import { mkdir, readdir, readFile, rm, stat, writeFile } from "node:fs/promises";
import path from "node:path";
import { parse as parseYaml, stringify as stringifyYaml } from "yaml";
import { AgentRunError } from "./errors.js";
import type { AipodSpec, AipodSpecRecord, BackendProfile, CreateQueueTaskInput, ExecutionPolicy, JsonRecord, JsonValue, RenderAipodInput, RenderedAipodQueueTask, ResourceBundleRef, SessionRef, WorkspaceRef } from "./types.js";
import { backendProfileSpec, isBackendProfile } from "./backend-profiles.js";
import { imageRefSourceSummary, validateAipodImageRef } from "./env-image-ref.js";
import { asRecord, stableHash, validateCreateQueueTask, validateExecutionPolicy, validateResourceBundleRef, validateSessionRef } from "./validation.js";

const aipodApiVersion = "agentrun.pikastech.local/v0.1";
const aipodKind = "AipodSpec";

export function aipodSpecDirectory(): string {
  return process.env.AGENTRUN_AIPOD_SPEC_DIR ?? path.join(process.cwd(), "config", "aipods");
}

export async function listAipodSpecs(dir = aipodSpecDirectory()): Promise<JsonRecord> {
  const records = await loadAipodSpecRecords(dir);
  return {
    action: "aipod-spec-list",
    dir,
    count: records.length,
    items: records.map((record) => summarizeAipodSpecRecord(record)),
    valuesPrinted: false,
  };
}

export async function showAipodSpec(name: string, dir = aipodSpecDirectory()): Promise<JsonRecord> {
  const record = await getAipodSpecRecord(name, dir);
  return { action: "aipod-spec-show", item: summarizeAipodSpecRecord(record), spec: record.spec, valuesPrinted: false };
}

export async function renderAipodSpecByName(name: string, input: RenderAipodInput = {}, dir = aipodSpecDirectory()): Promise<RenderedAipodQueueTask> {
  const record = await getAipodSpecRecord(name, dir);
  return renderAipodSpec(record, input);
}

export async function applyAipodSpec(input: unknown, dir = aipodSpecDirectory()): Promise<JsonRecord> {
  const spec = aipodSpecFromInput(input, "api");
  await mkdir(dir, { recursive: true });
  const file = path.join(dir, `${fileSafeAipodName(spec.metadata.name)}.yaml`);
  await writeFile(file, stringifyYaml(spec), "utf8");
  const record = await loadAipodSpecFile(file);
  return { action: "aipod-spec-apply", mutation: true, item: summarizeAipodSpecRecord(record), valuesPrinted: false };
}

export async function deleteAipodSpec(name: string, dir = aipodSpecDirectory()): Promise<JsonRecord> {
  const record = await getAipodSpecRecord(name, dir);
  await rm(record.source, { force: true });
  return { action: "aipod-spec-delete", mutation: true, name: record.name, source: record.source, specHash: record.specHash, valuesPrinted: false };
}

export function parseAipodSpecYaml(text: string, source = "stdin"): AipodSpec {
  let parsed: unknown;
  try {
    parsed = parseYaml(text);
  } catch (error) {
    throw new AgentRunError("schema-invalid", `aipod-spec YAML parse failed: ${error instanceof Error ? error.message : String(error)}`, { httpStatus: 400, details: { source, valuesPrinted: false } });
  }
  return validateAipodSpec(parsed, source);
}

export function aipodSpecFromInput(input: unknown, source = "inline"): AipodSpec {
  const record = asRecord(input, "aipodSpecInput");
  if (typeof record.yaml === "string") return parseAipodSpecYaml(record.yaml, source);
  if (record.spec !== undefined) return validateAipodSpec(record.spec, source);
  return validateAipodSpec(record, source);
}

