import { compileKernelProgram } from "../execution-world/kernel.js";
import { hexDigest, type ExecutionPlan } from "../execution-world/plan.js";
import { resultInterfaces } from "../execution-world/projections.js";
import { portableValueSchema, tsType, PortableBindingError } from "./portable.js";
import type { QuerySelection } from "../query/types.js";
const conditional = (selections: readonly QuerySelection[]): boolean =>
  selections.some((selection) => selection.conditions.length > 0 || conditional(selection.selection));
/** Closed-world app descriptors. Handler bindings and application acquisition share the same public identities. */
export function generatePortableClientBindings(
  plan: ExecutionPlan,
  options: { target: string; runtimeModule?: string },
): string {
  if (hexDigest(plan.definition) !== plan.digest) throw new PortableBindingError("client", "Invalid plan digest");
  const executionPlan = (compileKernelProgram(plan) as { plan: string }).plan;
  const workspace = plan.definition.workspace,
    atoms = new Map<string, string[]>(),
    unavailable: { key: string; reason: string }[] = [];
  const seen = new Set<string>();
  for (const operation of plan.definition.operations) {
    if (operation.execution.kind === "remote" || !operation.availableTargets.includes(options.target)) {
      unavailable.push({ key: operation.key, reason: "OPERATION_NOT_PORTABLE" });
      continue;
    }
    let input: string, output: string;
    try {
      input = tsType(operation.input);
      output = tsType(operation.output);
    } catch (error) {
      if (!(error instanceof PortableBindingError)) throw error;
      unavailable.push({ key: operation.key, reason: "UNSUPPORTED_OPERATION_CODEC" });
      continue;
    }
    const atom = workspace.atoms.find((a) => a.id === operation.atomId)!;
    const iface = workspace.interfaceImports.find((i) => i.revisionId === operation.interfaceRevisionId)!;
    const member = iface.members.find((m) => m.operations.some((o) => o.id === operation.operationId))!;
    const facet = member.operations.find((o) => o.id === operation.operationId)!;
    const name = `${iface.displayName}.${member.displayName}.${facet.displayName}`;
    const alias = JSON.stringify([atom.displayName, name]);
    if (seen.has(alias)) throw new PortableBindingError(alias, "Ambiguous application descriptor alias");
    seen.add(alias);
    const roots = resultInterfaces(plan, operation.key);
    const descriptor = {
      key: operation.key,
      plan: executionPlan,
      effect: operation.execution.kind,
      input: portableValueSchema(operation.input),
      output: portableValueSchema(operation.output),
      resultInterfaces: roots,
    };
    const list = atoms.get(atom.displayName) ?? [];
    list.push(
      `${JSON.stringify(name)}: defineOperationDescriptor<${input}, ${output}, ${roots.map((r) => JSON.stringify(r)).join(" | ") || "never"}, ${JSON.stringify(operation.execution.kind)}>(${JSON.stringify(descriptor)})`,
    );
    atoms.set(atom.displayName, list);
  }
  const queries = new Map<string, string[]>();
  const views = new Map<string, string[]>();
  const serverProjections = new Map<string, string[]>();
  const results = new Map<string, string[]>();
  for (const query of plan.definition.queries) {
    const declaration = query.query.checked.declaration;
    const pkg = workspace.packageImports.find((p) => p.revisionId === query.query.packageRevisionId)!;
    const alias = JSON.stringify([pkg.displayName, declaration.displayName]);
    if (seen.has(`query:${alias}`)) throw new PortableBindingError(alias, "Ambiguous query alias");
    seen.add(`query:${alias}`);
    const addResult = () => {
      if (conditional(query.query.checked.selection)) {
        unavailable.push({ key: query.id, reason: "CONDITIONAL_RESULT_DECODER_UNSUPPORTED" });
        return;
      }
      const decoders = results.get(pkg.displayName) ?? [];
      decoders.push(
        `${JSON.stringify(declaration.displayName)}: (data: Json): ${tsType(query.query.checked.output)} => decodeArgument(${JSON.stringify(portableValueSchema(query.query.checked.output))}, { codec: "camino-value-v1", usage: "argument", value: data }, { workspace: workspaceId(${JSON.stringify(workspace.workspaceId)}), limits: { bytes: ${declaration.budgets.resultBytes + 128}, nodes: 100000, depth: 64 } }) as ${tsType(query.query.checked.output)}`,
      );
      results.set(pkg.displayName, decoders);
    };
    if (!declaration.placement) {
      const operations = query.operations.map(
        (key) => plan.definition.operations.find((operation) => operation.key === key)!,
      );
      if (
        operations.some(
          (operation) => operation.execution.kind !== "snapshot" || !operation.execution.targets.includes("server"),
        )
      ) {
        unavailable.push({ key: query.id, reason: "QUERY_NOT_SNAPSHOT_PROJECTION" });
        continue;
      }
      const list = serverProjections.get(pkg.displayName) ?? [];
      list.push(
        JSON.stringify(declaration.displayName) +
          ": " +
          JSON.stringify({
            kind: "server-projection",
            id: query.id,
            plan: executionPlan,
            root: declaration.root.interface,
            rootKind: declaration.root.kind,
          }) +
          " as const satisfies ServerProjection<" +
          JSON.stringify(declaration.root.interface) +
          ", " +
          JSON.stringify(declaration.root.kind) +
          ">",
      );
      serverProjections.set(pkg.displayName, list);
      addResult();
      continue;
    }
    if (declaration.placement.kind === "local") {
      const list = views.get(pkg.displayName) ?? [];
      list.push(
        `${JSON.stringify(declaration.displayName)}: ${JSON.stringify({ id: query.id, plan: executionPlan, source: JSON.stringify([query.query.packageRevisionId, declaration.placement.sourceQueryId]) })} as const satisfies LocalQueryDescriptor`,
      );
      views.set(pkg.displayName, list);
      addResult();
      continue;
    }
    const list = queries.get(pkg.displayName) ?? [];
    list.push(
      `${JSON.stringify(declaration.displayName)}: { id: ${JSON.stringify(query.id)}, plan: ${JSON.stringify(executionPlan)}, root: ${JSON.stringify(declaration.root.interface)}, rootKind: ${JSON.stringify(declaration.root.kind)} } as const satisfies ReplicaProjection<${JSON.stringify(declaration.root.interface)}, ${JSON.stringify(declaration.root.kind)}>`,
    );
    queries.set(pkg.displayName, list);
  }
  const groups = (entries: Map<string, string[]>) =>
    [...entries].map(([name, values]) => `${JSON.stringify(name)}: {${values.join(",\n")}}`).join(",\n");
  return `// Generated application descriptors. Regenerate; do not edit.\nimport { defineOperationDescriptor, decodeArgument, workspaceId, type Json, type PreparedChange, type ManagedReference, type ReplicaProjection, type ServerProjection, type LocalQueryDescriptor } from ${JSON.stringify(options.runtimeModule ?? "@quixos/camino-replica-core")};\nexport const planDigest = ${JSON.stringify(executionPlan)};\nexport const operations = {${groups(atoms)}} as const;\nexport const queries = {${groups(queries)}} as const;\nexport const views = {${groups(views)}} as const;\nexport const serverProjections = {${groups(serverProjections)}} as const;\nexport const results = {${groups(results)}} as const;\nexport const unavailable = ${JSON.stringify(unavailable)} as const;\n`;
}