import type {
  DependencyCatalogResponse,
  DependencyPlanStepViewResponse,
  DependencyPlanViewResponse,
  DependencyProbeViewResponse,
  DependencyState,
  RunUpdateJobListResponse,
  RunUpdateJobResponse,
  RunUpdatePhase
} from "../api/types";

const dependencyStates = new Set<DependencyState>(["unknown", "present", "missing", "installing", "failed"]);
const updatePhases = new Set<RunUpdatePhase>(["queued", "downloading", "staged", "restart-requested", "activating", "succeeded", "rolled-back", "failed"]);
const updateStatuses = new Set(["queued", "running", "succeeded", "failed", "denied"]);
const forbiddenProjectionKeys = new Set([
  "leasetoken",
  "leasetokenhash",
  "leasesessiongeneration",
  "sessiontoken",
  "runtoken",
  "secretref",
  "hostpath",
  "executablepath",
  "stagingpath",
  "backuppath",
  "socket",
  "credential"
]);
export function parseSafeDependencyCatalog(value: unknown): DependencyCatalogResponse {
  const record = requiredRecordValue(value, "dependency catalog");
  rejectForbiddenProjection(record);
  return {
    serverInstanceId: requiredString(record, "serverInstanceId"),
    pluginId: requiredString(record, "pluginId"),
    pluginVersion: requiredString(record, "pluginVersion"),
    profileKey: requiredString(record, "profileKey"),
    targetOs: requiredString(record, "targetOs"),
    targetArch: requiredString(record, "targetArch"),
    probes: requiredArray(record, "probes").map(parseDependencyProbe),
    plans: requiredArray(record, "plans").map(parseDependencyPlan),
    updatedAt: requiredString(record, "updatedAt")
  };
}

export function parseSafeRunUpdateList(value: unknown): RunUpdateJobListResponse {
  const record = requiredRecordValue(value, "Run update list");
  rejectForbiddenProjection(record);
  const items = requiredArray(record, "items").map((item) => parseRunUpdate(requiredRecordValue(item, "Run update")));
  const count = requiredNumber(record, "count");
  if (count !== items.length) throw new Error("Run update count does not match items");
  return { items, count };
}

export function parseSafeRunUpdate(value: unknown): RunUpdateJobResponse {
  const record = requiredRecordValue(value, "Run update");
  rejectForbiddenProjection(record);
  return parseRunUpdate(record);
}

function parseDependencyProbe(value: unknown): DependencyProbeViewResponse {
  const record = requiredRecordValue(value, "dependency probe");
  const state = requiredString(record, "state") as DependencyState;
  if (!dependencyStates.has(state)) throw new Error("dependency state is invalid");
  return {
    key: requiredString(record, "key"),
    kind: requiredString(record, "kind"),
    required: requiredBoolean(record, "required"),
    minimumVersion: optionalString(record, "minimumVersion"),
    state,
    evidence: optionalString(record, "evidence"),
    installPlanKey: optionalString(record, "installPlanKey")
  };
}

function parseDependencyPlan(value: unknown): DependencyPlanViewResponse {
  const record = requiredRecordValue(value, "dependency plan");
  return {
    key: requiredString(record, "key"),
    title: requiredString(record, "title"),
    targetOs: requiredString(record, "targetOs"),
    targetArch: requiredString(record, "targetArch"),
    digest: requiredChecksum(record, "digest"),
    steps: requiredArray(record, "steps").map(parseDependencyStep)
  };
}

function parseDependencyStep(value: unknown): DependencyPlanStepViewResponse {
  const record = requiredRecordValue(value, "dependency plan step");
  const downloadHost = optionalString(record, "downloadHost");
  if (downloadHost && (downloadHost.includes("/") || downloadHost.includes("@") || downloadHost.includes(":"))) throw new Error("dependency download host is invalid");
  return {
    type: requiredString(record, "type"),
    targetKey: requiredString(record, "targetKey"),
    packageManager: optionalString(record, "packageManager"),
    packageName: optionalString(record, "packageName"),
    version: optionalString(record, "version"),
    downloadHost,
    sizeBytes: optionalNumber(record, "sizeBytes")
  };
}

function parseRunUpdate(record: Record<string, unknown>): RunUpdateJobResponse {
  const phase = requiredString(record, "phase") as RunUpdatePhase;
  if (!updatePhases.has(phase)) throw new Error("Run update phase is invalid");
  const status = requiredString(record, "status");
  if (!updateStatuses.has(status)) throw new Error("Run update status is invalid");
  return {
    id: requiredString(record, "id"),
    serverInstanceId: requiredString(record, "serverInstanceId"),
    runEndpointId: requiredString(record, "runEndpointId"),
    artifactId: requiredString(record, "artifactId"),
    checksum: requiredChecksum(record, "checksum"),
    targetOs: requiredString(record, "targetOs"),
    targetArch: requiredString(record, "targetArch"),
    targetRelease: optionalString(record, "targetRelease"),
    previousVersion: optionalString(record, "previousVersion"),
    jobId: optionalString(record, "jobId"),
    idempotencyKey: optionalString(record, "idempotencyKey"),
    status,
    phase,
    message: optionalString(record, "message"),
    rollback: requiredBoolean(record, "rollback"),
    createdAt: requiredString(record, "createdAt"),
    updatedAt: requiredString(record, "updatedAt")
  };
}

function rejectForbiddenProjection(value: unknown): void {
  if (!isRecord(value)) return;
  for (const key of Object.keys(value)) {
    if (forbiddenProjectionKeys.has(key.toLowerCase())) throw new Error(`runtime projection contains forbidden field ${key}`);
  }
}

function requiredRecordValue(value: unknown, label: string): Record<string, unknown> {
  if (!isRecord(value)) throw new Error(`${label} must be an object`);
  return value;
}

function requiredArray(value: Record<string, unknown>, key: string): unknown[] {
  const field = value[key];
  if (!Array.isArray(field)) throw new Error(`${key} must be an array`);
  return field;
}

function requiredString(value: Record<string, unknown>, key: string): string {
  const field = value[key];
  if (typeof field !== "string" || field.trim() === "") throw new Error(`${key} must be a non-empty string`);
  return field;
}

function optionalString(value: Record<string, unknown>, key: string): string | undefined {
  const field = value[key];
  if (field === undefined) return undefined;
  if (typeof field !== "string") throw new Error(`${key} must be a string`);
  return field;
}

function requiredChecksum(value: Record<string, unknown>, key: string): string {
  const field = requiredString(value, key);
  if (!/^sha256:[a-f0-9]{64}$/.test(field)) throw new Error(`${key} must be a SHA-256 checksum`);
  return field;
}

function requiredNumber(value: Record<string, unknown>, key: string): number {
  const field = value[key];
  if (typeof field !== "number" || !Number.isFinite(field) || field < 0) throw new Error(`${key} must be a non-negative number`);
  return field;
}

function optionalNumber(value: Record<string, unknown>, key: string): number | undefined {
  if (value[key] === undefined) return undefined;
  return requiredNumber(value, key);
}

function requiredBoolean(value: Record<string, unknown>, key: string): boolean {
  const field = value[key];
  if (typeof field !== "boolean") throw new Error(`${key} must be a boolean`);
  return field;
}

function isRecord(value: unknown): value is Record<string, unknown> {
  return typeof value === "object" && value !== null && !Array.isArray(value);
}