import fs from "node:fs/promises";
import path from "node:path";
import type { ScaffoldRecipe } from "./scaffold-recipes.js";
import type { StructuralRequest } from "./structural-plan.js";
import { parseQx, walkSyntax } from "./source.js";
import { addImplementation } from "./implementation-edit.js";
import { formatQuixosLock } from "../resource-lock/index.js";
import { javascriptTarget } from "../execution-world/native-backends.js";
const json = (value: unknown) => JSON.stringify(value, null, 2) + "\n";
const q = (value: string) => JSON.stringify(value);
const nixString = (value: string) => q(value).replaceAll("${", "\\${");
export async function isExecutionScaffold(root: string, prefix: string): Promise<boolean> {
  try {
    return JSON.parse(await fs.readFile(path.join(root, prefix, "quixos.check.json"), "utf8")).backend === "execution";
  } catch (error) {
    if ((error as NodeJS.ErrnoException).code === "ENOENT") return false;
    throw error;
  }
}
/** Insert ordinary authored code; declarations remain the only export inventory. */
export async function executionScaffold(
  root: string,
  command: string,
  spec: ScaffoldRecipe,
  prefix: string,
  nixSource: (source: NonNullable<ScaffoldRecipe["tools"]>["helpers"]) => string,
): Promise<StructuralRequest> {
  if (!spec.name || !/^[A-Za-z_][A-Za-z0-9_]*$/.test(spec.name) || !spec.id)
    throw new Error("Execution scaffold requires a simple name and an ID");
  if (spec.initialFiles && command !== "package") throw new Error("Initial files are only for new packages");
  const files: StructuralRequest["files"] = [];
  const create = (file: string, content: string) => files.push({ file: prefix + file, create: content });
  if (command === "package") {
    if (!spec.tools || !spec.revision) throw new Error("Execution package requires exact tool sources and a revision");
    create(
      "package.qx",
      `symbol JavaScript id ${q(javascriptTarget)};\npackage ${spec.name} id ${q(spec.id)} revision ${q(spec.revision)} {\n}\n`,
    );
    create(
      "quixos.lock",
      formatQuixosLock({ formatVersion: 1, quixos: { resolver: "git", ...spec.tools.quixos }, resources: [] }),
    );
    create("quixos.check.json", json({ backend: "execution" }));
    create("components.nix", "{\n}\n");
    create(
      "package.json",
      json({
        name: `@quixos/${spec.name.toLowerCase()}`,
        private: true,
        type: "module",
        packageManager: "yarn@4.18.0",
        scripts: { typecheck: "qx-workspace check" },
      }),
    );
    create(
      ".gitignore",
      "node_modules/\ndist/\nsrc/gen/\n.quixos/\nresult\n.yarn/cache/\n.yarn/install-state.gz\n.yarn/unplugged/\n",
    );
    create(
      ".yarnrc.yml",
      'enableScripts: true\n\ngenerateDefaultNix: false\n\nindividualNixPackaging: true\n\nnodeLinker: node-modules\n\nsupportedArchitectures:\n  os:\n    - current\n    - linux\n  cpu:\n    - current\n    - x64\n    - arm64\n  libc:\n    - current\n    - glibc\n\nplugins:\n  - checksum: 271de9a785321a37c564b8e2a6b5cd689850b20572d5fee8ec0a6b8e7a5d4cfb59e533524af2b4a537e00da12828abd062eaec6978556e3dd9149a020db2591b\n    path: .yarn/plugins/yarn-plugin-nixify.cjs\n    spec: "https://gitea-external.egads.tutti.syntaxblitz.net/quixos/yarn-plugin-nixify-patched/raw/commit/4528fdd20b30d869262443b3f044549810e75fb8/dist/yarn-plugin-nixify.js"\n',
    );
    for (const lane of ["browser", "server", "remote"])
      create(
        `src/${lane}.ts`,
        `import { createRegistry } from "./gen/${lane === "remote" ? "remote" : "qx"}.js";\nexport const registry = createRegistry({});\n`,
      );
    create(
      "flake.nix",
      `{
  inputs.protocol.url = ${nixString(nixSource(spec.tools.protocol))};
  inputs.nixpkgs.follows = "protocol/nixpkgs";
  inputs.flake-utils.follows = "protocol/flake-utils";
  inputs.helpers = { url = ${nixString(nixSource(spec.tools.helpers))}; flake = false; };
  outputs = { nixpkgs, flake-utils, helpers, ... }:
