import type { WorkspaceRevision } from "./types.js";
import type { CapabilityValidationIssue } from "./validation.js";
import { moduleContract } from "./modules.js";

/** Presentation metadata has no graph authority and cannot name arbitrary module URLs. */
export function validatePresentations(workspace: WorkspaceRevision): CapabilityValidationIssue[] {
  const issues: CapabilityValidationIssue[] = [];
  const fail = (path: string, message: string) => issues.push({ code: "invalid-presentation", path, message });
  const interfaces = new Map(workspace.interfaceImports.map((entry) => [entry.revisionId, entry]));
  const packages = new Map(workspace.packageImports.map((entry) => [entry.revisionId, entry]));
  const text = (value: string, path: string) => {
    if (!value.trim()) fail(path, "Presentation identities and names must be nonempty");
  };
  const subject = (id: string, path: string) => {
    const contract = interfaces.get(id as WorkspaceRevision["interfaceImports"][number]["revisionId"]);
    if (!contract || contract.template) fail(path, `Expected an imported closed subject interface: ${id}`);
  };
  for (const [index, pkg] of workspace.packageImports.entries()) {
    for (const [alias, id] of Object.entries(pkg.clientInterfaces ?? {})) {
      text(alias, `packageImports[${index}].clientInterfaces`);
      subject(id, `packageImports[${index}].clientInterfaces.${alias}`);
    }
  }
  const ids = new Set<string>(),
    names = new Set<string>();
  for (const [index, presentation] of (workspace.presentations ?? []).entries()) {
    const path = `presentations[${index}]`;
    text(presentation.id, `${path}.id`);
    text(presentation.displayName, `${path}.displayName`);
    if (ids.has(presentation.id) || names.has(presentation.displayName))
      fail(path, "Duplicate presentation identity or name");
    ids.add(presentation.id);
    names.add(presentation.displayName);
    subject(presentation.subject, `${path}.subject`);
    const module = packages
      .get(presentation.packageRevisionId)
      ?.modules?.find((entry) => entry.id === presentation.componentId);
    if (module) {
      const contract = moduleContract(workspace.interfaceImports, module);
      if (contract?.contract !== "org.quixos.react.subject-only/1")
        fail(`${path}.componentId`, "Standalone presentation requires a subject-only module contract");
      if (contract?.subject?.kind !== "interface" || contract.subject.interfaceRevisionId !== presentation.subject)
        fail(`${path}.subject`, "Component requires its exact declared subject interface");
      continue;
    }
    fail(`${path}.componentId`, "Presentation names no installed package component");
  }
  return issues;
}