import type { IOFormatMatrixFormat, IOFormatMatrixOperation } from "./io-format-capability-matrix";

export const IO_FORMAT_RUNTIME_RECEIPT_SCHEMA = 1 as const;
export const IO_FORMAT_RUNTIME_RECEIPT_TASK = "M12-05D" as const;
export const IO_FORMAT_RUNTIME_FORMATS = ["GLTF", "GLB", "OBJ", "STL", "PLY", "USD", "ALEMBIC"] as const;
export type IOFormatRuntimeFormat = typeof IO_FORMAT_RUNTIME_FORMATS[number];
export type IOFormatRuntimeOperation = IOFormatMatrixOperation;
export type IOFormatRuntimeStatus = "AVAILABLE" | "OPERATOR_UNREGISTERED";

export interface IOFormatRuntimeIdentityIR {
  blenderVersion: string;
  versionTuple: [number, number, number];
  buildHash: string;
  buildBranch: string;
  buildPlatform: string;
  buildType: string;
  buildDate: string;
  buildTime: string;
  buildCommitTimestamp: number;
  binarySha256: string;
  buildOptions: Record<string, boolean>;
}

export interface IOFormatRuntimeReceiptIR {
  format: IOFormatRuntimeFormat;
  family: string;
  operation: IOFormatRuntimeOperation;
  operator: string;
  registered: boolean;
  rnaIdentifier: string | null;
  buildOption: string | null;
  buildOptionEnabled: boolean | null;
  runtimeStatus: IOFormatRuntimeStatus;
  variants: string[];
  extensions: string[];
}

export interface IOFormatRuntimeReceiptSetIR {
  schemaVersion: typeof IO_FORMAT_RUNTIME_RECEIPT_SCHEMA;
  task: typeof IO_FORMAT_RUNTIME_RECEIPT_TASK;
  inventorySha256: string;
  runtime: IOFormatRuntimeIdentityIR;
  receipts: IOFormatRuntimeReceiptIR[];
}

export interface IOFormatRuntimeRouteQuery {
  format: IOFormatRuntimeFormat;
  operation: IOFormatRuntimeOperation;
}

export type IOFormatRuntimeRouteResult =
  | { status: "READY"; format: IOFormatRuntimeFormat; operation: IOFormatRuntimeOperation; operator: string; receipt: IOFormatRuntimeReceiptIR }
  | { status: "BLOCKED"; code: "IO_FORMAT_UNSUPPORTED"; format: IOFormatRuntimeFormat; operation: IOFormatRuntimeOperation };

export class IOFormatRuntimeReceiptError extends Error {
  readonly code = "IO_FORMAT_UNSUPPORTED" as const;

  constructor(message: string) {
    super(`IO_FORMAT_UNSUPPORTED: ${message}`);
    this.name = "IOFormatRuntimeReceiptError";
  }
}

const SHA256 = /^[a-f0-9]{64}$/;
const VERSION = /^[0-9]+\.[0-9]+\.[0-9]+(?:\s+.*)?$/;
const IDENTIFIER = /^[A-Za-z0-9_.:-]+$/;

function record(value: unknown, path: string): Record<string, unknown> {
  if (typeof value !== "object" || value === null || Array.isArray(value)) throw new IOFormatRuntimeReceiptError(`${path} must be an object`);
  return value as Record<string, unknown>;
}

function exactKeys(value: Record<string, unknown>, expected: readonly string[], path: string): void {
  const actual = Object.keys(value).sort();
  const allowed = [...expected].sort();
  if (actual.length !== allowed.length || actual.some((key, index) => key !== allowed[index])) throw new IOFormatRuntimeReceiptError(`${path} contains undeclared fields`);
}

function nonEmpty(value: unknown, path: string, maximum = 256): string {
  if (typeof value !== "string" || value.length === 0 || value.length > maximum) throw new IOFormatRuntimeReceiptError(`${path} is invalid`);
  return value;
}

function sha(value: unknown, path: string): string {
  if (typeof value !== "string" || !SHA256.test(value)) throw new IOFormatRuntimeReceiptError(`${path} is not SHA-256`);
  return value;
}

