const fs = require("fs");
const path = require("path");

const { ensureKnowledgeDirs, knowledgeRoot } = require("./file_knowledge");

function generateKnowledgeFiles(rootDir = process.cwd()) {
  const root = ensureKnowledgeDirs(rootDir);
  const generatedAt = new Date().toISOString();
  const written = [];
  const coreFile = path.join(root, "core", "lumi-core.md");
  const coreMarkdown = buildCoreKnowledge(rootDir, generatedAt);
  if (writeGeneratedFile(coreFile, coreMarkdown)) {
    written.push(path.relative(rootDir, coreFile));
  }
  for (const plugin of discoverPlugins(rootDir)) {
    const pluginFile = path.join(root, "plugins", `${slugify(plugin.id)}.md`);
    const pluginMarkdown = buildPluginKnowledge(plugin, generatedAt);
    if (writeGeneratedFile(pluginFile, pluginMarkdown)) {
      written.push(path.relative(rootDir, pluginFile));
    }
  }
  return written;
}

function buildCoreKnowledge(rootDir, generatedAt) {
  const packageJson = readJson(path.join(rootDir, "package.json"));
  const readme = readText(path.join(rootDir, "README.md"));
  const routes = discoverCoreRoutes(rootDir);
  const routeReference = buildRouteReference(routes);
  return frontmatter({
    id: "core.lumi",
    title: packageJson.name || "Lumi Core",
    scope: "core",
    status: "active",
    priority: 20,
    visibility: "user",
    category: "Core",
    tags: "core, routes, commands, settings",
    generated: true,
    editable: false,
    updated_at: generatedAt
  }) + [
    `# ${packageJson.name || "Lumi Core"}`,
    "",
    packageJson.description || "Lumi is the core web UI and bot runtime.",
    "",
    "## Runtime",
    "",
    `Package: ${packageJson.name || "unknown"}`,
    packageJson.version ? `Version: ${packageJson.version}` : "",
    packageJson.main ? `Entry point: ${packageJson.main}` : "",
    "",
    "## Routes",
    "",
    routes.length ? routes.map((route) => `- ${route.method.toUpperCase()} ${route.path}`).join("\n") : "- No core routes detected.",
    "",
    "## Route Reference",
    "",
    routeReference || "No route details detected.",
    "",
    "## README Summary",
    "",
    excerpt(readme, 1800) || "No README summary available."
  ].filter((line) => line !== "").join("\n");
}

function buildPluginKnowledge(plugin, generatedAt) {
  const routeLines = plugin.routes.length
    ? plugin.routes.map((route) => `- ${route.method ? `${route.method.toUpperCase()} ` : ""}${route.path}`).join("\n")
    : "- No plugin routes detected.";
  const routeReference = buildRouteReference(plugin.routes);
  const commandLines = plugin.commands.length
    ? plugin.commands.map((command) => `- ${command}`).join("\n")
    : "- No plugin command triggers detected.";
  return frontmatter({
    id: `plugin.${plugin.id}`,
    title: plugin.name || plugin.id,
    scope: "plugins",
    status: "active",
    priority: 10,
    visibility: "user",
    category: "Plugin",
    tags: ["plugin", plugin.id, ...(plugin.keywords || [])].join(", "),
    generated: true,
    editable: false,
    updated_at: generatedAt
  }) + [
    `# ${plugin.name || plugin.id}`,
    "",
    plugin.description || "No plugin description is available.",
    "",
    "## Metadata",
    "",
    `Plugin ID: ${plugin.id}`,
    plugin.version ? `Version: ${plugin.version}` : "",
    plugin.author ? `Author: ${plugin.author}` : "",
    plugin.enabled === false ? "Default state: disabled" : "Default state: enabled",
    "",
    "## Web Routes",
    "",
    routeLines,
    "",
    "## Route Reference",
    "",
    routeReference || "No route details detected.",
    "",
    "## Commands",
    "",
    commandLines,
    "",
    "## Source",
    "",
    `Plugin folder: plugins/${plugin.folder}`
  ].filter((line) => line !== "").join("\n");
}

