/* chapter write page: 大纲编辑 + 上下文面板 + SSE 流式生成 + 暂停/继续/重写. */

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

const NOVEL_ID = window.NOVEL_ID;
const CHAPTER_ID = window.CHAPTER_ID;

const alertsEl = document.getElementById("cwAlerts");
const outlineEl = document.getElementById("cwOutline");
const outputEl = document.getElementById("cwOutput");
const wordCountEl = document.getElementById("cwWordCount");
const ctxSummaryEl = document.getElementById("cwContextSummary");

const btn = {
    generate: document.getElementById("cwGenerate"),
    pause: document.getElementById("cwPause"),
    resume: document.getElementById("cwResume"),
    regen: document.getElementById("cwRegen"),
    edit: document.getElementById("cwEdit"),
    save: document.getElementById("cwSave"),
    approve: document.getElementById("cwApprove"),
    saveOutline: document.getElementById("cwSaveOutline"),
};

let stream = null;
let accumulated = "";   // 已生成文本 (暂停断点)
let editing = false;

/* ---------------- 状态管理 ---------------- */

function setStreaming(on) {
    btn.generate.disabled = on;
    btn.pause.disabled = !on;
    btn.regen.disabled = on || !accumulated;
    btn.resume.disabled = on || !accumulated;
    btn.saveOutline.disabled = on;
    if (on) {
        btn.edit.disabled = true;
        btn.save.disabled = true;
        btn.approve.disabled = true;
    }
}

function setIdleWithContent() {
    btn.generate.disabled = false;
    btn.pause.disabled = true;
    btn.resume.disabled = true;
    btn.regen.disabled = false;
    btn.edit.disabled = false;
    btn.save.disabled = false;
    btn.approve.disabled = false;
}

function renderOutput() {
    outputEl.innerHTML = accumulated
        ? escapeHtml(accumulated)
        : '<span class="text-muted">点击"生成"开始写作…</span>';
    outputEl.scrollTop = outputEl.scrollHeight;
    wordCountEl.textContent = accumulated ? "当前字数: " + accumulated.length : "";
}

/* ---------------- 加载章节 + 上下文 ---------------- */

async function loadChapter() {
    try {
        const ch = await fetchJson("/api/chapters/" + CHAPTER_ID);
        document.getElementById("cwTitle").textContent =
            "第" + (ch.volume || 1) + "卷 第" + (ch.chapter_number || 1) + "章 " + (ch.title || "");
        outlineEl.value = ch.outline || "";
        if (ch.content) {
            accumulated = ch.content;
            renderOutput();
            setIdleWithContent();
        }
    } catch (err) {
        showError(alertsEl, "加载章节失败: " + err.message);
    }
}

async function loadContext() {
    const el = document.getElementById("cwContext");
    try {
        const ctx = await fetchJson("/api/chapters/" + CHAPTER_ID + "/context");
        let html = "";

        html += "<details open><summary class=\"fw-bold\">前文摘要 ("
            + ctx.earlier_summaries.length + ")</summary>";
        html += ctx.earlier_summaries.length
            ? ctx.earlier_summaries.map((s) =>
                "<p class=\"small mb-1\">第" + s.volume + "卷 第" + s.chapter_number + "章 "
                + escapeHtml(s.title || "") + ": " + escapeHtml(s.summary) + "</p>").join("")
            : '<p class="small text-muted">无</p>';
        html += "</details>";

        html += "<details class=\"mt-2\"><summary class=\"fw-bold\">前章正文 ("
            + ctx.prev_chapters.length + ")</summary>";
        html += ctx.prev_chapters.length
            ? ctx.prev_chapters.map((c) =>
                "<details class=\"ms-2\"><summary class=\"small\">第" + c.volume + "卷 第"
                + c.chapter_number + "章 " + escapeHtml(c.title || "") + "</summary>"
                + "<pre class=\"small\" style=\"white-space:pre-wrap;max-height:200px;overflow-y:auto;\">"
                + escapeHtml(c.content) + "</pre></details>").join("")
            : '<p class="small text-muted">无 (这是第一章)</p>';
        html += "</details>";

