// apps/api/src/routes/analysis.ts
// Seven REST endpoints under /api/analysis. All responses use the standard
// envelope { code, msg, data? } per the system contract.

import type { FastifyInstance } from "fastify";
import { z } from "zod";
import { basename, join } from "node:path";
import { mkdirSync, writeFileSync, existsSync, createReadStream } from "node:fs";
import { readdir, readFile } from "node:fs/promises";
import { randomUUID } from "node:crypto";
import JSZip from "jszip";

import type { Config } from "../config.js";
import type { Store, ItemRow } from "../queue/store.js";
import type { QueueRunner, OptionsSnapshot } from "../queue/runner.js";
import { detectModeFromZip } from "../analyzers/detect.js";

interface RouteDeps {
  store: Store;
  config: Config;
  runner: QueueRunner;
}

const ZIP_FILENAME_RE = /\.zip$/i;

function boundedNumber(min: number, max: number) {
  return z.preprocess((value) => {
    if (value === undefined) return value;
    const parsed = Number(value);
    if (!Number.isFinite(parsed)) return value;
    return Math.min(max, Math.max(min, parsed));
  }, z.number().min(min).max(max));
}

function boundedInteger(min: number, max: number) {
  return z.preprocess((value) => {
    if (value === undefined) return value;
    const parsed = Number(value);
    if (!Number.isFinite(parsed)) return value;
    return Math.min(max, Math.max(min, Math.round(parsed)));
  }, z.number().int().min(min).max(max));
}

// Whitelist of fields accepted for optionsSnapshot. The frontend is permitted
// to override the main analyzer model's API key (used for recommended_groups
// + recommended_rubrics generation). Judge keys remain backend-only via .env.
const OptionsSnapshotSchema = z
  .object({
    requestedMode: z.enum(["api", "mcp"]).optional(),
    model: z.string().optional(),
    baseURL: z.string().optional(),
    apiKey: z.string().optional(),
    apiMode: z.enum(["chat", "responses"]).optional(),
    concurrency: boundedInteger(1, 8).optional(),
    temperature: boundedNumber(0, 2).optional(),
    topP: boundedNumber(0, 1).optional(),
    maxTokens: boundedInteger(1, 131072).optional(),
    streaming: z.boolean().optional(),
    enableThinking: z.boolean().optional(),
    clearThinking: z.boolean().optional(),
    ruleProfile: z.string().optional(),
    optimizeTask: z.boolean().optional(),
    feedback: z.string().optional(),
    strictFullMarks: z.boolean().optional(),
    ignoreTaskComplexityForFullMarks: z.boolean().optional(),
    judge: z
      .object({
        model: z.string().optional(),
        baseURL: z.string().optional(),
        apiMode: z.enum(["chat", "responses"]).optional(),
        promptTemplate: z.string().optional(),
      })
      .strict()
      .optional(),
    rubricGeneration: z
      .object({
        model: z.string().optional(),
        baseURL: z.string().optional(),
        apiMode: z.enum(["chat", "responses"]).optional(),
      })
      .strict()
      .optional(),
  })
  .strict();

function ok(data: unknown) {
  return { code: 0, msg: "ok", data };
}

function errEnv(code: number, msg: string) {
  return { code, msg };
}

function publicItemView(row: ItemRow) {
  const progressByStatus: Record<string, number> = {
    queued: 0,
    running: 0.35,
    judging: 0.75,
    completed: 1,
    failed: 1,
    stopped: 1,
  };
  return {
    id: row.id,
    jobId: row.job_id,
    ord: row.ord,
    filename: row.filename,
    detectedMode: row.detected_mode,
    status: row.status,
    progress: progressByStatus[row.status] ?? 0,
    errorPreview: row.error_preview,
    attemptCount: row.attempt_count,
    lastStage: row.last_stage,
    hasExport: Boolean(row.export_zip_path),
    createdAt: row.created_at,
    updatedAt: row.updated_at,
  };
}

function attachmentHeader(filename: string): string {
  let fallback = basename(filename)
    .replace(/[^\w.-]+/g, "_")
    .replace(/^_+|_+$/g, "");
  if (!fallback || fallback.startsWith(".")) fallback = "download.zip";
  return `attachment; filename="${fallback}"; filename*=UTF-8''${encodeURIComponent(filename)}`;
}