function discoverPlugins(rootDir) {
  const pluginsDir = path.join(rootDir, "plugins");
  if (!fs.existsSync(pluginsDir)) return [];
  return fs.readdirSync(pluginsDir, { withFileTypes: true })
    .filter((entry) => entry.isDirectory())
    .map((entry) => {
      const dir = path.join(pluginsDir, entry.name);
      const manifest = readJson(path.join(dir, "plugin.json"));
      if (!manifest.id && !manifest.name) return null;
      const source = readText(path.join(dir, "index.js"));
      return {
        id: cleanText(manifest.id || entry.name, 120),
        folder: entry.name,
        name: cleanText(manifest.name || manifest.label || manifest.id || entry.name, 180),
        version: cleanText(manifest.version, 80),
        description: cleanText(manifest.description, 800),
        author: cleanText(manifest.author, 180),
        enabled: manifest.enabled,
        keywords: Array.isArray(manifest.keywords) ? manifest.keywords.map((item) => cleanText(item, 80)).filter(Boolean) : [],
        routes: discoverPluginRoutes(source, manifest.id || entry.name),
        commands: discoverCommandTriggers(source)
      };
    })
    .filter(Boolean)
    .sort((a, b) => a.id.localeCompare(b.id));
}

function discoverCoreRoutes(rootDir) {
  const server = readText(path.join(rootDir, "src", "web", "server.js"));
  const routes = [];
  for (const match of server.matchAll(/\bapp\.(get|post|put|patch|delete)\(\s*["'`]([^"'`]+)["'`]/g)) {
    const source = extractCallExpression(server, match.index);
    routes.push({
      method: match[1],
      path: match[2],
      details: analyzeRouteSource(source, match[1], match[2])
    });
  }
  return uniqueRoutes(routes).slice(0, 200);
}

function discoverPluginRoutes(source, pluginId) {
  const routes = [];
  const mountPaths = discoverMountPaths(source, pluginId);
  for (const match of source.matchAll(/\bweb\.mount\(\s*["'`]([^"'`]+)["'`]/g)) {
    routes.push({
      method: "",
      path: normalizeTemplatePath(match[1], pluginId),
      details: {
        purpose: "Mounts the plugin router at this base WebUI path.",
        inputs: [],
        response: "Plugin router mount point.",
        access: "Access is controlled by the mount options and individual plugin routes.",
        sideEffects: "No direct route action; child routes handle requests.",
        limits: "Mount metadata is inferred from static source scanning."
      }
    });
  }
  for (const match of source.matchAll(/\brouter\.(get|post|put|patch|delete)\(\s*["'`]([^"'`]+)["'`]/g)) {
    const sourceSnippet = extractCallExpression(source, match.index);
    const routePath = normalizeTemplatePath(match[2], pluginId);
    const bases = mountPaths.length ? mountPaths : [`/plugins/${pluginId}`];
    for (const base of bases) {
      const fullPath = joinRoutePath(base, routePath);
      routes.push({
        method: match[1],
        path: fullPath,
        details: analyzeRouteSource(sourceSnippet, match[1], fullPath)
      });
    }
  }
  return uniqueRoutes(routes).slice(0, 100);
}

function discoverMountPaths(source, pluginId) {
  const paths = [];
  for (const match of source.matchAll(/\bweb\.mount\(\s*["'`]([^"'`]+)["'`]/g)) {
    paths.push(normalizeTemplatePath(match[1], pluginId));
  }
  return Array.from(new Set(paths)).filter(Boolean);
}

function normalizeTemplatePath(value, pluginId) {
  return String(value || "").replace(/\$\{PLUGIN_ID\}/g, pluginId);
}

