import { sessionId, currentPersona, dom } from './state.js';
import { parseImagePromptFromContent, copyToClipboard, splitSdPromptForCopy } from './utils.js';

export async function initChat(options = {}) {
    if (!sessionId) return;
    const payload = { message: '', session_id: sessionId };
    if (options.first_mes_override?.trim()) payload.first_mes_override = options.first_mes_override.trim();
    const res = await fetch('/chat/init', { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify(payload) });
    if (!res.ok) return;
    const data = await res.json();
    if (data.first_mes) addMessage('assistant', data.first_mes);
}

export function updateEmptyState() {
    const hasMessages = dom.messagesEl.querySelector('.message');
    dom.emptyState?.classList.toggle('hidden', !!hasMessages);
}

function createImagePromptBlockSingle(label, promptText) {
    const block = document.createElement('div');
    block.className = 'image-prompt-block';
    const header = document.createElement('div');
    header.className = 'image-prompt-header';
    header.innerHTML = `<span>🎨 ${label}</span>`;

    const copyBtn = document.createElement('button');
    copyBtn.type = 'button';
    copyBtn.className = 'copy-prompt-btn';
    copyBtn.textContent = 'Копировать';
    copyBtn.addEventListener('click', async (e) => {
        e.preventDefault();
        e.stopPropagation();
        const full = textEl.textContent?.trim() || promptText || '';
        const ok = await copyToClipboard(splitSdPromptForCopy(full));
        copyBtn.textContent = ok ? 'Скопировано' : 'Ошибка';
        setTimeout(() => { copyBtn.textContent = 'Копировать'; }, 1500);
    });
    header.appendChild(copyBtn);

    const regenBtn = document.createElement('button');
    regenBtn.type = 'button';
    regenBtn.className = 'copy-prompt-btn';
    regenBtn.textContent = '🖼 Перегенерировать';
    regenBtn.addEventListener('click', async () => {
        const wrapper = block.closest('.message');
        regenBtn.disabled = true;
        regenBtn.textContent = '⏳…';
        wrapper?.querySelectorAll('.chat-image-wrap, .chat-image, .image-error').forEach(el => el.remove());
        showImageGenerating(wrapper);
        try {
            const res = await fetch('/images/generate', {
                method: 'POST',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify({ session_id: sessionId, prompt: promptText }),
            });
            const data = await res.json();
            if (!res.ok) throw new Error(data.detail || res.statusText);
            removeImageGenerating(wrapper);
            appendChatImage(wrapper, data.image_path);
        } catch (e) {
            removeImageGenerating(wrapper);
            const err = document.createElement('div');
            err.className = 'image-error';
            err.textContent = '🖼 ' + e.message;
            wrapper?.appendChild(err);
        } finally {
            regenBtn.disabled = false;
            regenBtn.textContent = '🖼 Перегенерировать';
        }
    });
    header.appendChild(regenBtn);

    const textEl = document.createElement('span');
    textEl.className = 'prompt-text';
    textEl.textContent = promptText;
    block.appendChild(header);
    block.appendChild(textEl);
    return block;
}

export function createImagePromptBlock(promptText, promptAlt = null) {
    const wrap = document.createElement('div');
    wrap.className = 'image-prompt-blocks';
    wrap.appendChild(createImagePromptBlockSingle('SD prompt', promptText));
    const alt = (promptAlt || '').trim();
    const main = (promptText || '').trim();
    if (alt && alt !== main) {
        wrap.appendChild(createImagePromptBlockSingle('SD prompt (только теги)', promptAlt));
    }
    return wrap;
}

