const state = {
    catalog: [],
    system: [],
    plugins: [],
    issues: [],
    credentials: [],
    pluginsRoot: "",
    nodes: [],
    edges: [],
    selected: null,
    pending: null,
};

const canvas = document.getElementById("canvas");
const wires = document.getElementById("wires");
const inspector = document.getElementById("inspector");
const logEl = document.getElementById("log");

function uid(prefix) {
    return prefix + Math.random().toString(36).slice(2, 8);
}

function typeInfo(type) {
    return state.catalog.find((item) => item.type === type)
        || state.system.find((item) => item.type === type)
        || state.plugins.find((item) => item.type === type);
}

function pickNode(list, inputName) {
    return (list || []).find((item) => item.inputs?.some((p) => p.name === inputName));
}

function exampleGraph() {
    const fileInfo = pickNode(state.system, "filePath") || pickNode(state.catalog, "filePath");
    const weatherInfo = pickNode(state.plugins, "cities") || pickNode(state.system, "cities") || pickNode(state.catalog, "cities");
    if (!fileInfo || !weatherInfo) {
        logEl.textContent = "示例图需要目录里有「filePath 输入」和「cities 输入」的节点，请先刷新节点。";
        return { nodes: [], edges: [] };
    }
    const fileConfig = { credentialId: "llm-default" };
    if (fileInfo.inputs?.some((p) => p.name === "filePath")) {
        fileConfig.filePath = "Data/cities.txt";
    }
    return {
        nodes: [
            { id: "n1", type: fileInfo.type, title: fileInfo.name, x: 60, y: 80, config: fileConfig },
            { id: "n2", type: weatherInfo.type, title: weatherInfo.name, x: 420, y: 80, config: { credentialId: "llm-default" } },
        ],
        edges: [
            { id: "e1", from: "n1", to: "n2", fromPort: "cities", toPort: "cities", when: "hasValidCities" },
        ],
    };
}

function renderGroup(title, items) {
    if (!items.length) {
        return `<div class="palette-group">${title}</div><p class="hint">无</p>`;
    }
    return `<div class="palette-group">${title}</div>` + items.map((item) => `
    <div class="palette-item" data-type="${item.type}">
      <strong>${item.name}</strong><span class="tag">${item.origin === "plugin" ? "插件" : "系统"}</span>
      <div class="hint">${item.description}</div>
    </div>`).join("");
}

function renderPalette() {
    const issues = (state.issues || []).map((item) => `<div class="issue">[${item.level}] ${item.source}: ${item.message}</div>`).join("");
    document.getElementById("palette").innerHTML =
        `<p class="hint">${state.pluginsRoot || ""}</p>` +
        renderGroup("系统节点", state.system) +
        renderGroup("插件节点", state.plugins) +
        (issues ? `<div class="palette-group">扫描说明</div>${issues}` : "");
    document.querySelectorAll(".palette-item").forEach((el) => {
        el.onclick = () => addNode(el.dataset.type);
    });
}

function addNode(type) {
    const info = typeInfo(type);
    if (!info) {
        logEl.textContent = `没有类型 ${type}，请先刷新节点。`;
        return;
    }
    const config = { credentialId: "llm-default" };
    if (info.inputs?.some((p) => p.name === "filePath")) {
        config.filePath = "Data/cities.txt";
    }
    state.nodes.push({
        id: uid("n"),
        type,
        title: info.name,
        x: 80 + state.nodes.length * 40,
        y: 70 + state.nodes.length * 30,
        config,
    });
    render();
}

function render() {
    canvas.innerHTML = "";
    for (const node of state.nodes) {
        const info = typeInfo(node.type);
        if (!info) {
            continue;
        }
        const el = document.createElement("div");
        el.className = `node ${node.type} ${info.origin}` + (state.selected?.kind === "node" && state.selected.id === node.id ? " selected" : "");
        el.style.left = node.x + "px";
        el.style.top = node.y + "px";
        el.innerHTML = `
      <div class="node-head">${node.title}</div>
      <div class="ports">
        <div class="port-col">
          ${info.inputs.map((p) => `<div class="port in"><i class="dot" data-node="${node.id}" data-port="${p.name}" data-dir="in"></i>${p.name}</div>`).join("")}
        </div>
        <div class="port-col">
          ${info.outputs.map((p) => `<div class="port out">${p.name}<i class="dot" data-node="${node.id}" data-port="${p.name}" data-dir="out"></i></div>`).join("")}
        </div>
      </div>`;
        el.querySelector(".node-head").onmousedown = (e) => startDrag(e, node);
        el.onclick = (e) => {
            if (e.target.classList.contains("dot")) return;
            state.selected = { kind: "node", id: node.id };
            render();
        };
        canvas.appendChild(el);
    }
    canvas.querySelectorAll(".dot").forEach((dot) => {
        dot.onclick = (e) => {
            e.stopPropagation();
            onPort(dot.dataset.node, dot.dataset.port, dot.dataset.dir);
        };
    });
    drawWires();
    renderInspector();
}