function parseRuntime(value: unknown): IOFormatRuntimeIdentityIR {
  const input = record(value, "runtime");
  exactKeys(input, ["blenderVersion", "versionTuple", "buildHash", "buildBranch", "buildPlatform", "buildType", "buildDate", "buildTime", "buildCommitTimestamp", "binarySha256", "buildOptions"], "runtime");
  if (typeof input.blenderVersion !== "string" || !VERSION.test(input.blenderVersion)) throw new IOFormatRuntimeReceiptError("runtime.blenderVersion is invalid");
  if (!Array.isArray(input.versionTuple) || input.versionTuple.length !== 3 || input.versionTuple.some((part) => !Number.isSafeInteger(part) || (part as number) < 0)) throw new IOFormatRuntimeReceiptError("runtime.versionTuple is invalid");
  const buildOptions = record(input.buildOptions, "runtime.buildOptions");
  const parsedOptions: Record<string, boolean> = {};
  for (const key of Object.keys(buildOptions).sort()) {
    if (!IDENTIFIER.test(key) || typeof buildOptions[key] !== "boolean") throw new IOFormatRuntimeReceiptError("runtime.buildOptions is invalid");
    parsedOptions[key] = buildOptions[key] as boolean;
  }
  if (!Number.isSafeInteger(input.buildCommitTimestamp) || (input.buildCommitTimestamp as number) < 0) throw new IOFormatRuntimeReceiptError("runtime.buildCommitTimestamp is invalid");
  return {
    blenderVersion: input.blenderVersion,
    versionTuple: [...input.versionTuple] as [number, number, number],
    buildHash: nonEmpty(input.buildHash, "runtime.buildHash"),
    buildBranch: nonEmpty(input.buildBranch, "runtime.buildBranch"),
    buildPlatform: nonEmpty(input.buildPlatform, "runtime.buildPlatform"),
    buildType: nonEmpty(input.buildType, "runtime.buildType"),
    buildDate: nonEmpty(input.buildDate, "runtime.buildDate"),
    buildTime: nonEmpty(input.buildTime, "runtime.buildTime"),
    buildCommitTimestamp: input.buildCommitTimestamp as number,
    binarySha256: sha(input.binarySha256, "runtime.binarySha256"),
    buildOptions: parsedOptions,
  };
}

function parseReceipt(value: unknown, index: number): IOFormatRuntimeReceiptIR {
  const path = `receipts[${index}]`;
  const input = record(value, path);
  exactKeys(input, ["format", "family", "operation", "operator", "registered", "rnaIdentifier", "buildOption", "buildOptionEnabled", "runtimeStatus", "variants", "extensions"], path);
  if (!IO_FORMAT_RUNTIME_FORMATS.includes(input.format as IOFormatRuntimeFormat) || !["IMPORT", "EXPORT"].includes(input.operation as string)) throw new IOFormatRuntimeReceiptError(`${path} identity is invalid`);
  if (typeof input.registered !== "boolean" || !["AVAILABLE", "OPERATOR_UNREGISTERED"].includes(input.runtimeStatus as string)) throw new IOFormatRuntimeReceiptError(`${path} registration status is invalid`);
  if (input.rnaIdentifier !== null && (typeof input.rnaIdentifier !== "string" || !IDENTIFIER.test(input.rnaIdentifier))) throw new IOFormatRuntimeReceiptError(`${path}.rnaIdentifier is invalid`);
  if (input.buildOption !== null && (typeof input.buildOption !== "string" || !IDENTIFIER.test(input.buildOption))) throw new IOFormatRuntimeReceiptError(`${path}.buildOption is invalid`);
  if (input.buildOptionEnabled !== null && typeof input.buildOptionEnabled !== "boolean") throw new IOFormatRuntimeReceiptError(`${path}.buildOptionEnabled is invalid`);
  if (!Array.isArray(input.variants) || input.variants.length === 0 || input.variants.some((variant) => typeof variant !== "string" || !IDENTIFIER.test(variant))) throw new IOFormatRuntimeReceiptError(`${path}.variants are invalid`);
  if (!Array.isArray(input.extensions) || input.extensions.length === 0 || input.extensions.some((extension) => typeof extension !== "string" || !/^\.[a-z0-9]+$/.test(extension))) throw new IOFormatRuntimeReceiptError(`${path}.extensions are invalid`);
  const available = input.runtimeStatus === "AVAILABLE";
  if (available !== input.registered || (available && input.rnaIdentifier === null) || (!available && input.rnaIdentifier !== null) || (!available && input.buildOptionEnabled !== null)) throw new IOFormatRuntimeReceiptError(`${path} has inconsistent runtime receipt state`);
  return {
    format: input.format as IOFormatRuntimeFormat,
    family: nonEmpty(input.family, `${path}.family`),
    operation: input.operation as IOFormatRuntimeOperation,
    operator: nonEmpty(input.operator, `${path}.operator`),
    registered: input.registered as boolean,
    rnaIdentifier: input.rnaIdentifier as string | null,
    buildOption: input.buildOption as string | null,
    buildOptionEnabled: input.buildOptionEnabled as boolean | null,
    runtimeStatus: input.runtimeStatus as IOFormatRuntimeStatus,
    variants: [...input.variants as string[]],
    extensions: [...input.extensions as string[]],
  };
}