function joinRoutePath(base, child) {
  const normalizedBase = String(base || "").replace(/\/+$/, "") || "/";
  const normalizedChild = String(child || "").replace(/^\/+/, "");
  if (!normalizedChild) return normalizedBase;
  if (normalizedChild === "/") return normalizedBase;
  return `${normalizedBase}/${normalizedChild}`.replace(/\/+/g, "/");
}

function discoverCommandTriggers(source) {
  const triggers = new Set();
  for (const match of source.matchAll(/\btrigger\s*:\s*["'`]([^"'`]+)["'`]/g)) {
    triggers.add(match[1]);
  }
  for (const match of source.matchAll(/\bcommand\s*:\s*["'`]([^"'`]+)["'`]/g)) {
    triggers.add(match[1]);
  }
  return Array.from(triggers).sort().slice(0, 100);
}

function writeGeneratedFile(filePath, content) {
  if (!canOverwriteGeneratedFile(filePath)) return false;
  fs.mkdirSync(path.dirname(filePath), { recursive: true });
  fs.writeFileSync(filePath, `${content.trim()}\n`);
  return true;
}

function canOverwriteGeneratedFile(filePath) {
  if (!fs.existsSync(filePath)) return true;
  const text = readText(filePath);
  if (/generated\s*:\s*false/i.test(text)) return false;
  if (/editable\s*:\s*true/i.test(text)) return false;
  return true;
}

function uniqueRoutes(routes) {
  const seen = new Set();
  return routes.filter((route) => {
    const key = `${route.method}:${route.path}`;
    if (seen.has(key)) return false;
    seen.add(key);
    return true;
  });
}

function buildRouteReference(routes) {
  if (!routes.length) return "";
  return routes.map((route) => {
    const details = route.details || analyzeRouteSource("", route.method, route.path);
    return [
      `### ${route.method ? route.method.toUpperCase() : "MOUNT"} ${route.path}`,
      "",
      `- Purpose: ${details.purpose}`,
      `- Inputs: ${details.inputs.length ? details.inputs.join("; ") : "No request parameters detected by static analysis."}`,
      `- Response format: ${details.response}`,
      `- Access: ${details.access}`,
      `- Side effects: ${details.sideEffects}`,
      `- Limits/notes: ${details.limits}`
    ].join("\n");
  }).join("\n\n");
}

function analyzeRouteSource(source, method, routePath) {
  const bodyFields = findRequestFields(source, "body");
  const queryFields = findRequestFields(source, "query");
  const paramFields = Array.from(new Set([
    ...extractPathParams(routePath),
    ...findRequestFields(source, "params")
  ])).sort();
  const inputs = [];
  if (paramFields.length) inputs.push(`path params: ${paramFields.map((field) => `\`${field}\``).join(", ")}`);
  if (queryFields.length) inputs.push(`query: ${queryFields.map((field) => `\`${field}\``).join(", ")}`);
  if (bodyFields.length) inputs.push(`body: ${bodyFields.map((field) => `\`${field}\``).join(", ")}`);
  if (/\breq\.file\b|\breq\.files\b|\bupload\.(single|array|fields)\(/.test(source)) {
    inputs.push("file upload: multipart form file data");
  }
  if (!bodyFields.length && /\breq\.body\b/.test(source)) {
    inputs.push("body: full submitted body is passed to a helper; exact fields are defined by the matching form/service");
  }
  if (!queryFields.length && /\breq\.query\b/.test(source)) {
    inputs.push("query: full query object is passed to a helper; exact fields are defined by the matching view/service");
  }
  if (!paramFields.length && /\breq\.params\b/.test(source)) {
    inputs.push("path params: full params object is used; exact keys come from the route path");
  }
  const response = describeResponseFormat(source, method, routePath);
  return {
    purpose: describeRoutePurpose(source, method, routePath, response),
    inputs,
    response,
    access: describeAccess(source, routePath),
    sideEffects: describeSideEffects(source, method, bodyFields),
    limits: describeRouteLimits(source, method, routePath)
  };
}

