/**
 * history.js - プロンプト生成履歴の管理
 * 
 * 主な機能:
 * - 履歴の保存と読み込み
 * - 履歴の検索
 * - 履歴項目の編集と削除
 * - ストレージ使用量の表示
 * 
 * 重要な関数:
 * - saveToHistory(): 新しい履歴項目を保存
 * - updateHistoryList(): 履歴リストを更新
 * - filterHistory(): 履歴の検索機能
 * - loadHistoryItem(): 履歴項目を読み込み
 * 
 * 注意事項:
 * - 履歴の最大サイズは3MB
 * - 容量超過時は古い履歴から自動削除
 */

function saveToHistory(title) {
    if(!title) {
        title = document.getElementById('query').value.slice(0, 10);
    }
    const historyItem = {
        query: document.getElementById('query').value,
        promptEn: document.getElementById('promptEn').value,
        promptMyLanguage: document.getElementById('promptMyLanguage').value,
        danbooruTags: document.getElementById('danbooruTags').value,
        timestamp: new Date().toISOString(),
        title: title
    };

    let history = JSON.parse(localStorage.getItem('gemini_prompt_history') || '[]');
    history.unshift(historyItem);
    // 履歴の合計サイズが3MB以下になるまで古い項目を削除
    while (JSON.stringify(history).length > 3 * 1024 * 1024) {
        history.pop();
    }
    localStorage.setItem('gemini_prompt_history', JSON.stringify(history));

    updateHistoryList();
}
function updateHistoryList() {
    const historyList = document.getElementById('historyList');
    const noHistoryMessage = document.getElementById('noHistoryMessage');
    historyList.innerHTML = '';

    const history = JSON.parse(localStorage.getItem('gemini_prompt_history') || '[]');

    if (history.length === 0) {
        noHistoryMessage.classList.remove('d-none');
        historyList.classList.add('d-none');
    } else {
        noHistoryMessage.classList.add('d-none');
        historyList.classList.remove('d-none');

        // 容量プログレスバーを追加
        const storageUsage = JSON.stringify(history).length;
        const storageLimit = 3 * 1024 * 1024; // 3MB
        const usagePercentage = (storageUsage / storageLimit) * 100;

        const progressBarContainer = document.createElement('div');
        progressBarContainer.className = 'mb-3';
        progressBarContainer.innerHTML = `
            <div class="progress" style="height: 24px; border: 1px solid #dee2e6; position: relative;">
                <div class="progress-bar ${usagePercentage > 90 ? 'bg-danger' : 'bg-primary'}" role="progressbar" 
                     style="width: ${usagePercentage}%;" aria-valuenow="${usagePercentage}" aria-valuemin="0" aria-valuemax="100"></div>
                <div class="position-absolute w-100 h-100 d-flex align-items-center justify-content-center" style="top: 0; left: 0;">
                    <span style="color: white; text-shadow: -1px -1px 0 #000, 1px -1px 0 #000, -1px 1px 0 #000, 1px 1px 0 #000;">
                        ${(storageUsage / 1024 / 1024).toFixed(2)}MB / ${storageLimit / 1024 / 1024}MB
                    </span>
                </div>
            </div>
        `;
        historyList.appendChild(progressBarContainer);

        // 検索フォームを追加
        const searchForm = document.createElement('div');
        searchForm.className = 'mb-3';
        searchForm.innerHTML = `
            <input type="text" class="form-control" id="historySearchInput" placeholder="履歴を検索...">
        `;
        historyList.appendChild(searchForm);

        history.forEach((item, index) => {
            const li = document.createElement('li');
            li.className = 'list-group-item list-group-item-action d-flex justify-content-between align-items-start';
            li.dataset.item = JSON.stringify(item);

            const contentDiv = document.createElement('div');
            contentDiv.className = 'ms-2 me-auto';
            contentDiv.style.cursor = 'pointer';
            contentDiv.onclick = () => loadHistoryItem(index);

            const titleDiv = document.createElement('div');
            titleDiv.className = 'fw-bold text-truncate';
            titleDiv.textContent = item.title || item.query.slice(0, 10);

            const dateDiv = document.createElement('div');
            dateDiv.className = 'small text-muted';
            dateDiv.textContent = new Date(item.timestamp).toLocaleString();

            contentDiv.appendChild(titleDiv);
            contentDiv.appendChild(dateDiv);

            const buttonsContainer = document.createElement('div');
            buttonsContainer.className = 'd-flex';