function startDrag(e, node) {
    e.preventDefault();
    const wrap = document.querySelector(".canvas-wrap").getBoundingClientRect();
    const ox = e.clientX - wrap.left - node.x;
    const oy = e.clientY - wrap.top - node.y;
    const el = e.currentTarget.parentElement;
    const move = (ev) => {
        node.x = Math.max(0, ev.clientX - wrap.left - ox);
        node.y = Math.max(0, ev.clientY - wrap.top - oy);
        if (el) {
            el.style.left = node.x + "px";
            el.style.top = node.y + "px";
        }
        drawWires();
    };
    const up = () => {
        window.removeEventListener("mousemove", move);
        window.removeEventListener("mouseup", up);
    };
    window.addEventListener("mousemove", move);
    window.addEventListener("mouseup", up);
}

function onPort(nodeId, port, dir) {
    if (dir === "out") {
        state.pending = { nodeId, port };
        logEl.textContent = `已选输出 ${nodeTitle(nodeId)}.${port}，请点击下一个节点的输入端口。`;
        return;
    }
    if (!state.pending) {
        logEl.textContent = "请先点击上一节点的输出端口，再点本节点输入。";
        return;
    }
    if (state.pending.nodeId === nodeId) return;
    state.edges.push({
        id: uid("e"),
        from: state.pending.nodeId,
        to: nodeId,
        fromPort: state.pending.port,
        toPort: port,
        when: state.pending.port === "cities" || port === "cities" ? "hasValidCities" : "",
    });
    state.pending = null;
    state.selected = { kind: "edge", id: state.edges.at(-1).id };
    render();
}

function nodeTitle(id) {
    return state.nodes.find((n) => n.id === id)?.title ?? id;
}

function drawWires() {
    const wrap = document.querySelector(".canvas-wrap").getBoundingClientRect();
    wires.innerHTML = "";
    for (const edge of state.edges) {
        const from = document.querySelector(`.dot[data-node="${edge.from}"][data-port="${edge.fromPort}"][data-dir="out"]`);
        const to = document.querySelector(`.dot[data-node="${edge.to}"][data-port="${edge.toPort}"][data-dir="in"]`);
        if (!from || !to) continue;
        const a = from.getBoundingClientRect();
        const b = to.getBoundingClientRect();
        const x1 = a.left + a.width / 2 - wrap.left;
        const y1 = a.top + a.height / 2 - wrap.top;
        const x2 = b.left + b.width / 2 - wrap.left;
        const y2 = b.top + b.height / 2 - wrap.top;
        const path = document.createElementNS("http://www.w3.org/2000/svg", "path");
        path.setAttribute("d", `M ${x1} ${y1} C ${x1 + 80} ${y1}, ${x2 - 80} ${y2}, ${x2} ${y2}`);
        path.setAttribute("class", "wire" + (state.selected?.kind === "edge" && state.selected.id === edge.id ? " selected" : ""));
        path.style.pointerEvents = "stroke";
        path.onclick = () => {
            state.selected = { kind: "edge", id: edge.id };
            render();
        };
        wires.appendChild(path);
    }
}

