import { readdir, rm, writeFile } from "node:fs/promises";
import { join, relative, sep } from "node:path";
import { fileURLToPath } from "node:url";

import { APP } from "../src/shared/app";
import { validateVersion } from "./bump-version-logic";

const projectRoot = fileURLToPath(new URL("..", import.meta.url));
const distWebDir = join(projectRoot, "dist/web");
const buildDir = join(projectRoot, ".build");
const executablePath = join(projectRoot, `dist/${APP.name}`);
const packageJsonPath = join(projectRoot, "package.json");

async function build() {
  try {
    await viteBuild();
    await codeGeneration();
    await bunCompile();
    await cleanup();
    console.log(`Built executable: ${executablePath}`);
  } catch (error) {
    await cleanup();
    console.error("Build failed:", error);
    process.exit(1);
  }
}

async function bunCompile() {
  console.log("Step 4/4: Bun compile...");
  await rm(executablePath, { force: true });

  const target = process.env["BUN_TARGET"] ?? process.env["BUILD_TARGET"];
  const result = await Bun.build({
    compile: target
      ? {
          autoloadBunfig: true,
          autoloadDotenv: true,
          outfile: executablePath,
          target: target as Bun.Build.CompileTarget,
        }
      : {
          autoloadBunfig: true,
          autoloadDotenv: true,
          outfile: executablePath,
        },
    entrypoints: [join(buildDir, "server-entry.ts")],
    minify: true,
    sourcemap: "linked",
  });

  if (!result.success) {
    console.error("Bun compile failed:", result.logs);
    await cleanup();
    process.exit(1);
  }
}

async function cleanup() {
  await rm(buildDir, { force: true, recursive: true });
}

async function codeGeneration() {
  console.log("Step 2/4: Code generation...");
  await rm(buildDir, { force: true, recursive: true });
  await Bun.write(join(buildDir, ".gitkeep"), "");

  const packageJson = (await Bun.file(packageJsonPath).json()) as { version: string };
  const version = packageJson.version;
  if (typeof version !== "string") {
    console.error("package.json does not have a valid version field");
    process.exit(1);
  }
  validateVersion(version);

  await generateMigrationsData();

  console.log("Step 3/4: Generating static assets...");
  const allFiles = await scanDir(distWebDir, "/");
  const importLines: string[] = [];
  const fileEntries: string[] = [];
  let indexHtmlVar = "";

  for (let i = 0; i < allFiles.length; i++) {
    const urlPath = allFiles[i]!;
    const varName = `f${i}`;
    const filePath = toImportSpecifier(buildDir, join(distWebDir, urlPath.slice(1)));
    importLines.push(`import ${varName} from "./${filePath}" with { type: "file" };`);

    if (urlPath === "/index.html") {
      indexHtmlVar = varName;
    } else {
      fileEntries.push(`  "${urlPath}": Bun.file(${varName}),`);
    }
  }

  if (!indexHtmlVar) {
    console.error("index.html not found in dist/web/");
    process.exit(1);
  }

  const staticAssetsTs = [
    `import type { StaticAssets } from "../src/server/static";`,
    "",
    ...importLines,
    "",
    `export const staticAssets: StaticAssets = {`,
    `  files: {`,
    ...fileEntries,
    `  },`,
    `  indexHtml: Bun.file(${indexHtmlVar}),`,
    `};`,
    "",
  ].join("\n");

  await writeFile(join(buildDir, "static-assets.ts"), staticAssetsTs);

  const serverEntryTs = [
    `import { bootstrap } from "../src/server/bootstrap";`,
    `import { parseRuntimeArgs } from "../src/server/config";`,
    `import { createConsoleFallback } from "../src/server/logger";`,
    `import { MIGRATIONS } from "./migrations-data";`,
    `import { staticAssets } from "./static-assets";`,
    "",
    `const APP_VERSION = "${version}" as const;`,
    "",
    `async function main() {`,
    `  const { configPath } = parseRuntimeArgs();`,
    `  await bootstrap({ configPath, migrations: MIGRATIONS, mode: "production", staticAssets, version: APP_VERSION });`,
    `}`,
    "",
    `void main().catch((error) => {`,
    `  createConsoleFallback().fatal(\`启动失败: \${error instanceof Error ? error.message : String(error)}\`);`,
    `  process.exit(1);`,
    `});`,
    "",
  ].join("\n");

  await writeFile(join(buildDir, "server-entry.ts"), serverEntryTs);
}

async function generateMigrationsData() {
  const { createHash } = await import("node:crypto");
  const { readdirSync, readFileSync } = await import("node:fs");
  const migrationsDir = join(projectRoot, "drizzle");

  let entries: string[];
  try {
    entries = readdirSync(migrationsDir)
      .filter((f) => f.endsWith(".sql"))
      .sort();
  } catch {
    entries = [];
  }

  const records = entries.map((filename) => {
    const sql = readFileSync(join(migrationsDir, filename), "utf-8");
    const id = filename.replace(/\.sql$/, "");
    const checksum = createHash("sha256").update(sql).digest("hex").slice(0, 16);
    return { checksum, id, sql: sql.trim() };
  });

  const lines = [
    `import type { MigrationRecord } from "../src/server/db/load-migrations";`,
    ``,
    `export const MIGRATIONS: MigrationRecord[] = [`,
    ...records.map(
      (r) =>
        `  { id: ${JSON.stringify(r.id)}, sql: ${JSON.stringify(r.sql)}, checksum: ${JSON.stringify(r.checksum)} },`,
    ),
    `];`,
    ``,
  ].join("\n");

  await writeFile(join(buildDir, "migrations-data.ts"), lines);
  console.log(`Embedded ${records.length} migration(s)`);
}

async function scanDir(dir: string, prefix: string): Promise<string[]> {
  const entries = await readdir(dir, { withFileTypes: true });
  const paths: string[] = [];
  for (const entry of entries) {
    const fullPath = join(dir, entry.name);
    const urlPath = `${prefix}${entry.name}`;
    if (entry.isDirectory()) {
      paths.push(...(await scanDir(fullPath, `${urlPath}/`)));
    } else {
      paths.push(urlPath);
    }
  }
  return paths;
}

function toImportSpecifier(fromDir: string, targetPath: string) {
  return relative(fromDir, targetPath).split(sep).join("/");
}

async function viteBuild() {
  console.log("Step 1/3: Vite build...");
  const proc = Bun.spawn(["bunx", "--bun", "vite", "build"], {
    cwd: projectRoot,
    stderr: "inherit",
    stdout: "inherit",
  });
  const exitCode = await proc.exited;
  if (exitCode !== 0) {
    console.error("Vite build failed");
    process.exit(1);
  }
}

await build();