/* deconstruct page: 拆书 UI - 顺序生成 5 个 section, 用户逐个确认后创建小说. */

import { escapeHtml, getCsrf, postJson, showError } from "../utils.js";
import { createSSEStream } from "../components/sse-client.js";

const SECTIONS = [
    { id: "concept", label: "主题构思" },
    { id: "world", label: "世界观" },
    { id: "characters", label: "角色" },
    { id: "outline", label: "大纲" },
    { id: "foreshadowing", label: "伏笔计划" },
];

// state: pending -> streaming -> confirm -> confirmed | skipped
const state = {};
SECTIONS.forEach((s) => { state[s.id] = { status: "pending", text: "" }; });

let activeStream = null;
let autoRunning = false;

const alertsEl = document.getElementById("dcAlerts");
const sectionsEl = document.getElementById("dcSections");
const startBtn = document.getElementById("dcStartBtn");
const createBtn = document.getElementById("dcCreateBtn");

/* ---------------- UI 构建 ---------------- */

const BADGE = {
    pending: '<span class="badge text-bg-secondary">待生成</span>',
    streaming: '<span class="badge text-bg-warning">生成中</span>',
    confirm: '<span class="badge text-bg-info">待确认</span>',
    confirmed: '<span class="badge text-bg-success">已确认</span>',
    skipped: '<span class="badge text-bg-dark">已跳过</span>',
};

function buildPanels() {
    sectionsEl.innerHTML = SECTIONS.map((s, i) => ''
        + '<div class="accordion-item" data-section="' + s.id + '">'
        + '  <h2 class="accordion-header">'
        + '    <button class="accordion-button' + (i === 0 ? "" : " collapsed") + '" type="button"'
        + '      data-bs-toggle="collapse" data-bs-target="#dcPanel-' + s.id + '">'
        + '      <span class="me-2">' + (i + 1) + '. ' + s.label + '</span>'
        + '      <span class="dc-badge">' + BADGE.pending + '</span>'
        + '    </button>'
        + '  </h2>'
        + '  <div id="dcPanel-' + s.id + '" class="accordion-collapse collapse' + (i === 0 ? " show" : "") + '">'
        + '    <div class="accordion-body">'
        + '      <textarea class="form-control dc-text" rows="8" placeholder="等待生成…"></textarea>'
        + '      <div class="mt-2 d-flex gap-2">'
        + '        <button type="button" class="btn btn-outline-success btn-sm dc-gen">生成</button>'
        + '        <button type="button" class="btn btn-outline-secondary btn-sm dc-skip">跳过 (用默认值)</button>'
        + '        <button type="button" class="btn btn-outline-primary btn-sm dc-confirm" disabled>确认</button>'
        + '      </div>'
        + '    </div>'
        + '  </div>'
        + '</div>').join("");

    sectionsEl.querySelectorAll(".accordion-item").forEach((item) => {
        const id = item.dataset.section;
        item.querySelector(".dc-gen").addEventListener("click", () => streamSection(id));
        item.querySelector(".dc-skip").addEventListener("click", () => skipSection(id));
        item.querySelector(".dc-confirm").addEventListener("click", () => confirmSection(id));
        item.querySelector(".dc-text").addEventListener("input", (e) => {
            state[id].text = e.target.value;
        });
    });
}

function setStatus(id, status) {
    state[id].status = status;
    const item = sectionsEl.querySelector('[data-section="' + id + '"]');
    item.querySelector(".dc-badge").innerHTML = BADGE[status];
    const genBtn = item.querySelector(".dc-gen");
    const confirmBtn = item.querySelector(".dc-confirm");
    genBtn.disabled = status === "streaming";
    genBtn.textContent = (status === "pending" || status === "streaming") ? "生成" : "重新生成";
    confirmBtn.disabled = status !== "confirm";
    updateCreateBtn();
}

function openPanel(id) {
    const panel = document.getElementById("dcPanel-" + id);
    if (panel && !panel.classList.contains("show")) {
        new bootstrap.Collapse(panel, { toggle: true });
    }
}

function updateCreateBtn() {
    createBtn.disabled = !SECTIONS.every(
        (s) => state[s.id].status === "confirmed" || state[s.id].status === "skipped"
    );
}