async function readJsonArtifact(path: string | null): Promise<unknown | null> {
  if (!path || !existsSync(path)) return null;
  return JSON.parse(await readFile(path, "utf8"));
}

function finiteNumber(value: unknown): number | null {
  const parsed = Number(value);
  return Number.isFinite(parsed) ? parsed : null;
}

async function readJudgeHistory(config: Config, item: ItemRow) {
  const itemDir = join(config.exportDir, item.job_id, item.id);
  let entries: string[];
  try {
    entries = await readdir(itemDir);
  } catch {
    return [];
  }

  const files = entries
    .map((name) => {
      const match = /^judge-result-iter-(\d+)\.json$/.exec(name);
      return match ? { name, iteration: Number(match[1]) } : null;
    })
    .filter((entry): entry is { name: string; iteration: number } => Boolean(entry))
    .sort((a, b) => a.iteration - b.iteration);

  const history = [];
  for (const file of files) {
    const judgeResult = await readJsonArtifact(join(itemDir, file.name));
    if (!judgeResult || typeof judgeResult !== "object") continue;
    const result = judgeResult as Record<string, unknown>;
    history.push({
      iteration: file.iteration,
      score: finiteNumber(result.total_score),
      maxScore: finiteNumber(result.max_score) ?? 12,
      verdict: typeof result.verdict === "string" ? result.verdict : "",
      hasZeros: Boolean(result.has_zeros),
      judgeResult: result,
    });
  }
  return history;
}

interface PendingUpload {
  filename: string;
  buffer: Buffer;
  autoDetectedMode: "api" | "mcp";
}

function normalizeRequestedMode(value: unknown): "api" | "mcp" | null {
  return value === "api" || value === "mcp" ? value : null;
}

export async function registerAnalysisRoutes(
  app: FastifyInstance,
  deps: RouteDeps
): Promise<void> {
  const { store, config, runner } = deps;

  // ── POST /api/analysis/jobs ────────────────────────────────────────────
  // Multipart upload: 1..N .zip files. The selected page can force api/mcp
  // mode via requestedMode; otherwise each zip is auto-detected.
  app.post("/api/analysis/jobs", async (req, reply) => {
    if (!req.isMultipart()) {
      reply.code(400).send(errEnv(400, "Expected multipart/form-data"));
      return;
    }

    // Step 1: read + validate all parts in memory (bounded by maxUploadMB +
    // maxBatchFiles via fastify-multipart limits).
    const pending: PendingUpload[] = [];
    let requestedMode: "api" | "mcp" | null = null;
    try {
      const parts = req.parts();
      for await (const part of parts) {
        if (part.type === "field") {
          if (part.fieldname === "requestedMode") {
            const normalized = normalizeRequestedMode(part.value);
            if (!normalized) {
              reply.code(400).send(errEnv(400, "requestedMode 只能是 api 或 mcp"));
              return;
            }
            requestedMode = normalized;
          }
          continue;
        }
        if (!part.filename) continue;
        if (!ZIP_FILENAME_RE.test(part.filename)) {
          reply.code(400).send(errEnv(400, `仅支持 .zip 文件：${part.filename}`));
          return;
        }
        const buf = await part.toBuffer();
        let detected: { mode: "api" | "mcp" };
        try {
          detected = await detectModeFromZip(buf);
        } catch (e) {
          const msg = e instanceof Error ? e.message : "ZIP 校验失败";
          reply.code(400).send(errEnv(400, `${part.filename}: ${msg}`));
          return;
        }
        pending.push({
          filename: part.filename,
          buffer: buf,
          autoDetectedMode: detected.mode,
        });
      }
    } catch (e) {
      app.log.error({ err: e }, "Failed to consume multipart upload");
      reply.code(500).send(errEnv(500, "上传读取失败"));
      return;
    }

    if (pending.length === 0) {
      reply.code(400).send(errEnv(400, "未收到任何 .zip 文件"));
      return;
    }
    if (pending.length > config.maxBatchFiles) {
      reply
        .code(400)
        .send(
          errEnv(
            400,
            `单次最多上传 ${config.maxBatchFiles} 个 zip，本次：${pending.length}`
          )
        );
      return;
    }