export function validateAipodSpec(input: unknown, source = "inline"): AipodSpec {
  const record = asRecord(input, "aipodSpec");
  if (stringValue(record.apiVersion) !== aipodApiVersion) throw new AgentRunError("schema-invalid", `aipodSpec.apiVersion must be ${aipodApiVersion}`, { httpStatus: 400, details: { source } });
  if (stringValue(record.kind) !== aipodKind) throw new AgentRunError("schema-invalid", `aipodSpec.kind must be ${aipodKind}`, { httpStatus: 400, details: { source } });
  const metadata = asRecord(record.metadata, "aipodSpec.metadata");
  const name = validateAipodName(requiredString(metadata, "name"));
  const labels = metadata.labels === undefined ? undefined : asRecord(metadata.labels, "aipodSpec.metadata.labels");
  const spec = asRecord(record.spec, "aipodSpec.spec");
  const backendProfile = normalizeBackendProfile(requiredString(spec, "backendProfile"));
  const imageRef = validateAipodImageRef(spec.imageRef, "aipodSpec.spec.imageRef");
  const executionPolicy = validateExecutionPolicy(asRecord(spec.executionPolicy, "aipodSpec.spec.executionPolicy"));
  validateAipodProviderCredential(backendProfile, executionPolicy);
  const resourceBundleRef = validateResourceBundleRef(spec.resourceBundleRef);
  const result: AipodSpec = {
    apiVersion: aipodApiVersion,
    kind: aipodKind,
    metadata: {
      name,
      ...(stringValue(metadata.displayName) ? { displayName: stringValue(metadata.displayName) as string } : {}),
      ...(stringValue(metadata.description) ? { description: stringValue(metadata.description) as string } : {}),
      ...(labels ? { labels } : {}),
    },
    spec: {
      ...(stringValue(spec.tenantId) ? { tenantId: stringValue(spec.tenantId) as string } : {}),
      ...(stringValue(spec.projectId) ? { projectId: stringValue(spec.projectId) as string } : {}),
      ...(stringValue(spec.queue) ? { queue: stringValue(spec.queue) as string } : {}),
      ...(stringValue(spec.lane) ? { lane: stringValue(spec.lane) as string } : {}),
      ...(typeof spec.priority === "number" ? { priority: spec.priority } : {}),
      ...(stringValue(spec.providerId) ? { providerId: stringValue(spec.providerId) as string } : {}),
      backendProfile,
      ...(isJsonRecord(spec.model) ? { model: spec.model } : {}),
      imageRef,
      ...(isJsonRecord(spec.workspaceRef) ? { workspaceRef: validateWorkspaceRef(spec.workspaceRef) } : {}),
      ...(spec.sessionRef !== undefined ? { sessionRef: validateSessionRef(spec.sessionRef) } : {}),
      executionPolicy,
      resourceBundleRef,
      ...(isJsonRecord(spec.payloadDefaults) ? { payloadDefaults: spec.payloadDefaults } : {}),
      ...(Array.isArray(spec.references) ? { references: spec.references.map((item, index) => asRecord(item, `aipodSpec.spec.references[${index}]`)) } : {}),
      ...(isJsonRecord(spec.metadata) ? { metadata: spec.metadata } : {}),
      ...(isJsonRecord(spec.dispatchDefaults) ? { dispatchDefaults: spec.dispatchDefaults } : {}),
    },
  };
  return result;
}

export function renderAipodSpec(record: AipodSpecRecord, input: RenderAipodInput = {}): RenderedAipodQueueTask {
  const spec = record.spec.spec;
  const imageRef = imageRefSourceSummary(spec.imageRef);
  const metadata = mergeRecords(spec.metadata, input.metadata, { aipod: record.name, aipodSpecHash: record.specHash, aipodImageRef: imageRef });
  const payload = mergeRecords(spec.payloadDefaults, input.payload);
  if (typeof input.prompt === "string" && input.prompt.trim().length > 0) payload.prompt = input.prompt;
  applyModelPayload(payload, spec.model);
  const sessionRef = renderSessionRef(spec.sessionRef ?? null, input, record, payload);
  const queueTask = validateCreateQueueTask({
    tenantId: input.tenantId ?? spec.tenantId ?? "unidesk",
    projectId: input.projectId ?? spec.projectId ?? "default",
    queue: input.queue ?? spec.queue ?? "commander",
    lane: input.lane ?? spec.lane ?? "v0.1",
    title: input.title ?? stringValue(payload.title) ?? record.spec.metadata.displayName ?? record.name,
    priority: input.priority ?? spec.priority ?? 50,
    backendProfile: input.backendProfile ?? spec.backendProfile,
    providerId: input.providerId ?? spec.providerId ?? "G14",
    workspaceRef: input.workspaceRef ?? spec.workspaceRef ?? { kind: "opaque", path: "." },
    sessionRef,
    executionPolicy: spec.executionPolicy,
    resourceBundleRef: spec.resourceBundleRef,
    payload,
    references: [...(spec.references ?? []), ...(input.references ?? [])],
    metadata,
    ...(input.idempotencyKey ? { idempotencyKey: input.idempotencyKey } : {}),
  }) as CreateQueueTaskInput;
  return {
    action: "aipod-spec-render",
    aipod: summarizeAipodSpecRecord(record),
    queueTask,
    dispatchDefaults: aipodDispatchDefaults(spec.dispatchDefaults, spec.imageRef),
    valuesPrinted: false,
  };
}

