import { compileInspectionTemplates, type InspectionTemplate } from "./inspection.js";
import path from "node:path";
import { loadCheckedArtifactWorld } from "./receipts.js";
import { contentArtifactUrl, loadArtifactWorld, type LoadedArtifactWorld } from "./files.js";
import { selectArtifactImplementation, type ArtifactImplementation, type ComponentArtifact } from "./artifacts.js";
import { ExecutionPlanError, hexDigest, type ExecutionPlan } from "./plan.js";
import {
  publicOperationContract,
  publicQueryContract,
  type PublicOperationContract,
  type PublicQueryContract,
} from "./client-contracts.js";
import { resultInterfaces } from "./projections.js";

/** Activation is assigned by graph authority, never by a package artifact. */
export interface ActiveExecutionIdentity {
  readonly workspace: string;
  readonly world: string;
  readonly plan: string;
  readonly epoch: string;
}
/** Host-owned execution selection. The lifecycle manager fills its checked inputs. */
export interface ExecutionGroupIdentity {
  readonly logicalId: string;
  readonly executionDigest: string;
}
export interface ClientContractCatalog {
  readonly inspections: readonly InspectionTemplate[];
  readonly resultInterfaces: Readonly<Record<string, readonly string[]>>;
  readonly operations: readonly PublicOperationContract[];
  readonly queries: readonly PublicQueryContract[];
  readonly components: readonly InstalledComponent[];
  readonly presentations: readonly { id: string; subject: string; packageRevision: string; component: string }[];
  readonly moduleBindings: readonly {
    atom: string;
    interface: string;
    member: string;
    packageRevision: string;
    id: string;
  }[];
}
/** Explicit projection prevents accidental spreading of filesystem roots or private bindings. */
export function clientContractCatalog(
  plan: ExecutionPlan,
  installation: ExecutionInstallation,
  requestedPackages: readonly string[],
): ClientContractCatalog {
  if (installation.plan !== plan.digest || hexDigest(plan.definition) !== plan.digest)
    throw new ExecutionPlanError(
      "CATALOG_PLAN_MISMATCH",
      plan.digest,
      "Installation and public catalog must use the same checked plan",
    );
  const packages = requestedPackages.map((revision) => {
    const pkg = plan.definition.workspace.packageImports.find((p) => p.revisionId === revision);
    if (!pkg)
      throw new ExecutionPlanError("UNINSTALLED_PACKAGE", revision, "Requested catalog package is not installed");
    return pkg;
  });
  // Interface metadata contains no authority or private implementation configuration.
  // A later admission optimization can narrow this set without changing operation identities.
  const operations = plan.definition.workspace.interfaceImports
    .filter((i) => !i.template)
    .flatMap((iface) =>
      iface.members.flatMap((member) =>
        member.operations
          .filter((o) => o.mode === "call")
          .map((operation) => publicOperationContract(iface, operation)),
      ),
    );
  const inspection = compileInspectionTemplates(plan);
  return {
    inspections: inspection.templates,
    resultInterfaces: Object.fromEntries(
      plan.definition.operations.map((operation) => [operation.key, resultInterfaces(plan, operation.key)]),
    ),
    operations,
    queries: [
      ...inspection.contracts,
      ...packages.flatMap((pkg) => (pkg.checkedQueries ?? []).map((q) => publicQueryContract(pkg, q.declaration.id))),
    ],
    components: installation.components.filter((c) => requestedPackages.includes(c.packageRevision)),
    moduleBindings: plan.definition.workspace.conformances.flatMap((c) =>
      (c.moduleBindings ?? [])
        .filter((b) => requestedPackages.includes(b.packageRevisionId))
        .map((b) => ({
          atom: c.atomId,
          interface: c.interfaceRevisionId,
          member: b.memberId,
          packageRevision: b.packageRevisionId,
          id: b.moduleId,
        })),
    ),
    presentations: (plan.definition.presentations ?? [])
      .filter((p) => requestedPackages.includes(p.packageRevisionId))
      .map((p) => ({ id: p.id, subject: p.subject, packageRevision: p.packageRevisionId, component: p.componentId })),
  };
}

export interface PackageInstallationSelection {
  readonly browser?: { readonly id?: string };
  readonly service?: { readonly id?: string };
  /** Including a module is optional; executing it still requires host trust policy. */
  readonly module?: { readonly id?: string };
}
export interface ExecutionInstallation {
  readonly codec: "camino-execution-installation-v1";
  readonly plan: string;
  readonly world: string;
  readonly packages: readonly {
    readonly revision: string;
    readonly root: string;
    readonly service?: ArtifactImplementation;
    readonly module?: ArtifactImplementation;
    readonly browserImplementation?: ArtifactImplementation;
    readonly browserURL?: string;
    readonly browserRegistry?: string;
  }[];
  readonly routes: Readonly<Record<string, { readonly path: string; readonly mediaType: string }>>;
