import { initTRPC } from "@trpc/server";
import { EventEmitter, on } from "node:events";
import { getConfig } from "./config";
import { errorMessage } from "@/lib/utils/error";
import {
  PublishInputSchema,
  UpdateInputSchema,
  type ProgressEvent,
  type PlatformResult,
  type PublishResult,
  platforms,
  type PlatformContext,
  type PlatformAdaptor,
  type PublishInput,
  type UpdateInput,
  type ExistingRelease,
  PublishResultSchema,
  ProgressEventSchema,
} from "./publish.schemas";
import {
  publishModrinthVersion,
  updateModrinthVersion,
  listExistingModrinth,
  modrinthMatchKey,
} from "./platforms/modrinth";
import {
  publishCurseForgeVersion,
  updateCurseForgeVersion,
  listExistingCurseForge,
  curseForgeMatchKey,
} from "./platforms/curseforge";
import { computeVersionRanges, type McVersionEntry } from "@/lib/utils/mcVersion";
import { getCurseForgeMcVersions, getModrinthMcVersions } from "./meta";
import { readAsFile } from "@/lib/utils/file";
import { Template } from "@/lib/utils/template";
import { buildJarPath } from "@/lib/utils/format";

export const platformAdaptors: {
  [key in typeof platforms[number]]: PlatformAdaptor
} = {
  modrinth: {
    publish: publishModrinthVersion,
    update: updateModrinthVersion,
    listExisting: listExistingModrinth,
    matchKey: modrinthMatchKey,
    getGameVersions: getModrinthMcVersions,
  },
  curseforge: {
    publish: publishCurseForgeVersion,
    update: updateCurseForgeVersion,
    listExisting: listExistingCurseForge,
    matchKey: curseForgeMatchKey,
    getGameVersions: getCurseForgeMcVersions,
  },
};

// ── tRPC init ──────────────────────────────────────────

const t = initTRPC.create();

// ── Shared EventEmitter for progress ───────────────────

const ee = new EventEmitter();

// ── Platform orchestrator ──────────────────────────────

/**
 * 计算勾选版本的兼容范围条目（发布与更新流程共用）。
 * 范围必须基于完整项目版本列表计算，勾选只决定处理哪些条目。
 */
async function computeSelectedEntries(
  platform: typeof platforms[number],
  selectedMcVersions: string[],
  ctx: PlatformContext<UpdateInput>,
): Promise<McVersionEntry[]> {
  const selected = new Set(selectedMcVersions);
  const entries = computeVersionRanges(
    ctx.input.allMcVersions,
    await platformAdaptors[platform].getGameVersions(),
    ctx.input.cutoffMcVersion
  ).filter((e) => selected.has(e.version));
  if (entries.length !== selected.size) {
    throw new Error("勾选版本与项目版本列表不一致，请刷新后重试");
  }
  return entries;
}

/** 平台准备阶段失败的兜底：记为该平台全部失败并发出 failed 事件，
 * 否则前端进度条会停在 running 假象里，错误也被吞掉。 */
function failPlatformPreparation(
  platform: typeof platforms[number],
  total: number,
  result: PlatformResult,
  err: unknown,
  logPrefix: string,
): void {
  const msg = errorMessage(err);
  console.error(`[${logPrefix}] ${platform} 准备阶段失败:`, err);
  result.fail = total;
  result.errors.push(msg);
  ee.emit("progress", {
    platform,
    current: 0,
    total,
    status: "failed",
    errors: result.errors,
  } satisfies ProgressEvent);
}

async function runPlatform(
  platform: typeof platforms[number],
  mcVersions: PublishInput["mcVersions"][keyof PublishInput["mcVersions"]],
  ctx: PlatformContext,
): Promise<PlatformResult> {
  const result: PlatformResult = { success: 0, fail: 0, errors: [] };
  const total = mcVersions.length;

  if (total === 0) {
    ee.emit("progress", {
      platform,
      current: 0,
      total: 0,
      status: "completed",
      errors: [],
    } satisfies ProgressEvent);
    return result;
  }

  // Emit initial running state
  ee.emit("progress", {
    platform,
    current: 0,
    total,
    status: "running",
    errors: [],
  } satisfies ProgressEvent);

  const publishFn = platformAdaptors[platform].publish;

  // 平台准备阶段（元数据拉取 + 版本范围计算）。此处异常不在逐版本的
  // try/catch 内，必须单独兜底。
  let mcVersionEntries: McVersionEntry[];
  try {
    mcVersionEntries = await computeSelectedEntries(
      platform,
      mcVersions.map((v) => v.mc_version),
      ctx,
    );
  } catch (err) {
    failPlatformPreparation(platform, total, result, err, "publish");
    return result;
  }

  const primaryFileTemplate = new Template(ctx.config.filename_format);
  const sourceFileTemplate = new Template(ctx.config.source_filename_format);

  for (let i = 0; i < mcVersionEntries.length; i++) {
    const mcVersionEntry = mcVersionEntries[i];

    try {
      const primaryFile = await readAsFile(buildJarPath(ctx.config.project_dir, primaryFileTemplate, ctx.input.version, mcVersionEntry.version));
      const sourceFile = await readAsFile(buildJarPath(ctx.config.project_dir, sourceFileTemplate, ctx.input.version, mcVersionEntry.version));

      await publishFn(ctx, mcVersionEntry, {
        primary: primaryFile,
        source: sourceFile,
      });
      result.success++;

      const isLast = i + 1 === total;
      ee.emit("progress", {
        platform,
        current: i + 1,
        total,
        status: isLast ? "completed" : "running",
        errors: result.errors,
      } satisfies ProgressEvent);
    } catch (err) {
      result.fail++;
      const msg = `${mcVersionEntry.version}: ${errorMessage(err)}`;
      result.errors.push(msg);

      ee.emit("progress", {
        platform,
        current: i,
        total,
        status: "failed",
        errors: result.errors,
      } satisfies ProgressEvent);