        html += "<details class=\"mt-2\"><summary class=\"fw-bold\">相关角色 ("
            + ctx.characters.length + ")</summary>";
        html += ctx.characters.length
            ? ctx.characters.map((c) =>
                "<p class=\"small mb-1\"><strong>" + escapeHtml(c.name) + "</strong> ("
                + escapeHtml(c.role || "") + "): "
                + escapeHtml((c.description || "").slice(0, 200)) + "</p>").join("")
            : '<p class="small text-muted">无</p>';
        html += "</details>";

        html += "<details class=\"mt-2\"><summary class=\"fw-bold\">未回收伏笔 ("
            + ctx.open_foreshadowing.length + ")</summary>";
        html += ctx.open_foreshadowing.length
            ? ctx.open_foreshadowing.map((f) =>
                "<p class=\"small mb-1\">" + escapeHtml(f.description) + "</p>").join("")
            : '<p class="small text-muted">无</p>';
        html += "</details>";

        html += '<p class="small text-muted mt-2">上下文总大小: ' + ctx.total_chars + " 字符</p>";
        el.innerHTML = html;
    } catch (err) {
        el.innerHTML = '<div class="alert alert-danger small">' + escapeHtml(err.message) + "</div>";
    }
}

/* ---------------- 生成控制 ---------------- */

function startStream(prefix) {
    if (stream) stream.close();
    setStreaming(true);
    ctxSummaryEl.innerHTML = "";

    const params = new URLSearchParams({ csrf_token: document.querySelector('meta[name="csrf-token"]').content });
    if (prefix) params.append("prefix", prefix);

    stream = createSSEStream("/api/chapters/" + CHAPTER_ID + "/generate?" + params.toString(), {
        onContext: (summary) => {
            ctxSummaryEl.innerHTML = '<div class="alert alert-info small py-1">'
                + escapeHtml(summary) + "</div>";
        },
        onToken: (t) => {
            accumulated += t;
            renderOutput();
        },
        onDone: (content) => {
            accumulated = content;
            renderOutput();
            stream = null;
            setIdleWithContent();
        },
        onError: (msg) => {
            showError(alertsEl, "生成失败: " + msg);
            stream = null;
            setStreaming(false);
            btn.resume.disabled = !accumulated;
        },
    });
}

btn.generate.addEventListener("click", () => {
    accumulated = "";
    renderOutput();
    startStream(null);
});

btn.pause.addEventListener("click", () => {
    if (stream) { stream.close(); stream = null; }
    setStreaming(false);
    btn.resume.disabled = !accumulated;
    btn.regen.disabled = !accumulated;
});

btn.resume.addEventListener("click", () => startStream(accumulated));

btn.regen.addEventListener("click", () => {
    if (stream) { stream.close(); stream = null; }
    accumulated = "";
    renderOutput();
    startStream(null);
});

btn.edit.addEventListener("click", () => {
    editing = !editing;
    outputEl.contentEditable = editing ? "true" : "false";
    btn.edit.textContent = editing ? "完成编辑" : "编辑";
    if (editing) outputEl.focus();
    else accumulated = outputEl.innerText;
});

btn.save.addEventListener("click", async () => {
    if (editing) accumulated = outputEl.innerText;
    try {
        await postJson("/api/chapters/" + CHAPTER_ID, { content: accumulated });
        renderOutput();
        ctxSummaryEl.innerHTML = '<div class="alert alert-success small py-1">已保存</div>';
    } catch (err) {
        showError(alertsEl, "保存失败: " + err.message);
    }
});

btn.approve.addEventListener("click", async () => {
    if (editing) accumulated = outputEl.innerText;
    try {
        await postJson("/api/chapters/" + CHAPTER_ID, { content: accumulated, status: "done" });
        ctxSummaryEl.innerHTML = '<div class="alert alert-success small py-1">本章已通过 (status=done)</div>';
    } catch (err) {
        showError(alertsEl, "操作失败: " + err.message);
    }
});

btn.saveOutline.addEventListener("click", async () => {
    try {
        await postJson("/api/chapters/" + CHAPTER_ID, { outline: outlineEl.value });
        ctxSummaryEl.innerHTML = '<div class="alert alert-success small py-1">大纲已保存</div>';
        loadContext();
    } catch (err) {
        showError(alertsEl, "保存大纲失败: " + err.message);
    }
});

/* ---------------- init ---------------- */

loadChapter();
loadContext();