  readonly coreURL?: string;
  readonly engineURL?: string;
  readonly components: readonly InstalledComponent[];
}
/** Safe to expose in a presentation catalog: no source paths, state slots, or host configuration. */
export interface InstalledComponent {
  readonly role: {
    readonly interface: string;
    readonly member: string;
    readonly subject: string;
    readonly contract: string;
    readonly typeArguments?: readonly unknown[];
    readonly requiredInterfaces?: readonly string[];
  };
  readonly packageRevision: string;
  readonly id: string;
  readonly subject: string;
  readonly url: string;
  readonly exportName: string;
  readonly styles: readonly string[];
  readonly compatibility: ComponentArtifact["compatibility"];
  /** Owned and interpreted by the React artifact consumer. */
  readonly preparation?: unknown;
  readonly sharedModules: Readonly<Record<keyof ComponentArtifact["sharedModules"], string>>;
}
/** Build-time validation uses the compiler selected by the Nix derivation. */
export async function checkExecutionInstallation(
  plan: ExecutionPlan,
  roots: Readonly<Record<string, string>>,
  generator: string,
  selections: Readonly<Record<string, PackageInstallationSelection>> = {},
): Promise<ExecutionInstallation> {
  const loaded = await loadCheckedArtifactWorld(plan, roots, generator);
  return assembleExecutionInstallation(plan, roots, loaded, selections);
}
/** Load immutable artifacts without regenerating bindings with the host compiler.
 * Format, coverage, content and runtime ABI checks still apply. This grants no
 * authority to activate a world or run optional modules in process. */
export async function loadExecutionInstallation(
  plan: ExecutionPlan,
  roots: Readonly<Record<string, string>>,
  selections: Readonly<Record<string, PackageInstallationSelection>> = {},
): Promise<ExecutionInstallation> {
  return assembleExecutionInstallation(plan, roots, await loadArtifactWorld(plan, roots), selections);
}
function assembleExecutionInstallation(
  plan: ExecutionPlan,
  roots: Readonly<Record<string, string>>,
  loaded: LoadedArtifactWorld,
  selections: Readonly<Record<string, PackageInstallationSelection>>,
): ExecutionInstallation {
  const fail = (where: string, message: string): never => {
    throw new ExecutionPlanError("INSTALLATION_INVALID", where, message);
  };
  for (const revision of Object.keys(selections))
    if (!loaded.manifests.some((manifest) => manifest.packageRevisionId === revision))
      fail(revision, "Selection names a package outside this checked world");
  const routes: Record<string, { path: string; mediaType: string }> = Object.create(null);
  const packages: ExecutionInstallation["packages"][number][] = [];
  const components: InstalledComponent[] = [];
  const sharedComponentModules = new Map<string, string>();
  let coreURL: string | undefined, engineURL: string | undefined;
  for (const manifest of loaded.manifests) {
    const revision = manifest.packageRevisionId;
    const root = roots[revision]!;
    const selection = selections[revision] ?? {};
    const exports = plan.definition.packages.find((pkg) => pkg.revision === revision)!.exports;
    const service =
      exports.length || selection.service
        ? selectArtifactImplementation(manifest, {
            ...selection.service,
            target: "server",
            compatibility: "quixos-service-v1",
            exports: exports.map((entry) => entry.id),
          })
        : undefined;
    for (const component of manifest.components ?? []) {
      const sharedModules = Object.fromEntries(
        Object.entries(component.sharedModules).map(([name, filePath]) => {
          const file = component.files.find((file) => file.path === filePath)!;
          const url = contentArtifactUrl(file),
            previous = sharedComponentModules.get(name);
          if (previous && previous !== url) fail(component.id, `Components disagree on shared module ${name}`);
          sharedComponentModules.set(name, url);
          return [name, url];
        }),
      ) as InstalledComponent["sharedModules"];
      for (const file of component.files) {
        const url = contentArtifactUrl(file);
        if (routes[url] && routes[url].mediaType !== file.mediaType) fail(url, "Conflicting artifact media types");
        routes[url] ??= { path: path.join(root, file.path), mediaType: file.mediaType };
      }
      components.push({
        ...(() => {
          const pkg = plan.definition.workspace.packageImports.find((entry) => entry.revisionId === revision);
          const artifact = pkg?.buildArtifacts?.["org.quixos.react.preparation/1"] as
            | { modules: { module: string }[] }
            | undefined;
          const preparation = artifact?.modules.find((entry) => entry.module === component.id);
          return preparation ? { preparation } : {};
        })(),
        role: (() => {
          const module = plan.definition.packages
            .find((p) => p.revision === revision)!