    flake-utils.lib.eachDefaultSystem (system: let
      pkgs = import nixpkgs { inherit system; };
      camino = import (helpers + "/quixos-package-helpers.nix");
    in {
      devShells.default = (import (helpers + "/quixos-package-helpers.nix")).mkCaminoYarnShell { inherit pkgs; };
      quixosPackages.checkedArtifacts = context:
let
  pkgs = camino.packageSet { inherit nixpkgs system context; };
  contract = builtins.fromJSON (builtins.readFile context.buildContract);
  package = contract.definition.package;
  portable = builtins.filter (entry: entry.execution.kind != "remote") package.exports;
  remote = builtins.filter (entry: entry.execution.kind == "remote") package.exports;
  modules = import ./components.nix;
  dependencies = if builtins.pathExists ./yarn-project.nix
    then camino.mkCaminoYarnDependencies { inherit pkgs; src = ./.; } else null;
in camino.assembleCaminoPackage {
  inherit pkgs context;
  artifacts =
    pkgs.lib.optional (portable != []) (camino.mkCaminoTypeScriptPackage {
      inherit pkgs context dependencies; src = ./.;
      entry = "src/server.ts"; entries.browser = "src/browser.ts";
      targets = pkgs.lib.unique (map (target: if target == "target:org.quixos.execution.javascript@1" then "browser" else if target == "server" then "server" else throw "Unsupported TypeScript backend target") (pkgs.lib.concatMap (entry: entry.execution.targets) portable));
    }) ++ pkgs.lib.optional (remote != []) (camino.mkCaminoTypeScriptService {
      inherit pkgs context dependencies; src = ./.; entry = "src/remote.ts";
    }) ++ pkgs.lib.optional (modules != {}) (camino.mkCaminoReactPackage {
      inherit pkgs context dependencies modules; src = ./.;
    });
};
    });
}
`,
    );
    create(
      "README.md",
      `# ${spec.name}\n\nThis execution package exports checked browser/server modules and a process service.\nUse scaffold function with an explicit execution contract to add a typed handler.\nSnapshot/transaction targets choose browser.ts and/or server.ts; remote handlers\nuse remote.ts. Shared helpers are ordinary imports. Generated bindings are build\noutputs, not authored source. The Nix composition supplies the canonical package contract\nand explicit runtime dependencies to checkedArtifacts.\n\nRun qx-workspace check from this package to build it independently, or from a\nworkspace to also check installed bindings. Activate the resulting report separately through the workspace\nhost. A source-only structural check is not runtime qualification.\n`,
    );
  } else if (command === "function") {
    if (!spec.declaration)
      throw new Error("Execution functions require a declaration with explicit execution effect and targets");
    const wrapped = `package Scaffold id "scaffold" revision "scaffold@1" { ${spec.declaration} }`;
    const parsed = parseQx(wrapped);
    const pkg = parsed.root.children.find((node) => node.kind === "packageResourceDecl");
    const exports = [...walkSyntax(parsed.root)].filter((node) =>
      ["packageFunctionExport", "packageOperationExport"].includes(node.kind),
    );
    const declaration = exports[0];
    if (
      parsed.diagnostics.length ||
      exports.length !== 1 ||
      !declaration ||
      parsed.root.children.length !== 1 ||
      pkg?.children.filter((node) => node.kind === "packageExport").length !== 1 ||
      pkg?.children.some((node) => !["identifier", "stringLiteral", "packageExport"].includes(node.kind))
    )
      throw new Error("Expected one function or operation export with an execution contract");
    const text = (node: { start: number; end: number }) => wrapped.slice(node.start, node.end);
    const name = declaration.children.find((node) => node.kind === "identifier");
    const id = declaration.children.find((node) => node.kind === "stringLiteral");
    const execution = declaration.children.find((node) => node.kind === "executionClause");
