import { initTRPC } from "@trpc/server";
import EventEmitter, { on } from "node:events";
import { getConfig } from "./config";
import { errorMessage } from "@/lib/utils/error";
import {
  PublishInputSchema,
  type ProgressEvent,
  type PlatformResult,
  type PublishResult,
  platforms,
  type PlatformContext,
  type PlatformAdaptor,
} from "./publish.schemas";
import { publishModrinthVersion } from "./platforms/modrinth";
import { publishCurseForgeVersion } from "./platforms/curseforge";
import { computeVersionRanges } 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,
    getGameVersions: getModrinthMcVersions,
  },
  curseforge: {
    publish: publishCurseForgeVersion,
    getGameVersions: getCurseForgeMcVersions,
  },
};

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

const t = initTRPC.create();

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

const ee = new EventEmitter();

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

async function runPlatform(
  platform: typeof platforms[number],
  mcVersions: { mc_version: string }[],
  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;
  const getGameVersionsFn = platformAdaptors[platform].getGameVersions;

  const mcVersionEntries = computeVersionRanges(
    mcVersions.map(v => v.mc_version),
    await getGameVersionsFn(),
    ctx.input.cutoffMcVersion
  );

  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;
}

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

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

      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) {
          return {
            platform,
            result: { success: 0, fail: 0, errors: [errorMessage(err)] }
          }
        }
      }));

      return 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,
    })) {
      yield data as ProgressEvent;
    }
  }),
});

export type AppRouter = typeof appRouter;