/* ---------------- 拆书流程 ---------------- */

function inputs(section) {
    const confirmed = {};
    SECTIONS.forEach((s) => {
        if (state[s.id].status === "confirmed" && s.id !== section) confirmed[s.id] = state[s.id].text;
    });
    return {
        title: document.getElementById("dcTitle").value.trim(),
        genre: document.getElementById("dcGenre").value,
        style: document.getElementById("dcStyle").value.trim(),
        target_words: document.getElementById("dcWords").value,
        reference_novel: document.getElementById("dcRef").value.trim(),
        section,
        confirmed: JSON.stringify(confirmed),
        csrf_token: getCsrf(),
    };
}

function streamSection(id) {
    const inp = inputs(id);
    if (!inp.title) {
        showError(alertsEl, "请先填写书名");
        return;
    }
    if (activeStream) activeStream.close();

    const item = sectionsEl.querySelector('[data-section="' + id + '"]');
    const textarea = item.querySelector(".dc-text");
    textarea.value = "";
    state[id].text = "";
    setStatus(id, "streaming");
    openPanel(id);

    const url = "/api/deconstruct/stream?" + new URLSearchParams(inp).toString();
    activeStream = createSSEStream(url, {
        onToken: (t) => {
            textarea.value += t;
            state[id].text = textarea.value;
            textarea.scrollTop = textarea.scrollHeight;
        },
        onSectionEnd: (section, content) => {
            textarea.value = content;
            state[section].text = content;
            setStatus(section, "confirm");
            activeStream = null;
            if (autoRunning) nextSection(section);
        },
        onError: (msg) => {
            showError(alertsEl, "生成失败: " + msg);
            setStatus(id, "pending");
            activeStream = null;
            autoRunning = false;
        },
    });
}

function nextSection(doneId) {
    const idx = SECTIONS.findIndex((s) => s.id === doneId);
    const next = SECTIONS.slice(idx + 1).find((s) => state[s.id].status === "pending");
    if (next) streamSection(next.id);
    else autoRunning = false;
}

function confirmSection(id) {
    const item = sectionsEl.querySelector('[data-section="' + id + '"]');
    state[id].text = item.querySelector(".dc-text").value;
    setStatus(id, "confirmed");
}

function skipSection(id) {
    if (activeStream) { activeStream.close(); activeStream = null; }
    if (!state[id].text) state[id].text = "(用户跳过, 由 AI 在写作时自由发挥)";
    setStatus(id, "skipped");
}

/* ---------------- 解析 + 创建小说 ---------------- */

function parseCharacters(text) {
    const out = [];
    text.split(/【角色】/).slice(1).forEach((chunk) => {
        const lines = chunk.trim().split("\n").filter((l) => l.trim());
        if (!lines.length) return;
        const first = lines[0].trim();
        const name = first.split(/[\s,，:：/]/)[0].trim() || "未命名";
        out.push({ name, role: "角色", description: chunk.trim() });
    });
    return out;
}

function parseOutline(text) {
    const chapters = [];
    let volume = 1;
    let seq = 0;
    text.split("\n").forEach((line) => {
        const t = line.trim();
        if (!t) return;
        const vm = t.match(/第\s*(\d+)\s*卷/);
        if (vm) { volume = parseInt(vm[1], 10); return; }
        const cm = t.match(/第\s*(\d+)\s*章[\s::：]*(.*)/);
        if (cm) {
            chapters.push({
                volume, chapter_number: parseInt(cm[1], 10),
                title: (cm[2] || "").split(/[—\-–]/)[0].trim(), outline: t,
            });
            seq = cm[1] ? parseInt(cm[1], 10) : seq;
            return;
        }
        seq += 1;
        chapters.push({ volume: 1, chapter_number: seq, title: "", outline: t });
    });
    return chapters;
}

function parseForeshadowing(text) {
    return text.split(/【伏笔】/).slice(1).map((chunk) => ({
        description: chunk.trim(),
    })).filter((f) => f.description);
}

async function createNovel() {
    const inp = inputs("concept");
    const characters = parseCharacters(state.characters.text);
    const outlineChapters = parseOutline(state.outline.text);
    const foreshadowing = parseForeshadowing(state.foreshadowing.text);
    if (state.characters.status === "confirmed" && !characters.length) {
        alert("角色文本未能解析出【角色】条目, 将只创建小说本体。");
    }
    createBtn.disabled = true;
    try {
        const resp = await postJson("/api/novels", {
            title: inp.title,
            genre: inp.genre,
            style: inp.style,
            target_words: parseInt(inp.target_words, 10),
            outline_chapters: outlineChapters,
            characters,
            foreshadowing,
        });
        window.location.href = "/novel/" + resp.id;
    } catch (err) {
        showError(alertsEl, "创建失败: " + err.message);
        createBtn.disabled = false;
    }
}

/* ---------------- 入口 ---------------- */

buildPanels();

startBtn.addEventListener("click", () => {
    autoRunning = true;
    const first = SECTIONS.find((s) => state[s.id].status === "pending") || SECTIONS[0];
    streamSection(first.id);
});

createBtn.addEventListener("click", createNovel);