display: flex;
  gap: 5px;
}

.btn {
  padding: 6px 12px;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  font-size: 12px;
  transition: background-color 0.2s ease;
}

.btn-sm {
  padding: 4px 8px;
  font-size: 11px;
}

.btn-primary {
  background-color: #007bff;
  color: white;
}

.btn-primary:hover {
  background-color: #0056b3;
}

.btn-secondary {
  background-color: #6c757d;
  color: white;
}

.btn-secondary:hover {
  background-color: #545b62;
}

.btn-success {
  background-color: #28a745;
  color: white;
}

.btn-success:hover {
  background-color: #1e7e34;
}

.btn-danger {
  background-color: #dc3545;
  color: white;
}

.btn-danger:hover {
  background-color: #c82333;
}

.modal {
  position: fixed;
  z-index: 1000;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0,0,0,0.5);
  display: flex;
  align-items: center;
  justify-content: center;
}

.modal-content {
  background-color: white;
  padding: 30px;
  border-radius: 8px;
  width: 90%;
  max-width: 600px;
  max-height: 90vh;
  overflow-y: auto;
  position: relative;
}

.close {
  position: absolute;
  right: 15px;
  top: 15px;
  font-size: 24px;
  cursor: pointer;
  color: #aaa;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 15px;
}

.form-group {
  margin-bottom: 15px;
}

.form-group label {
  display: block;
  margin-bottom: 5px;
  font-weight: 600;
  color: #495057;
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 10px;
  border: 1px solid #ddd;
  border-radius: 4px;
  font-size: 14px;
}

.form-group textarea {
  min-height: 80px;
  resize: vertical;
}

.form-actions {
  display: flex;
  gap: 10px;
  justify-content: flex-end;
  margin-top: 20px;
}

.loading {
  text-align: center;
  padding: 40px;
  color: #333;
}

.no-data {
  text-align: center;
  padding: 40px;
  color: #6c757d;
}

.pagination {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 15px;
  margin-top: 20px;
}

.page-info {
  color: #6c757d;
  font-weight: 600;
}
</style>