function findRequestFields(source, bucket) {
  const fields = new Set();
  const dotPattern = new RegExp(`\\breq\\.${bucket}\\.([A-Za-z_$][A-Za-z0-9_$]*)`, "g");
  for (const match of source.matchAll(dotPattern)) {
    fields.add(match[1]);
  }
  const bracketPattern = new RegExp(`\\breq\\.${bucket}\\s*\\[\\s*["'\`]([^"'\`]+)["'\`]\\s*\\]`, "g");
  for (const match of source.matchAll(bracketPattern)) {
    fields.add(match[1]);
  }
  return Array.from(fields).sort().slice(0, 40);
}

function extractPathParams(routePath) {
  const fields = new Set();
  for (const match of String(routePath || "").matchAll(/:([A-Za-z0-9_]+)/g)) {
    fields.add(match[1]);
  }
  return Array.from(fields);
}

function describeResponseFormat(source, method, routePath) {
  const formats = [];
  if (/\bres\.render\(/.test(source)) formats.push("HTML page rendered from an EJS view");
  if (/\brenderAdmin\(/.test(source)) formats.push("HTML page rendered by a helper");
  if (/\bres\.json\(/.test(source)) formats.push("JSON response");
  if (/\bres\.redirect\(/.test(source)) formats.push("HTTP redirect after handling the request");
  if (/\bres\.download\(/.test(source)) formats.push("file download");
  if (/\bres\.sendFile\(/.test(source)) formats.push("static file response");
  if (/\bres\.write\(/.test(source) || /text\/event-stream|subscribeWebEvents/.test(source)) formats.push("streaming event response");
  if (/\bres\.send\(/.test(source) && !formats.length) formats.push("plain or HTML response");
  if (!formats.length && !method) return "Router mount; child routes provide concrete responses.";
  if (!formats.length && String(routePath).startsWith("/api/")) return "API response; exact schema was not detected statically.";
  if (!formats.length && method === "get") return "HTML or data response; exact format was not detected statically.";
  if (!formats.length) return "Form/action response; exact format was not detected statically.";
  return Array.from(new Set(formats)).join("; ");
}