/** Replace or create tag + optional hybrid prompt blocks under a message. */
export function ensureImagePromptBlocks(wrapper, tagPrompt, altPrompt = null) {
    if (!wrapper || !tagPrompt) return;
    wrapper.querySelector('.image-prompt-blocks')?.remove();
    wrapper.querySelectorAll('.image-prompt-block').forEach(el => el.remove());
    wrapper.appendChild(createImagePromptBlock(tagPrompt, altPrompt || null));
}

const OUTCOME_CLASS = {
    'critical failure': 'outcome-crit-fail',
    'failure': 'outcome-fail',
    'success': 'outcome-success',
    'critical success': 'outcome-crit-success',
};

function buildNarratorEl(narrator) {
    const wrapper = document.createElement('div');
    wrapper.className = 'message narrator';
    const label = document.createElement('div');
    label.className = 'label';
    label.textContent = '📖 Рассказчик';
    wrapper.appendChild(label);
    const bubble = document.createElement('div');
    bubble.className = 'bubble';
    if (narrator.roll != null) {
        const diceBlock = document.createElement('div');
        diceBlock.className = `dice-block ${OUTCOME_CLASS[narrator.outcome] || ''}`;
        diceBlock.innerHTML = `<span class="dice-icon">🎲</span><span class="dice-roll">${narrator.roll}</span><span class="dice-outcome">${narrator.outcome}</span>`;
        bubble.appendChild(diceBlock);
    }
    const textEl = document.createElement('div');
    textEl.className = 'narrator-text';
    textEl.textContent = narrator.text;
    bubble.appendChild(textEl);
    wrapper.appendChild(bubble);
    return wrapper;
}

function renderNarratorMessage(narrator) {
    const el = buildNarratorEl(narrator);
    dom.messagesEl.appendChild(el);
    dom.messagesEl.scrollTop = dom.messagesEl.scrollHeight;
    return el;
}

export function renderChoices(wrapper, choices) {
    if (!choices?.length) return;
    const row = document.createElement('div');
    row.className = 'choice-row';
    for (const c of choices) {
        const btn = document.createElement('button');
        btn.type = 'button';
        btn.className = 'choice-btn';
        btn.textContent = c.label;
        btn.addEventListener('click', () => sendMessage(c.label, true));
        row.appendChild(btn);
    }
    wrapper.appendChild(row);
}

function renderDebugBlocks(wrapper, blocks) {
    if (!blocks?.length) return;
    for (const b of blocks) {
        if (!b?.text) continue;
        if (b.type === 'narrator_injection') {
            const w = document.createElement('div');
            w.className = 'message narrator';
            const lbl = document.createElement('div');
            lbl.className = 'label';
            lbl.textContent = '📖 Рассказчик';
            const bub = document.createElement('div');
            bub.className = 'bubble';
            bub.textContent = b.text;
            w.appendChild(lbl);
            w.appendChild(bub);
            dom.messagesEl.appendChild(w);
        }
    }
}

export function updateQuestPanel(quests) {
    const list = document.getElementById('questList');
    if (!list) return;
    list.innerHTML = '';
    for (const q of quests) {
        const el = document.createElement('div');
        el.className = `quest-item quest-${q.status}`;
        el.textContent = (q.status === 'done' ? '✅ ' : q.status === 'failed' ? '❌ ' : '🔸 ') + q.title;
        list.appendChild(el);
    }
}

export function updateAffinityDisplay(affinity) {
    const el = dom.affinityDisplay;
    if (!el) return;
    el.classList.remove('hidden');
    const hearts = affinity >= 10 ? '❤️❤️❤️' : affinity >= 5 ? '❤️❤️' : affinity >= 1 ? '❤️' : affinity <= -5 ? '💔' : '🤍';
    el.textContent = `${hearts} ${affinity > 0 ? '+' : ''}${affinity}`;
    el.className = `affinity-display ${affinity > 5 ? 'affinity-high' : affinity < -3 ? 'affinity-low' : ''}`;
}

export function appendChatImage(wrapper, imagePath, label = '') {
    if (!imagePath) return;
    const figure = document.createElement('figure');
    figure.className = 'chat-image-wrap';
    if (label) {
        const cap = document.createElement('figcaption');
        cap.className = 'chat-image-label';
        cap.textContent = label;
        figure.appendChild(cap);
    }
    const img = document.createElement('img');
    img.className = 'chat-image';
    img.src = imagePath;
    figure.appendChild(img);
    wrapper.appendChild(figure);
}