      // Cancel remaining for this platform only
      break;
    }
  }

  return result;
}

// ── Update orchestrator ────────────────────────────────

async function runPlatformUpdate(
  platform: typeof platforms[number],
  mcVersions: UpdateInput["mcVersions"][keyof UpdateInput["mcVersions"]],
  ctx: PlatformContext<UpdateInput>,
): Promise<PlatformResult> {
  const result: PlatformResult = { success: 0, fail: 0, errors: [] };
  const total = mcVersions.length;

  if (total === 0) {
    ee.emit("progress", {
      platform,
      current: 0,
      total: 0,
      status: "completed",
      errors: [],
    } satisfies ProgressEvent);
    return result;
  }

  ee.emit("progress", {
    platform,
    current: 0,
    total,
    status: "running",
    errors: [],
  } satisfies ProgressEvent);

  const adaptor = platformAdaptors[platform];

  // 准备阶段（范围计算 + 已有版本列表拉取），异常处理同 runPlatform
  let mcVersionEntries: McVersionEntry[];
  let existingReleases: ExistingRelease[];
  try {
    mcVersionEntries = await computeSelectedEntries(
      platform,
      mcVersions.map((v) => v.mc_version),
      ctx,
    );
    existingReleases = await adaptor.listExisting(ctx.config);
  } catch (err) {
    failPlatformPreparation(platform, total, result, err, "update");
    return result;
  }

  for (let i = 0; i < mcVersionEntries.length; i++) {
    const mcVersionEntry = mcVersionEntries[i];

    try {
      // 服务端按模板重新匹配已有版本，不信任前端传入的任何 ID
      const key = adaptor.matchKey(ctx.config, ctx.input.version, mcVersionEntry.version);
      const existing = existingReleases.find((e) => e.matchKey === key);
      if (!existing) {
        throw new Error(`平台上未找到版本 "${key}"，请改用发布流程`);
      }

      await adaptor.update(ctx, mcVersionEntry, existing);
      result.success++;

      const isLast = i + 1 === total;
      ee.emit("progress", {
        platform,
        current: i + 1,
        total,
        status: isLast ? "completed" : "running",
        errors: result.errors,
      } satisfies ProgressEvent);
    } catch (err) {
      result.fail++;
      const msg = `${mcVersionEntry.version}: ${errorMessage(err)}`;
      result.errors.push(msg);

      ee.emit("progress", {
        platform,
        current: i,
        total,
        status: "failed",
        errors: result.errors,
      } satisfies ProgressEvent);

      // Cancel remaining for this platform only
      break;
    }
  }

  return result;
}

// ── Router ─────────────────────────────────────────────

export const appRouter = t.router({
  publish: t.procedure
    .input(PublishInputSchema)
    .mutation(async ({ input }): Promise<PublishResult> => {
      const config = await getConfig(input.configFile);

      const ctx: PlatformContext = { input, config };

      const results = await Promise.all(platforms.map(async (platform) => {
        try {
          const result = await runPlatform(platform, input.mcVersions[platform], ctx);
          return {platform, result};
        } catch (err) {
          console.error(`[publish] ${platform} 执行异常:`, err);
          return {
            platform,
            result: { success: 0, fail: 0, errors: [errorMessage(err)] }
          }
        }
      }));

      return PublishResultSchema.parse(Object.fromEntries(results.map(result => [result.platform, result.result])));
    }),

  update: t.procedure
    .input(UpdateInputSchema)
    .mutation(async ({ input }): Promise<PublishResult> => {
      const config = await getConfig(input.configFile);

      const ctx: PlatformContext<UpdateInput> = { input, config };

      const results = await Promise.all(platforms.map(async (platform) => {
        try {
          const result = await runPlatformUpdate(platform, input.mcVersions[platform], ctx);
          return {platform, result};
        } catch (err) {
          console.error(`[update] ${platform} 执行异常:`, err);
          return {
            platform,
            result: { success: 0, fail: 0, errors: [errorMessage(err)] }
          }
        }
      }));

      return PublishResultSchema.parse(Object.fromEntries(results.map(result => [result.platform, result.result])));
    }),

  progress: t.procedure.subscription(async function* (opts) {
    for await (const [data] of on(ee, "progress", {
      signal: opts.signal,
    })) {
      const parsed = ProgressEventSchema.safeParse(data);
      if (!parsed.success) {
        // 坏事件不应中断订阅（客户端没有重连机制），跳过并记录
        console.error("[publish] invalid progress event:", parsed.error);
        continue;
      }
      yield parsed.data;
    }
  }),
});

export type AppRouter = typeof appRouter;