function describeRoutePurpose(source, method, routePath, response) {
  const pathText = String(routePath || "");
  const normalized = pathText.replace(/[:/._-]+/g, " ").trim();
  if (!method) return "Registers a plugin route namespace.";
  if (/\/api\/events/.test(pathText)) return "Streams live WebUI event notifications to the browser.";
  const pluginAdminMatch = pathText.match(/^\/plugins\/([^/]+)\/admin(?:\/(.+))?$/);
  if (pluginAdminMatch) {
    const pluginId = pluginAdminMatch[1];
    const action = pluginAdminMatch[2] ? pluginAdminMatch[2].replace(/[:/._-]+/g, " ").trim() : "";
    if (method === "get") return `Renders the ${pluginId} plugin administration page${action ? ` for ${action}` : ""}.`;
    return `Processes the ${pluginId} plugin administration action${action ? ` for ${action}` : ""}.`;
  }
  const pluginPageMatch = pathText.match(/^\/plugins\/([^/]+)(?:\/(.+))?$/);
  if (pluginPageMatch) {
    const pluginId = pluginPageMatch[1];
    const action = pluginPageMatch[2] ? pluginPageMatch[2].replace(/[:/._-]+/g, " ").trim() : "";
    if (method === "get") return `Renders or serves the ${pluginId} plugin page${action ? ` for ${action}` : ""}.`;
    return `Processes the ${pluginId} plugin action${action ? ` for ${action}` : ""}.`;
  }
  if (/\/api\/users\/search/.test(pathText)) return "Searches known linked Lumi users for shared user-lookup fields.";
  if (/\/api\/placeholders\/catalog/.test(pathText)) return "Returns placeholder suggestions available to the current user and field policy.";
  if (/\/api\/placeholders\/preview/.test(pathText)) return "Previews placeholder rendering for a submitted template without saving it.";
  if (/\/feedback/.test(pathText) && method === "post") return "Creates, updates, comments on, exports, or manages feedback records depending on the action path.";
  if (/\/admin\/updates/.test(pathText)) return "Checks, applies, reverts, or reports update state for core or plugin updates.";
  if (/\/admin\/settings/.test(pathText)) return method === "get" ? "Renders the core settings page." : "Saves core settings from the admin settings form.";
  if (/\/auth\//.test(pathText)) return "Starts, completes, or cancels a platform authentication/linking flow.";
  if (/\/setup/.test(pathText)) return "Guides first-time platform setup and verification.";
  if (/\/commands/.test(pathText)) return method === "get" ? "Displays configured bot commands." : "Creates, updates, previews, toggles, or deletes custom commands.";
  if (/^\/admin\/plugins/.test(pathText)) return "Manages installed plugins, plugin uploads, installs, updates, or plugin enablement.";
  if (/\/plugins/.test(pathText)) return "Displays or handles plugin-specific WebUI functionality.";
  if (/\/health/.test(pathText)) return "Returns runtime health information.";
  if (/\/logs/.test(pathText)) return "Displays, downloads, or manages application logs.";
  if (/\/stats/.test(pathText)) return "Displays user or community statistics.";
  if (/\/leaderboards/.test(pathText)) return "Displays leaderboard data.";
  if (/\bres\.render\(/.test(source)) return `Renders the ${normalized || "requested"} WebUI page.`;
  if (/\bres\.json\(/.test(source)) return `Provides ${normalized || "route"} data as JSON.`;
  if (method === "post") return `Processes the ${normalized || "route"} action and stores or applies submitted form data.`;
  return `Handles ${normalized || "this route"}.`;
}

function describeAccess(source, routePath) {
  const signals = [];
  if (/\brequireOkf(Edit|Management)\b/.test(source)) {
    signals.push("OKF editor or manager permission required");
  }
  if (/\brequireOkfReview\b|\brequireOkfImplement\b/.test(source)) {
    signals.push("higher OKF review or implementation permission may be required");
  }
  if (/\brequireAdmin\b|\.isAdmin\b|hasAccess\([^)]*admin/.test(source) || /\/admin(\/|$)/.test(routePath)) {
    signals.push("admin access expected");
  }
  if (/\brequireMod\b|\.isMod\b|hasAccess\([^)]*mod/.test(source) || /\/moderator(\/|$)/.test(routePath)) {
    signals.push("moderator access may be required");
  }
  if (/\brequire(Login|Auth)\b|\breq\.session\.user\b|authRequired/.test(source)) {
    signals.push("logged-in session required or used");
  }
  if (/\bcanAccess\b/.test(source)) {
    signals.push("mount-level canAccess predicate applies");
  }
  if (!signals.length && /^\/api\//.test(routePath)) return "API route; access requirements were not fully detected by static analysis.";
  if (!signals.length) return "No explicit access guard detected in the route handler; check surrounding router/mount middleware.";
  return Array.from(new Set(signals)).join("; ");
}

function describeSideEffects(source, method, bodyFields) {
  const effects = [];
  if (/\bset[A-Z]|\bsetSetting\b|\bsave[A-Z]|\bupdate[A-Z]|\bcreate[A-Z]|\bdelete[A-Z]|\bremove[A-Z]|\binstall[A-Z]|\bapply[A-Z]|\brevert[A-Z]|\brestore[A-Z]|\bgrant[A-Z]|\brevoke[A-Z]/.test(source)) {
    effects.push("writes or mutates server-side state");
  }
  if (/\bfs\.(writeFileSync|rmSync|mkdirSync|renameSync|copyFileSync)\b/.test(source)) effects.push("writes files");
  if (/\bdb\.(prepare|exec)\b|\.run\(/.test(source)) effects.push("writes database state when the called service mutates data");
  if (/\bpublishWebEvent\b|subscribeWebEvents/.test(source)) effects.push("publishes or streams live WebUI events");
  if (/\brequestRestart\b|process\.exit/.test(source)) effects.push("may restart or stop runtime processes");
  if (method === "get" && !effects.length) return "Usually read-only.";
  if (method === "post" && !effects.length && bodyFields.length) return "Consumes submitted data; state mutation happens in called helpers if present.";
  if (method === "post" && !effects.length) return "Action route; side effects were not detected statically.";
  return effects.length ? Array.from(new Set(effects)).join("; ") : "No side effects detected statically.";
}