            .modules!.find((m) => m.id === component.id)!;
          return {
            interface: module.interfaceRevisionId,
            member: module.memberId,
            subject: component.subject,
            contract: module.contract,
            ...(module.typeArguments ? { typeArguments: module.typeArguments } : {}),
            ...(module.requiredInterfaces ? { requiredInterfaces: module.requiredInterfaces } : {}),
          };
        })(),
        packageRevision: revision,
        id: component.id,
        subject: component.subject,
        compatibility: component.compatibility,
        exportName: component.exportName,
        styles: component.files.filter((file) => file.mediaType === "text/css").map(contentArtifactUrl),
        sharedModules,
        url: contentArtifactUrl(component.files.find((file) => file.path === component.path)!),
      });
    }
    const module = selection.module
      ? selectArtifactImplementation(manifest, {
          ...selection.module,
          target: "server",
          compatibility: "quixos-js-module-v1",
          exports: exports.map((entry) => entry.id),
        })
      : undefined;
    const browserExports = exports.filter(
      (entry) =>
        entry.execution.kind !== "remote" &&
        entry.execution.targets.includes("target:org.quixos.execution.javascript@1"),
    );
    if (!browserExports.length) {
      if (selection.browser) fail(revision, "Package has no browser exports to select");
      packages.push({ revision, root, ...(service ? { service } : {}), ...(module ? { module } : {}) });
      continue;
    }
    const browser = selectArtifactImplementation(manifest, {
      ...selection.browser,
      target: "target:org.quixos.execution.javascript@1",
      compatibility: "quixos-js-module-v1",
      exports: browserExports.map((entry) => entry.id),
    });
    const entry = browser.files.find((file) => file.path === browser.path)!;
    const shared = (name: string) => {
      const files = browser.files.filter((file) => file.path.endsWith("/" + name));
      if (files.length !== 1) fail(revision, "Expected one shared " + name);
      return contentArtifactUrl(files[0]!);
    };
    const core = shared("core.mjs"),
      engine = shared("engine.mjs");
    if ((coreURL && coreURL !== core) || (engineURL && engineURL !== engine))
      fail(revision, "Browser packages disagree on the shared runtime identity");
    coreURL = core;
    engineURL = engine;
    for (const file of browser.files) {
      const url = contentArtifactUrl(file);
      if (routes[url] && routes[url].mediaType !== file.mediaType) fail(url, "Conflicting artifact media types");
      routes[url] ??= { path: path.join(root, file.path), mediaType: file.mediaType };
    }
    packages.push({
      revision,
      root,
      ...(service ? { service } : {}),
      ...(module ? { module } : {}),
      browserImplementation: browser,
      browserURL: contentArtifactUrl(entry),
      browserRegistry: browser.registryExport,
    });
  }
  return {
    codec: "camino-execution-installation-v1",
    plan: plan.digest,
    world: loaded.digest,
    packages,
    components,
    routes,
    ...(coreURL ? { coreURL, engineURL } : {}),
  };
}