export function showImageGenerating(wrapper) {
    if (!wrapper || wrapper.querySelector('.image-generating')) return;
    const el = document.createElement('div');
    el.className = 'image-generating';
    el.setAttribute('role', 'status');
    el.innerHTML = '<span class="image-generating-spinner" aria-hidden="true"></span><span class="image-generating-text">Генерация изображения в ComfyUI…</span>';
    wrapper.appendChild(el);
    dom.messagesEl.scrollTop = dom.messagesEl.scrollHeight;
}

export function removeImageGenerating(wrapper) {
    wrapper?.querySelector('.image-generating')?.remove();
}

function attachMessageActions(wrapper, messageId, role) {
    if (!messageId) return;
    wrapper.dataset.messageId = String(messageId);
    const actions = document.createElement('div');
    actions.className = 'message-actions';
    const editBtn = document.createElement('button');
    editBtn.type = 'button';
    editBtn.textContent = '✏️';
    editBtn.title = 'Редактировать';
    editBtn.addEventListener('click', () => startEditMessage(wrapper, messageId));
    actions.appendChild(editBtn);
    if (role === 'assistant') {
        const regenBtn = document.createElement('button');
        regenBtn.type = 'button';
        regenBtn.textContent = '🔄';
        regenBtn.title = 'Перегенерировать';
        regenBtn.addEventListener('click', () => regenerateMessage(messageId, wrapper));
        actions.appendChild(regenBtn);
    }
    const branchBtn = document.createElement('button');
    branchBtn.type = 'button';
    branchBtn.textContent = '🌿';
    branchBtn.title = 'Ветка отсюда';
    branchBtn.addEventListener('click', () => forkFromMessage(messageId));
    actions.appendChild(branchBtn);
    wrapper.appendChild(actions);
}

async function startEditMessage(wrapper, messageId) {
    const bubble = wrapper.querySelector('.bubble');
    if (!bubble || wrapper.querySelector('.bubble-edit')) return;
    const original = bubble.textContent;
    const ta = document.createElement('textarea');
    ta.className = 'bubble-edit';
    ta.value = original;
    bubble.replaceWith(ta);
    wrapper.querySelector('.message-actions')?.remove();
    const saveRow = document.createElement('div');
    saveRow.className = 'message-actions';
    const saveBtn = document.createElement('button');
    saveBtn.textContent = 'Сохранить';
    const cancelBtn = document.createElement('button');
    cancelBtn.textContent = 'Отмена';
    saveRow.appendChild(saveBtn);
    saveRow.appendChild(cancelBtn);
    wrapper.appendChild(saveRow);
    cancelBtn.addEventListener('click', () => reloadChatFromServer(sessionId));
    saveBtn.addEventListener('click', async () => {
        const role = wrapper.classList.contains('user') ? 'user' : 'assistant';
        const doTruncate = confirm(role === 'user' ? 'Удалить все сообщения после этого? (рекомендуется)' : 'Удалить все сообщения после этого?');
        const res = await fetch(`/chat/messages/${messageId}`, {
            method: 'PATCH',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ content: ta.value.trim(), truncate_after: doTruncate }),
        });
        if (!res.ok) { alert('Ошибка сохранения'); return; }
        await reloadChatFromServer(sessionId);
        const { loadSessions } = await import('./sessions.js');
        loadSessions();
    });
}

async function regenerateMessage(messageId, wrapper) {
    if (!sessionId) return;
    wrapper?.remove();
    showTyping();
    dom.sendBtn.disabled = true;
    try {
        const res = await fetch('/chat/regenerate', {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ session_id: sessionId, message_id: messageId }),
        });
        if (!res.ok) throw new Error('Ошибка: ' + res.status);
        removeTyping();
        await consumeStream(res);
    } catch (err) {
        removeTyping();
        addMessage('assistant', '⚠️ ' + err.message);
    } finally {
        dom.sendBtn.disabled = false;
    }
}

