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

export async function initChat() {
    if (!sessionId || !currentPersona) return;
    const res = await fetch('/chat/init', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ message: '', session_id: sessionId, persona_id: currentPersona }),
    });
    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);
}

export function createImagePromptBlock(promptText) {
    const block = document.createElement('div');
    block.className = 'image-prompt-block';

    const header = document.createElement('div');
    header.className = 'image-prompt-header';
    header.innerHTML = '<span>🎨 SD prompt</span>';

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

    const genBtn = document.createElement('button');
    genBtn.type = 'button';
    genBtn.className = 'gen-image-btn';
    genBtn.textContent = '🖼 Генерировать';
    genBtn.addEventListener('click', () => generateImageViaA1111(promptText, block));
    header.appendChild(genBtn);

    const textEl = document.createElement('span');
    textEl.className = 'prompt-text';
    textEl.textContent = promptText;

    block.appendChild(header);
    block.appendChild(textEl);
    return block;
}

function renderChoices(wrapper, choices) {
    if (!choices || !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', () => {
            dom.inputEl.value = c.label;
            dom.inputEl.focus();
        });
        row.appendChild(btn);
    }
    wrapper.appendChild(row);
}

function renderResolution(wrapper, resolution) {
    if (!resolution?.text) return;
    const block = document.createElement('div');
    block.className = 'resolution-block';
    block.innerHTML = `
        <div class="resolution-title">Resolution (d20=${resolution.roll}, ${resolution.outcome})</div>
        <div class="resolution-text"></div>
    `;
    block.querySelector('.resolution-text').textContent = resolution.text;
    wrapper.appendChild(block);
}

function renderDebugBlocks(wrapper, blocks) {
    if (!blocks || !blocks.length) return;
    for (const b of blocks) {
        if (!b?.text) continue;
        if (b.type === 'global_plot') {
            addMessage('assistant', `--- Global plot ---\n${b.text}\n---`);
        } else if (b.type === 'facts') {
            addMessage('assistant', b.text);
        } else if (b.type === 'status_quo') {
            addMessage('assistant', b.text);
        } else {
            addMessage('assistant', b.text);
        }
    }
}

async function generateImageViaA1111(promptText, block) {
    block.parentElement.querySelector('.chat-image')?.remove();
    block.parentElement.querySelector('.image-error')?.remove();

    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);

        const img = document.createElement('img');
        img.className = 'chat-image';
        img.src = data.image_path;
        block.parentElement.appendChild(img);
    } catch (e) {
        const err = document.createElement('div');
        err.className = 'image-error';
        err.textContent = '🖼 ' + e.message;
        block.parentElement.appendChild(err);
    }
}

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

export function addMessage(role, content = '', imagePrompt = null, imagePath = 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));
    if (imagePath) appendChatImage(wrapper, imagePath);

    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() {
    const text = dom.inputEl.value.trim();
    if (!text || !sessionId) return;

    dom.inputEl.value = '';
    dom.inputEl.style.height = 'auto';
    dom.sendBtn.disabled = true;

    addMessage('user', text);
    showTyping();

    try {
        const res = await fetch('/chat/stream', {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ message: text, session_id: sessionId, persona_id: currentPersona }),
        });
        if (!res.ok) throw new Error('Ошибка сервера: ' + res.status);

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

        removeTyping();

        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;
                try {
                    const data = JSON.parse(line.slice(6));

                    if (data.chunk !== undefined) {
                        if (!bubble) {
                            bubble = addMessage('assistant', '');
                            bubble.classList.add('typing-active');
                        }
                        bubble.textContent += data.chunk;
                        bubble.textContent = bubble.textContent.replace(/\[IMAGE_PROMPT:.*?\]/gs, '').trim();
                        dom.messagesEl.scrollTop = dom.messagesEl.scrollHeight;
                    }

                    if (data.done) {
                        bubble?.classList.remove('typing-active');
                        if (data.image_prompt && bubble) {
                            bubble.parentElement.appendChild(createImagePromptBlock(data.image_prompt));
                        }
                        if (data.image_path && bubble) {
                            appendChatImage(bubble.parentElement, data.image_path);
                        }
                        if (data.image_error && bubble) {
                            const err = document.createElement('div');
                            err.className = 'image-error';
                            err.textContent = '🖼 ' + data.image_error;
                            bubble.parentElement.appendChild(err);
                        }
                        if (data.choices && bubble) {
                            renderChoices(bubble.parentElement, data.choices);
                        }
                        if (data.resolution && bubble) {
                            // show resolution under the last user message (best-effort: attach near assistant response)
                            renderResolution(bubble.parentElement, data.resolution);
                        }
                        if (data.debug) {
                            renderDebugBlocks(bubble?.parentElement || dom.messagesEl, data.debug);
                        }
                        const { loadSessions } = await import('./sessions.js');
                        loadSessions();
                    }
                } catch { /* skip */ }
            }
        }
    } 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();
}