    if (!name || text(name) !== spec.name || !id || JSON.parse(text(id)) !== spec.id || !execution)
      throw new Error("Declaration name/ID must match; an explicit execution contract is required");
    const tokens = parsed.tokens
      .filter((token) => !token.trivia && token.start >= execution.start && token.end <= execution.end)
      .map((token) => token.text);
    const remote = tokens[1] === "remote";
    const declaredTargets = remote
      ? ["remote"]
      : [...walkSyntax(execution)].filter((node) => node.kind === "identifier").map(text);
    const targets = declaredTargets.length ? declaredTargets : ["server"];
    if (
      !targets.length ||
      new Set(targets).size !== targets.length ||
      targets.some((target) => !(remote ? ["remote"] : ["JavaScript", "server"]).includes(target))
    )
      throw new Error("This TypeScript scaffold supports the JavaScript target, server, and remote service handlers");
    const authored = await fs.readFile(path.join(root, prefix, "package.qx"), "utf8");
    const syntax = parseQx(authored);
    const packageNode = syntax.root.children.find((node) => node.kind === "packageResourceDecl");
    if (syntax.diagnostics.length || !packageNode) throw new Error("Fix package.qx before adding a handler");
    for (const node of [...walkSyntax(packageNode)].filter((node) =>
      ["packageFunctionExport", "packageOperationExport", "packageConstructorExport"].includes(node.kind),
    )) {
      const identifier = node.children.find((child) => child.kind === "identifier");
      const literal = node.children.find((child) => child.kind === "stringLiteral");
      if (
        (identifier && authored.slice(identifier.start, identifier.end) === spec.name) ||
        (literal && JSON.parse(authored.slice(literal.start, literal.end)) === spec.id)
      )
        throw new Error("New export requires a unique name and ID");
    }
    const packageID = packageNode.children.find((node) => node.kind === "stringLiteral")!;
    files.push({
      file: prefix + "package.qx",
      edits: [
        {
          operation: "append",
          parent: { kind: "packageResourceDecl", id: JSON.parse(authored.slice(packageID.start, packageID.end)) },
          source: spec.declaration,
        },
      ],
    });
    create(
      `src/impl/${spec.name}.ts`,
      `import type { ${remote ? "Remote" : "Portable"}Implementation } from "../gen/${remote ? "remote" : "qx"}.js";\nexport const handler: ${remote ? "Remote" : "Portable"}Implementation[${q(spec.name)}] = async (_context) => { throw new Error(${q("Implement " + spec.name)}); };\n`,
    );
    for (const target of targets) {
      const file = prefix + `src/${target === "JavaScript" ? "browser" : target}.ts`;
      const before = await fs.readFile(path.join(root, file), "utf8");
      files.push({
        file,
        expected: before,
        replace: addImplementation(before, "createRegistry", spec.name, `./impl/${spec.name}.js`),
      });
    }
  } else
    throw new Error("Execution packages use ordinary factory transactions; migration scaffolding is not supported");
  if (spec.initialFiles) {
    for (const [file, content] of Object.entries(spec.initialFiles)) {
      if (
        typeof content !== "string" ||
        !/^(?:package\.qx|(?:package|components|flake|yarn-project)\.nix|package\.json|yarn\.lock|\.yarnrc\.yml|\.gitignore|\.yarn\/plugins\/[A-Za-z0-9_.-]+\.cjs|quixos\.controllers\.json|README\.md|(?:src|queries)\/(?:[A-Za-z0-9_-]+\/)*[A-Za-z0-9_.-]+)$/.test(
          file,
        ) ||
        file.split("/").some((part) => part === ".." || part === "." || part === "gen")
      )
        throw new Error("Not an initial authored execution file: " + file);
      const previous = files.findIndex((entry) => entry.file === prefix + file);
      if (previous >= 0) files.splice(previous, 1);
      create(file, content);
    }
  }
  return { kind: "package", source: spec.source, resourceRoot: spec.directory, validation: "syntax", files };
}