async function forkFromMessage(messageId) {
    if (!sessionId) return;
    const res = await fetch(`/sessions/${sessionId}/fork`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ until_message_id: messageId }),
    });
    const data = await res.json();
    if (!res.ok) { alert(data.detail || 'Ошибка'); return; }
    const { switchSession, loadSessions } = await import('./sessions.js');
    await switchSession(data.session_id);
    await loadSessions();
}

export async function reloadChatFromServer(id) {
    const sid = id || sessionId;
    if (!sid) return;
    const histRes = await fetch(`/chat/history/${sid}`);
    if (!histRes.ok) return;
    const messages = await histRes.json();
    clearMessages();
    messages.filter(m => m.role !== 'system').forEach(m => {
        addMessage(
            m.role === 'user' ? 'user' : 'assistant',
            m.content,
            m.image_prompt,
            m.image_path ? `/static/${m.image_path}` : null,
            m.id,
            m.image_prompt_alt,
            m.image_path_alt ? `/static/${m.image_path_alt}` : null,
        );
    });
}

const IMAGE_PROMPT_RE = /\[IMAGE_PROMPT:.*?\]/gs;

async function consumeStream(res) {
    const reader = res.body.getReader();
    const decoder = new TextDecoder();
    let buffer = '';
    let bubble = null;

    while (true) {
        const { done, value } = await reader.read();
        if (done) break;
        buffer += decoder.decode(value, { stream: true });
        const lines = buffer.split('\n');
        buffer = lines.pop();

        for (const line of lines) {
            if (!line.startsWith('data: ')) continue;
            let data;
            try { data = JSON.parse(line.slice(6)); } catch { continue; }

            // Narrator arrives BEFORE chunks — render immediately
            if (data.narrator) {
                renderNarratorMessage(data.narrator);
            }

            if (data.chunk !== undefined) {
                if (!bubble) {
                    bubble = addMessage('assistant', '');
                    bubble.classList.add('typing-active');
                }
                bubble.textContent += data.chunk;
                dom.messagesEl.scrollTop = dom.messagesEl.scrollHeight;
            }

            if (data.image_generating && bubble) {
                bubble.classList.remove('typing-active');
                const wrapper = bubble.parentElement;
                if (data.image_prompt) {
                    ensureImagePromptBlocks(
                        wrapper,
                        data.image_prompt,
                        data.image_prompt_alt || null,
                    );
                }
                showImageGenerating(wrapper);
                dom.messagesEl.scrollTop = dom.messagesEl.scrollHeight;
            }

            if (data.done) {
                const wrapper = bubble?.parentElement;
                removeImageGenerating(wrapper);
                bubble?.classList.remove('typing-active');

                // Strip IMAGE_PROMPT tag from final text
                if (bubble) {
                    bubble.textContent = bubble.textContent.replace(IMAGE_PROMPT_RE, '').trim();
                }

                if (data.image_prompt && wrapper) {
                    ensureImagePromptBlocks(
                        wrapper,
                        data.image_prompt,
                        data.image_prompt_alt || null,
                    );
                }
                if (data.image_path && wrapper) {
                    appendChatImage(wrapper, data.image_path, '');
                }
                if (data.image_error && wrapper) {
                    const err = document.createElement('div');
                    err.className = 'image-error';
                    err.textContent = '🖼 ' + data.image_error;
                    wrapper.appendChild(err);
                }
                if (data.choices?.length && bubble) renderChoices(bubble.parentElement, data.choices);
                if (data.debug) renderDebugBlocks(bubble?.parentElement || dom.messagesEl, data.debug);
                if (data.affinity !== undefined) updateAffinityDisplay(data.affinity);
                if (data.quests?.length) updateQuestPanel(data.quests);

                const { loadSessions } = await import('./sessions.js');
                loadSessions();
            }
        }
    }
}