export function parseIOFormatRuntimeReceiptSet(value: unknown): IOFormatRuntimeReceiptSetIR {
  const input = record(value, "input");
  exactKeys(input, ["schemaVersion", "task", "inventorySha256", "runtime", "receipts"], "input");
  if (input.schemaVersion !== IO_FORMAT_RUNTIME_RECEIPT_SCHEMA || input.task !== IO_FORMAT_RUNTIME_RECEIPT_TASK) throw new IOFormatRuntimeReceiptError("receipt set header is invalid");
  const receipts = Array.isArray(input.receipts) ? input.receipts.map(parseReceipt) : (() => { throw new IOFormatRuntimeReceiptError("input.receipts must be an array"); })();
  if (typeof input.inventorySha256 !== "string" || !SHA256.test(input.inventorySha256)) throw new IOFormatRuntimeReceiptError("input.inventorySha256 is invalid");
  if (receipts.length !== IO_FORMAT_RUNTIME_FORMATS.length * 2) throw new IOFormatRuntimeReceiptError("receipt set must contain one import and export receipt per format");
  const identities = receipts.map((receipt) => `${receipt.format}:${receipt.operation}`);
  if (new Set(identities).size !== identities.length || IO_FORMAT_RUNTIME_FORMATS.some((format) => !["IMPORT", "EXPORT"].every((operation) => identities.includes(`${format}:${operation}`)))) throw new IOFormatRuntimeReceiptError("receipt identities are incomplete or duplicated");
  return { schemaVersion: IO_FORMAT_RUNTIME_RECEIPT_SCHEMA, task: IO_FORMAT_RUNTIME_RECEIPT_TASK, inventorySha256: input.inventorySha256, runtime: parseRuntime(input.runtime), receipts };
}

export function validateIOFormatRuntimeReceiptSet(value: unknown, expectedInventorySha256: string): IOFormatRuntimeReceiptSetIR {
  if (!SHA256.test(expectedInventorySha256)) throw new IOFormatRuntimeReceiptError("expected inventory SHA-256 is invalid");
  const parsed = parseIOFormatRuntimeReceiptSet(value);
  if (parsed.inventorySha256 !== expectedInventorySha256) throw new IOFormatRuntimeReceiptError("runtime receipt inventory identity does not match");
  return parsed;
}

export function resolveIOFormatRuntimeRoute(receiptSet: IOFormatRuntimeReceiptSetIR, query: IOFormatRuntimeRouteQuery): IOFormatRuntimeRouteResult {
  const receipt = receiptSet.receipts.find((candidate) => candidate.format === query.format && candidate.operation === query.operation);
  if (!receipt || receipt.runtimeStatus !== "AVAILABLE" || receipt.registered !== true || receipt.rnaIdentifier === null || receipt.buildOptionEnabled === false) return { status: "BLOCKED", code: "IO_FORMAT_UNSUPPORTED", format: query.format, operation: query.operation };
  return { status: "READY", format: query.format, operation: query.operation, operator: receipt.operator, receipt };
}