function renderInspector() {
    if (!state.selected) {
        inspector.innerHTML = `<p class="hint">选中节点可填固定输入；选中连线可改「上一节点输出 → 下一节点输入」和运行条件。</p>`;
        return;
    }
    if (state.selected.kind === "node") {
        const node = state.nodes.find((n) => n.id === state.selected.id);
        const info = typeInfo(node.type);
        inspector.innerHTML = `
      <div><strong>${info.name}</strong> <span class="tag">${info.origin === "plugin" ? "插件" : "系统"}</span></div>
      <p class="hint">${info.description}</p>
      <label>显示名</label>
      <input id="title" value="${node.title}" />
      <label>LLM 凭据</label>
      <select id="credentialId">${(state.credentials || []).map((c) => `<option value="${c.id}" ${ (node.config.credentialId || "llm-default") === c.id ? "selected" : ""}>${c.name}（${c.hasApiKey ? "已配置 Key" : "缺少 Key"}）</option>`).join("")}</select>
      <p class="hint">endpoint / API Key 由宿主注入进程，不会出现在输入端口或导出的流程图里。</p>
      ${info.inputs.map((p) => `
        <label>固定输入 ${p.name}（${p.type}）${p.required ? " *" : ""}</label>
        <input data-config="${p.name}" value="${node.config[p.name] ?? ""}" placeholder="${p.description}" />
      `).join("")}
      <p class="hint">若该输入已从上一节点连线，运行时以连线为准。</p>
      <button type="button" id="delNode">删除节点</button>`;
        inspector.querySelector("#title").oninput = (e) => { node.title = e.target.value; };
        inspector.querySelector("#credentialId")?.addEventListener("change", (e) => { node.config.credentialId = e.target.value; });
        inspector.querySelectorAll("[data-config]").forEach((input) => {
            input.oninput = () => { node.config[input.dataset.config] = input.value; };
        });
        inspector.querySelector("#delNode").onclick = () => {
            state.edges = state.edges.filter((e) => e.from !== node.id && e.to !== node.id);
            state.nodes = state.nodes.filter((n) => n.id !== node.id);
            state.selected = null;
            render();
        };
        return;
    }
    const edge = state.edges.find((e) => e.id === state.selected.id);
    const from = state.nodes.find((n) => n.id === edge.from);
    const to = state.nodes.find((n) => n.id === edge.to);
    const fromInfo = typeInfo(from.type);
    const toInfo = typeInfo(to.type);
    inspector.innerHTML = `
    <div><strong>连线映射</strong></div>
    <p class="hint">上一节点输出 → 下一节点输入</p>
    <label>来自</label>
    <div>${from.title}</div>
    <label>输出端口</label>
    <select id="fromPort">${fromInfo.outputs.map((p) => `<option ${p.name === edge.fromPort ? "selected" : ""}>${p.name}</option>`).join("")}</select>
    <label>到达</label>
    <div>${to.title}</div>
    <label>输入端口</label>
    <select id="toPort">${toInfo.inputs.map((p) => `<option ${p.name === edge.toPort ? "selected" : ""}>${p.name}</option>`).join("")}</select>
    <label>运行条件</label>
    <select id="when">
      <option value="">始终执行下一节点</option>
      <option value="hasValidCities" ${edge.when === "hasValidCities" ? "selected" : ""}>仅当 hasValidCities 为 true</option>
      <option value="!hasValidCities" ${edge.when === "!hasValidCities" ? "selected" : ""}>仅当 hasValidCities 为 false</option>
    </select>
    <button type="button" id="delEdge">删除连线</button>`;
    inspector.querySelector("#fromPort").onchange = (e) => { edge.fromPort = e.target.value; drawWires(); };
    inspector.querySelector("#toPort").onchange = (e) => { edge.toPort = e.target.value; };
    inspector.querySelector("#when").onchange = (e) => { edge.when = e.target.value; };
    inspector.querySelector("#delEdge").onclick = () => {
        state.edges = state.edges.filter((item) => item.id !== edge.id);
        state.selected = null;
        render();
    };
}

async function runGraph() {
    logEl.textContent = "运行中…";
    const res = await fetch("/api/run", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ nodes: state.nodes, edges: state.edges }),
    });
    const data = await res.json();
    if (!data.ok) {
        logEl.textContent = data.error ?? "运行失败";
        return;
    }
    logEl.textContent = data.steps.map((step) => {
        const head = `${step.title} (${step.type})${step.skipped ? " [跳过]" : ""}`;
        const inputs = JSON.stringify(step.inputs, null, 2);
        const outputs = JSON.stringify(step.outputs, null, 2);
        return `${head}\n输入:\n${inputs}\n输出:\n${outputs}\n${step.message ?? ""}`;
    }).join("\n\n-----\n\n");
}

async function loadCatalog() {
    const [catalog, credentials] = await Promise.all([
        (await fetch("/api/catalog")).json(),
        (await fetch("/api/credentials")).json(),
    ]);
    state.system = catalog.system ?? [];
    state.plugins = catalog.plugins ?? [];
    state.catalog = catalog.nodes ?? [];
    state.issues = catalog.issues ?? [];
    state.pluginsRoot = catalog.pluginsRoot ?? "";
    state.credentials = credentials ?? [];
    renderPalette();
    if (state.nodes.length) {
        render();
    }
}

document.getElementById("btnExample").onclick = () => {
    const graph = exampleGraph();
    state.nodes = graph.nodes;
    state.edges = graph.edges;
    state.selected = { kind: "edge", id: "e1" };
    render();
};
document.getElementById("btnRun").onclick = runGraph;
document.getElementById("btnRefresh").onclick = async () => {
    logEl.textContent = "正在重新扫描系统节点和 plugins 目录…";
    await loadCatalog();
    logEl.textContent = `已刷新。系统 ${state.system.length} 个，插件 ${state.plugins.length} 个。`;
};

window.addEventListener("resize", drawWires);

(async function init() {
    await loadCatalog();
    document.getElementById("btnExample").click();
})();