export function addMessage(
    role,
    content = '',
    imagePrompt = null,
    imagePath = null,
    messageId = null,
    imagePromptAlt = null,
    imagePathAlt = null,
) {
    updateEmptyState();
    const wrapper = document.createElement('div');
    wrapper.className = `message ${role}`;
    const label = document.createElement('div');
    label.className = 'label';
    label.textContent = role === 'user' ? 'Вы' : 'AI';
    wrapper.appendChild(label);

    let displayContent = content;
    let prompt = imagePrompt;
    if (role === 'assistant' && !prompt) {
        const parsed = parseImagePromptFromContent(content);
        displayContent = parsed.text;
        prompt = parsed.prompt;
    }

    const bubble = document.createElement('div');
    bubble.className = 'bubble';
    bubble.textContent = displayContent;
    wrapper.appendChild(bubble);

    if (role === 'assistant') {
        const translateBtn = document.createElement('button');
        translateBtn.type = 'button';
        translateBtn.className = 'translate-btn';
        translateBtn.textContent = '🌐 RU';
        let originalText = null;
        translateBtn.addEventListener('click', async () => {
            if (originalText !== null) {
                bubble.textContent = originalText;
                originalText = null;
                translateBtn.textContent = '🌐 RU';
                return;
            }
            originalText = bubble.textContent;
            translateBtn.disabled = true;
            translateBtn.textContent = '…';
            try {
                const res = await fetch('/translate/', {
                    method: 'POST',
                    headers: { 'Content-Type': 'application/json' },
                    body: JSON.stringify({ text: originalText }),
                });
                if (!res.ok) throw new Error(res.statusText);
                const data = await res.json();
                bubble.textContent = data.translated;
                translateBtn.textContent = '↩ Оригинал';
            } catch {
                originalText = null;
                translateBtn.textContent = '⚠️';
                setTimeout(() => { translateBtn.textContent = '🌐 RU'; }, 2000);
            }
            translateBtn.disabled = false;
        });
        wrapper.appendChild(translateBtn);
    }

    if (prompt) wrapper.appendChild(createImagePromptBlock(prompt, imagePromptAlt));
    if (imagePath) appendChatImage(wrapper, imagePath, imagePathAlt ? 'Теги' : '');
    if (imagePathAlt) appendChatImage(wrapper, imagePathAlt, 'Гибрид');
    attachMessageActions(wrapper, messageId, role);
    dom.messagesEl.appendChild(wrapper);
    dom.messagesEl.scrollTop = dom.messagesEl.scrollHeight;
    return bubble;
}

export function showTyping() {
    const typing = document.createElement('div');
    typing.className = 'typing';
    typing.id = 'typing';
    typing.innerHTML = '<span></span><span></span><span></span>';
    dom.messagesEl.appendChild(typing);
    dom.messagesEl.scrollTop = dom.messagesEl.scrollHeight;
}

export function removeTyping() {
    document.getElementById('typing')?.remove();
}

export function clearMessages() {
    dom.messagesEl.innerHTML = '';
    if (dom.emptyState) {
        dom.messagesEl.appendChild(dom.emptyState);
        dom.emptyState.classList.remove('hidden');
    }
}

export async function sendMessage(text, isNarratorChoice = false) {
    if (typeof text !== 'string') text = dom.inputEl.value.trim();
    if (!text || !sessionId) return;
    dom.inputEl.value = '';
    dom.inputEl.style.height = 'auto';
    dom.sendBtn.disabled = true;
    addMessage('user', isNarratorChoice ? `[${text}]` : text);
    showTyping();
    try {
        const res = await fetch('/chat/stream', {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ message: text, session_id: sessionId, is_narrator_choice: isNarratorChoice }),
        });
        if (!res.ok) throw new Error('Ошибка сервера: ' + res.status);
        removeTyping();
        await consumeStream(res);
    } catch (err) {
        removeTyping();
        addMessage('assistant', '⚠️ Ошибка: ' + err.message);
    } finally {
        dom.sendBtn.disabled = false;
        dom.inputEl.focus();
    }
}

export async function clearHistory() {
    if (!sessionId) return;
    await fetch(`/chat/${sessionId}`, { method: 'DELETE' });
    clearMessages();
}