    // Step 2: create job + persist files under canonical job dir.
    const job = await store.createJob({});
    const jobUploadDir = join(config.uploadDir, job.id);
    try {
      mkdirSync(jobUploadDir, { recursive: true });
    } catch (e) {
      app.log.error({ err: e, jobUploadDir }, "Failed to create upload dir");
      reply.code(500).send(errEnv(500, "上传目录创建失败"));
      return;
    }

    const itemRows: ItemRow[] = [];
    for (const [idx, p] of pending.entries()) {
      const uploadPath = join(jobUploadDir, `${randomUUID()}.zip`);
      writeFileSync(uploadPath, p.buffer);
      const row = await store.createItem({
        jobId: job.id,
        ord: idx + 1,
        filename: p.filename,
        uploadPath,
        detectedMode: requestedMode ?? p.autoDetectedMode,
      });
      itemRows.push(row);
    }

    reply.send(
      ok({
        jobId: job.id,
        items: itemRows.map(publicItemView),
      })
    );
  });

  // ── GET /api/analysis/jobs/:jobId ──────────────────────────────────────
  app.get<{ Params: { jobId: string } }>(
    "/api/analysis/jobs/:jobId",
    async (req, reply) => {
      const job = await store.getJob(req.params.jobId);
      if (!job) {
        reply.code(404).send(errEnv(404, "Job not found"));
        return;
      }
      const items = (await store.listItemsByJob(job.id)).map(publicItemView);
      reply.send(
        ok({
          id: job.id,
          status: job.status,
          createdAt: job.created_at,
          updatedAt: job.updated_at,
          items,
        })
      );
    }
  );

  // ── POST /api/analysis/jobs/:jobId/start ───────────────────────────────
  app.post<{
    Params: { jobId: string };
    Body: { optionsSnapshot?: unknown };
  }>("/api/analysis/jobs/:jobId/start", async (req, reply) => {
    const job = await store.getJob(req.params.jobId);
    if (!job) {
      reply.code(404).send(errEnv(404, "Job not found"));
      return;
    }
    if (job.status === "running") {
      reply.code(409).send(errEnv(409, "Job 已经在运行中"));
      return;
    }

    const rawSnapshot =
      (req.body as { optionsSnapshot?: unknown } | undefined)?.optionsSnapshot ??
      {};
    const parsed = OptionsSnapshotSchema.safeParse(rawSnapshot);
    if (!parsed.success) {
      reply
        .code(400)
        .send(errEnv(400, `optionsSnapshot 校验失败：${parsed.error.message}`));
      return;
    }
    const snapshot: OptionsSnapshot = parsed.data;

    await store.updateJobOptions(job.id, snapshot);
    runner.scheduleJob(job.id);

    reply.send(ok({ jobId: job.id, status: "running" }));
  });

  // ── POST /api/analysis/jobs/:jobId/cancel ──────────────────────────────
  app.post<{ Params: { jobId: string } }>(
    "/api/analysis/jobs/:jobId/cancel",
    async (req, reply) => {
      const job = await store.getJob(req.params.jobId);
      if (!job) {
        reply.code(404).send(errEnv(404, "Job not found"));
        return;
      }
      runner.cancelJob(job.id);
      reply.send(ok({ jobId: job.id, status: "cancel-requested" }));
    }
  );

  // ── POST /api/analysis/jobs/:jobId/items/:itemId/retry ─────────────────
  app.post<{ Params: { jobId: string; itemId: string } }>(
    "/api/analysis/jobs/:jobId/items/:itemId/retry",
    async (req, reply) => {
      const item = await store.getItem(req.params.itemId);
      if (!item || item.job_id !== req.params.jobId) {
        reply.code(404).send(errEnv(404, "Item not found"));
        return;
      }
      await runner.retryItem(item.id);
      reply.send(ok({ itemId: item.id, status: "queued" }));
    }
  );

