document.addEventListener('DOMContentLoaded', () => {
    const numberInput = document.getElementById('numberInput');
    const fileInput = document.getElementById('fileInput');
    const dropzone = document.getElementById('dropzone');
    const splitMode = document.getElementById('splitMode');
    const splitValue = document.getElementById('splitValue');
    const splitBtn = document.getElementById('splitBtn');
    const autoDedupe = document.getElementById('autoDedupe');
    const resultsContainer = document.getElementById('resultsContainer');
    const totalCountEl = document.getElementById('totalCount');
    const uniqueCountEl = document.getElementById('uniqueCount');
    const dynamicCountsContainer = document.getElementById('dynamicCountsContainer');
    const dynamicInputsList = document.getElementById('dynamicInputsList');
    const unitText = document.getElementById('unitText');
    const batchCountBadge = document.getElementById('batchCountBadge');
    
    let allNumbers = [];

    // Helper: Extract numbers from text (Mobile number regex)
    const extractNumbers = (text) => {
        const matches = text.match(/1[3-9]\d{9}/g) || [];
        return matches;
    };

    // Update stats and allNumbers array
    const updateStats = () => {
        const text = numberInput.value;
        const extracted = extractNumbers(text);
        const unique = [...new Set(extracted)];
        
        totalCountEl.textContent = extracted.length.toLocaleString();
        uniqueCountEl.textContent = unique.length.toLocaleString();
        
        allNumbers = autoDedupe.checked ? unique : extracted;
    };

    numberInput.addEventListener('input', updateStats);
    autoDedupe.addEventListener('change', updateStats);

    // Dynamic UI for split modes
    const updateSplitUI = () => {
        const mode = splitMode.value;
        if (mode === 'count') {
            unitText.textContent = '份';
            dynamicCountsContainer.classList.remove('d-none');
            generateDynamicInputs();
        } else {
            unitText.textContent = '条';
            dynamicCountsContainer.classList.add('d-none');
        }
    };

    const generateDynamicInputs = () => {
        const numBatches = parseInt(splitValue.value);
        dynamicInputsList.innerHTML = '';
        
        if (isNaN(numBatches) || numBatches <= 1) {
            dynamicCountsContainer.classList.add('d-none');
            return;
        }

        dynamicCountsContainer.classList.remove('d-none');
        
        // Create N-1 inputs because the last one is always the remainder
        for (let i = 0; i < numBatches - 1; i++) {
            const div = document.createElement('div');
            div.className = 'input-group input-group-sm dynamic-batch-input';
            div.innerHTML = `
                <span class="input-group-text bg-white border-2">第 ${i + 1} 份数量</span>
                <input type="number" class="form-control border-2 batch-size-input" placeholder="留空则自动平均分配" min="1">
            `;
            dynamicInputsList.appendChild(div);
        }
    };

    splitMode.addEventListener('change', updateSplitUI);
    splitValue.addEventListener('input', generateDynamicInputs);

    // File handling
    dropzone.addEventListener('click', () => fileInput.click());
    fileInput.addEventListener('change', async (e) => {
        const file = e.target.files[0];
        if (!file) return;
        
        if (file.name.endsWith('.txt') || file.name.endsWith('.csv')) {
            const reader = new FileReader();
            reader.onload = (event) => {
                const content = event.target.result;
                numberInput.value += (numberInput.value ? '\n' : '') + content;
                updateStats();
                fileInput.value = '';
            };
            reader.readAsText(file);
        } else {
            // Placeholder for Excel/Word/PDF if needed, but for now just inform
            alert('当前支持直接读取 .txt 和 .csv 文件。Word/Excel/PDF 请直接复制其中的号码并粘贴到输入框。');
        }
    });

    // Splitting logic
    splitBtn.addEventListener('click', () => {
        updateStats(); // Ensure we have latest data
        if (allNumbers.length === 0) {
            alert('请先导入或粘贴号码！');
            return;
        }

        const mode = splitMode.value;
        const val = parseInt(splitValue.value);

        if (isNaN(val) || val <= 0) {
            alert('请输入有效的分批数值！');
            return;
        }

        let batches = [];
        let tempNumbers = [...allNumbers];

        if (mode === 'count') {
            const sizeInputs = document.querySelectorAll('.batch-size-input');
            let hasSpecificSizes = false;
            let specificSizes = [];
            