            const editButton = document.createElement('button');
            editButton.className = 'btn btn-secondary btn-sm me-2';
            editButton.innerHTML = '<i class="fas fa-pencil-alt"></i>';
            editButton.onclick = (e) => {
                e.stopPropagation();
                editHistoryItemTitle(index, titleDiv);
            };

            const deleteButton = document.createElement('button');
            deleteButton.className = 'btn btn-danger btn-sm';
            deleteButton.innerHTML = '<i class="fas fa-trash"></i>';
            deleteButton.onclick = (e) => {
                e.stopPropagation();
                deleteHistoryItem(index);
            };

            buttonsContainer.appendChild(editButton);
            buttonsContainer.appendChild(deleteButton);

            li.appendChild(contentDiv);
            li.appendChild(buttonsContainer);
            historyList.appendChild(li);

            contentDiv.style.width = `calc(100% - ${buttonsContainer.offsetWidth}px)`;
        });

        // 検索機能を追加
        const searchInput = document.getElementById('historySearchInput');
        searchInput.addEventListener('input', filterHistory);
    }
}
function deleteHistoryItem(index) {
    if (confirm('Are you sure you want to delete this history item?')) {
        let history = JSON.parse(localStorage.getItem('gemini_prompt_history') || '[]');
        history.splice(index, 1);
        localStorage.setItem('gemini_prompt_history', JSON.stringify(history));
        updateHistoryList();
    }
}
function loadHistoryItem(index) {
    const history = JSON.parse(localStorage.getItem('gemini_prompt_history') || '[]');
    const item = history[index];

    document.getElementById('query').value = item.query;
    document.getElementById('promptEn').value = item.promptEn;
    document.getElementById('promptMyLanguage').value = item.promptMyLanguage;
    document.getElementById('danbooruTags').value = item.danbooruTags;

    saveToUserStorage(true);
}

function clearHistory() {
    if (confirm('Are you sure you want to delete all history items?')) {
        localStorage.removeItem('gemini_prompt_history');
        updateHistoryList();
    }
}

function createHistoryItem(item, index) {
    const li = document.createElement('li');
    li.className = 'list-group-item d-flex justify-content-between align-items-center';

    const titleSpan = document.createElement('span');
    titleSpan.textContent = item.title || item.query.slice(0, 10);
    titleSpan.className = 'me-2';
    li.appendChild(titleSpan);

    const buttonsContainer = document.createElement('div');

    const editButton = document.createElement('button');
    editButton.className = 'btn btn-sm btn-secondary me-2';
    editButton.innerHTML = '<i class="fas fa-pencil-alt"></i>';
    editButton.onclick = () => editHistoryItemTitle(index, titleSpan);

    const useButton = document.createElement('button');
    useButton.className = 'btn btn-sm btn-primary me-2';
    useButton.innerHTML = '<i class="fas fa-redo"></i>';
    useButton.onclick = () => useHistoryItem(index);

    const deleteButton = document.createElement('button');
    deleteButton.className = 'btn btn-sm btn-danger';
    deleteButton.innerHTML = '<i class="fas fa-trash"></i>';
    deleteButton.onclick = () => {
        if (confirm('Are you sure you want to delete this history item?')) {
            deleteHistoryItem(index);
        }
    };

    buttonsContainer.appendChild(editButton);
    buttonsContainer.appendChild(useButton);
    buttonsContainer.appendChild(deleteButton);
    li.appendChild(buttonsContainer);

    return li;
}

function editHistoryItemTitle(index, titleDiv) {
    const history = JSON.parse(localStorage.getItem('gemini_prompt_history') || '[]');
    const item = history[index];
    const currentTitle = item.title || item.query.slice(0, 10);

    const newTitle = prompt('New title:', currentTitle);
    if (newTitle !== null && newTitle.trim() !== '') {
        item.title = newTitle.trim();
        history[index] = item;
        localStorage.setItem('gemini_prompt_history', JSON.stringify(history));
        titleDiv.textContent = newTitle.trim();
    }
}

function filterHistory() {
    const searchInput = document.getElementById('historySearchInput');
    const searchTerm = searchInput.value.toLowerCase();
    const historyItems = document.querySelectorAll('#historyList li[data-item]');

    historyItems.forEach(item => {
        const itemData = JSON.parse(item.dataset.item);
        const searchableText = `${itemData.title} ${itemData.query} ${itemData.promptEn} ${itemData.promptMyLanguage} ${itemData.danbooruTags}`.toLowerCase();

        if (searchableText.includes(searchTerm)) {
            item.classList.remove('d-none');
        } else {
            item.classList.add('d-none');
        }
    });
}