  // ── GET /api/analysis/jobs/:jobId/items/:itemId/result ────────────────
  // Returns the generated JSON artifacts so the frontend can render concrete
  // analysis details even though the heavy work runs in the backend.
  app.get<{ Params: { jobId: string; itemId: string } }>(
    "/api/analysis/jobs/:jobId/items/:itemId/result",
    async (req, reply) => {
      const item = await store.getItem(req.params.itemId);
      if (!item || item.job_id !== req.params.jobId) {
        reply.code(404).send(errEnv(404, "Item not found"));
        return;
      }

      try {
        const evidenceBundle = (await readJsonArtifact(item.evidence_path)) as
          | {
              flags?: unknown;
              evidence?: unknown;
              analyzerResult?: unknown;
              iterationMemory?: unknown;
            }
          | null;
        const taskPackage = await readJsonArtifact(item.task_package_path);
        const judgeHistory = await readJudgeHistory(config, item);
        const latestJudgeResult = judgeHistory.at(-1)?.judgeResult ?? null;
        const judgeResult = (await readJsonArtifact(item.judge_result_path)) ?? latestJudgeResult;
        reply.send(
          ok({
            item: publicItemView(item),
            flags: evidenceBundle?.flags ?? [],
            evidence: evidenceBundle?.evidence ?? null,
            analyzerResult: evidenceBundle?.analyzerResult ?? null,
            iterationMemory: evidenceBundle?.iterationMemory ?? null,
            taskPackage,
            judgeResult,
            judgeHistory,
          })
        );
      } catch (e) {
        app.log.error({ err: e, itemId: item.id }, "Failed to read item artifacts");
        reply.code(500).send(errEnv(500, "分析结果读取失败"));
      }
    }
  );

  // ── GET /api/analysis/jobs/:jobId/items/:itemId/download ───────────────
  app.get<{ Params: { jobId: string; itemId: string } }>(
    "/api/analysis/jobs/:jobId/items/:itemId/download",
    async (req, reply) => {
      const item = await store.getItem(req.params.itemId);
      if (!item || item.job_id !== req.params.jobId) {
        reply.code(404).send(errEnv(404, "Item not found"));
        return;
      }
      if (!item.export_zip_path || !existsSync(item.export_zip_path)) {
        reply.code(404).send(errEnv(404, "导出文件尚未生成"));
        return;
      }
      const downloadName =
        item.filename.replace(ZIP_FILENAME_RE, "") + ".task-package.zip";
      reply
        .header("Content-Type", "application/zip")
        .header("Content-Disposition", attachmentHeader(downloadName));
      return reply.send(createReadStream(item.export_zip_path));
    }
  );

  // ── GET /api/analysis/jobs/:jobId/download-all ─────────────────────────
  // Bundles all completed items into a single zip-of-zips on the fly.
  app.get<{ Params: { jobId: string } }>(
    "/api/analysis/jobs/:jobId/download-all",
    async (req, reply) => {
      const job = await store.getJob(req.params.jobId);
      if (!job) {
        reply.code(404).send(errEnv(404, "Job not found"));
        return;
      }
      const items = await store.listItemsByJob(job.id);
      const exportable = items.filter(
        (it) => it.export_zip_path && existsSync(it.export_zip_path)
      );
      if (exportable.length === 0) {
        reply.code(404).send(errEnv(404, "暂无可下载的导出项"));
        return;
      }

      const zip = new JSZip();
      const used = new Set<string>();
      for (const it of exportable) {
        const baseName =
          it.filename.replace(ZIP_FILENAME_RE, "") + ".task-package.zip";
        let entryName = baseName;
        let i = 1;
        while (used.has(entryName)) {
          entryName = `${baseName.replace(/\.task-package\.zip$/i, "")}-${i}.task-package.zip`;
          i += 1;
        }
        used.add(entryName);
        const content = await readFile(it.export_zip_path!);
        zip.file(entryName, content);
      }
      const buf = await zip.generateAsync({
        type: "nodebuffer",
        compression: "DEFLATE",
        compressionOptions: { level: 6 },
      });
      reply
        .header("Content-Type", "application/zip")
        .header(
          "Content-Disposition",
          attachmentHeader(`all-results-${job.id.slice(0, 8)}.zip`)
        );
      reply.send(buf);
    }
  );
}