            sizeInputs.forEach(input => {
                const s = parseInt(input.value);
                if (!isNaN(s) && s > 0) {
                    hasSpecificSizes = true;
                    specificSizes.push(s);
                } else {
                    specificSizes.push(null);
                }
            });

            if (hasSpecificSizes) {
                // Specific size splitting
                for (let i = 0; i < val - 1; i++) {
                    const size = specificSizes[i];
                    if (size !== null && size > 0) {
                        batches.push(tempNumbers.splice(0, size));
                    } else {
                        // If one is empty but others are not, we need a strategy. 
                        // Let's treat empty as 0 for now or average the rest?
                        // User said "if no number, system default split". 
                        // But if some have numbers and others don't, it's ambiguous.
                        // We'll calculate the remaining needed batches.
                        const remainingCount = val - batches.length;
                        const avg = Math.ceil(tempNumbers.length / remainingCount);
                        batches.push(tempNumbers.splice(0, avg));
                    }
                }
                // Add the remainder to the last batch
                if (tempNumbers.length > 0) {
                    batches.push(tempNumbers);
                } else if (batches.length < val) {
                    // If no numbers left but we need more batches, add empty ones
                    while (batches.length < val) batches.push([]);
                }
            } else {
                // Average splitting
                const batchSize = Math.ceil(tempNumbers.length / val);
                for (let i = 0; i < val; i++) {
                    if (tempNumbers.length > 0) {
                        batches.push(tempNumbers.splice(0, batchSize));
                    } else {
                        batches.push([]);
                    }
                }
            }
        } else {
            // Split by fixed size per batch
            while (tempNumbers.length > 0) {
                batches.push(tempNumbers.splice(0, val));
            }
        }

        renderResults(batches);
    });

    const renderResults = (batches) => {
        resultsContainer.innerHTML = '';
        batchCountBadge.textContent = `${batches.length} 个批次`;
        batchCountBadge.classList.remove('d-none');
        
        batches.forEach((batch, index) => {
            const card = document.createElement('div');
            card.className = 'card batch-card animate-fadeIn';
            
            const previewText = batch.slice(0, 30).join(', ');
            const hasMore = batch.length > 30;

            card.innerHTML = `
                <div class="card-body p-4">
                    <div class="batch-header">
                        <div class="batch-title">
                            <span class="badge bg-primary">第 ${index + 1} 批</span>
                            <span class="badge-count">${batch.length.toLocaleString()} 条号码</span>
                        </div>
                        <button class="btn btn-primary btn-sm px-3 download-btn" data-index="${index}">
                            <i data-lucide="download" style="width: 14px;"></i> 下载 TXT
                        </button>
                    </div>
                    <div class="mb-3">
                        <div class="input-group input-group-sm">
                            <span class="input-group-text bg-light border-0"><i data-lucide="tag" style="width: 12px;"></i></span>
                            <input type="text" class="form-control border-0 bg-light remark-input" placeholder="输入备注（将作为文件名）...">
                        </div>
                    </div>
                    <details>
                        <summary class="small">查看部分预览</summary>
                        <div class="mt-2 p-3 bg-light rounded-3 small text-muted font-monospace" style="max-height: 120px; overflow-y: auto; border: 1px solid rgba(0,0,0,0.05);">
                            ${batch.length > 0 ? previewText + (hasMore ? ' ...' : '') : '<span class="fst-italic">此批次为空</span>'}
                        </div>
                    </details>
                </div>
            `;
            
            resultsContainer.appendChild(card);
            
            // Download handler
            card.querySelector('.download-btn').addEventListener('click', () => {
                if (batch.length === 0) {
                    alert('此批次没有号码可下载。');
                    return;
                }
                const remark = card.querySelector('.remark-input').value.trim() || `批次_${index + 1}_${batch.length}条`;
                const blob = new Blob([batch.join('\n')], { type: 'text/plain;charset=utf-8' });
                const url = URL.createObjectURL(blob);
                const a = document.createElement('a');
                a.href = url;
                a.download = `${remark}.txt`;
                document.body.appendChild(a);
                a.click();
                document.body.removeChild(a);
                URL.revokeObjectURL(url);
            });
        });

        if (window.lucide) {
            lucide.createIcons();
        }
        
        resultsContainer.scrollIntoView({ behavior: 'smooth', block: 'start' });
    });

    // Initial UI Setup
    updateSplitUI();
});