function describeRouteLimits(source, method, routePath) {
  const notes = ["Generated from static route source analysis; confirm exact behavior in the handler before changing integrations."];
  if (/\bcleanText\b|slice\(0,\s*\d+|limitFromBody|boundedInt|boundedNumber|clampInt/.test(source)) {
    notes.push("Input length or numeric bounds are enforced by helper functions in the handler.");
  }
  if (/\btry\b[\s\S]*\bcatch\b/.test(source)) {
    notes.push("Errors are caught and usually returned as a flash message, JSON error, or error page.");
  }
  if (method === "post" && !/^\/api\//.test(routePath)) {
    notes.push("Most non-API POST routes are browser form submissions and usually redirect after completion.");
  }
  if (/\/api\//.test(routePath)) {
    notes.push("API consumers should expect JSON unless the response format says otherwise.");
  }
  return notes.join(" ");
}

function extractCallExpression(source, startIndex) {
  const start = source.indexOf("(", startIndex);
  if (start === -1) return source.slice(startIndex, startIndex + 1200);
  let depth = 0;
  let quote = "";
  let escaped = false;
  for (let index = start; index < source.length; index += 1) {
    const char = source[index];
    if (quote) {
      if (escaped) {
        escaped = false;
      } else if (char === "\\") {
        escaped = true;
      } else if (char === quote) {
        quote = "";
      }
      continue;
    }
    if (char === "\"" || char === "'" || char === "`") {
      quote = char;
      continue;
    }
    if (char === "(") {
      depth += 1;
    } else if (char === ")") {
      depth -= 1;
      if (depth === 0) {
        return source.slice(startIndex, index + 1);
      }
    }
  }
  return source.slice(startIndex, startIndex + 4000);
}

function frontmatter(values) {
  const lines = ["---"];
  for (const [key, value] of Object.entries(values)) {
    if (value === "" || value === null || value === undefined) continue;
    lines.push(`${key}: ${frontmatterValue(value)}`);
  }
  lines.push("---", "");
  return lines.join("\n");
}

function frontmatterValue(value) {
  if (typeof value === "boolean" || typeof value === "number") return String(value);
  const text = String(value).replace(/\n/g, " ");
  return /[:#[\]{}"'\\]|^\s|\s$/.test(text) ? JSON.stringify(text) : text;
}

function readJson(filePath) {
  try {
    return JSON.parse(fs.readFileSync(filePath, "utf8"));
  } catch {
    return {};
  }
}

function readText(filePath) {
  try {
    return fs.readFileSync(filePath, "utf8");
  } catch {
    return "";
  }
}

function excerpt(value, limit) {
  return cleanText(value, limit).split("\n").filter((line) => line.trim()).slice(0, 12).join("\n");
}

function slugify(value) {
  return cleanText(value, 180)
    .toLowerCase()
    .replace(/[^a-z0-9]+/g, "-")
    .replace(/^-+|-+$/g, "") || "entry";
}

function cleanText(value, maximum = 4000) {
  return String(value || "").replace(/\r\n?/g, "\n").trim().slice(0, maximum);
}

module.exports = {
  buildCoreKnowledge,
  buildPluginKnowledge,
  discoverPlugins,
  generateKnowledgeFiles
};