export function summarizeAipodSpecRecord(record: AipodSpecRecord): JsonRecord {
  const spec = record.spec.spec;
  return {
    name: record.name,
    displayName: record.spec.metadata.displayName ?? record.name,
    description: record.spec.metadata.description ?? null,
    specHash: record.specHash,
    source: record.source,
    backendProfile: spec.backendProfile,
    model: spec.model ?? null,
    imageRef: imageRefSourceSummary(spec.imageRef),
    queue: spec.queue ?? "commander",
    lane: spec.lane ?? "v0.1",
    providerId: spec.providerId ?? "G14",
    providerCredentials: summarizeProviderCredentials(spec.executionPolicy),
    toolCredentials: summarizeToolCredentials(spec.executionPolicy),
    resourceBundleRef: summarizeResourceBundle(spec.resourceBundleRef),
    dispatchDefaults: summarizeKeys(spec.dispatchDefaults),
    createdAt: record.createdAt,
    updatedAt: record.updatedAt,
    valuesPrinted: false,
  };
}

async function loadAipodSpecRecords(dir: string): Promise<AipodSpecRecord[]> {
  let entries;
  try {
    entries = await readdir(dir, { withFileTypes: true });
  } catch (error) {
    if (isNotFound(error)) return [];
    throw error;
  }
  const records = await Promise.all(entries
    .filter((entry) => entry.isFile() && /\.ya?ml$/u.test(entry.name))
    .sort((left, right) => left.name.localeCompare(right.name))
    .map((entry) => loadAipodSpecFile(path.join(dir, entry.name))));
  return records.sort((left, right) => left.name.localeCompare(right.name));
}

async function getAipodSpecRecord(name: string, dir: string): Promise<AipodSpecRecord> {
  const lookup = normalizeLookupName(name);
  const records = await loadAipodSpecRecords(dir);
  const match = records.find((record) => normalizeLookupName(record.name) === lookup);
  if (!match) throw new AgentRunError("schema-invalid", `aipod-spec ${name} was not found`, { httpStatus: 404, details: { dir, available: records.map((record) => record.name), valuesPrinted: false } });
  return match;
}

async function loadAipodSpecFile(file: string): Promise<AipodSpecRecord> {
  const text = await readFile(file, "utf8");
  const spec = parseAipodSpecYaml(text, file);
  const info = await stat(file);
  const updatedAt = info.mtime.toISOString();
  return { name: spec.metadata.name, spec, specHash: stableHash(spec), source: file, createdAt: info.birthtime.toISOString(), updatedAt };
}

function validateAipodProviderCredential(profile: BackendProfile, policy: ExecutionPolicy): void {
  const matching = (policy.secretScope.providerCredentials ?? []).filter((item) => item.profile === profile);
  if (matching.length !== 1) {
    throw new AgentRunError("secret-unavailable", `aipod backendProfile ${profile} requires exactly one matching provider credential SecretRef`, {
      httpStatus: 400,
      details: { profile, matchingCount: matching.length, defaultSecretName: backendProfileSpec(profile)?.defaultSecretName ?? null, valuesPrinted: false },
    });
  }
}

function renderSessionRef(base: SessionRef | null, input: RenderAipodInput, record: AipodSpecRecord, payload: JsonRecord): SessionRef | null {
  if (input.sessionRef !== undefined) return input.sessionRef;
  const sessionId = input.sessionId ?? base?.sessionId ?? defaultAipodSessionId(record, input, payload);
  return { ...(base ?? {}), sessionId, conversationId: base?.conversationId ?? sessionId };
}

function defaultAipodSessionId(record: AipodSpecRecord, input: RenderAipodInput, payload: JsonRecord): string {
  const seed = input.idempotencyKey ?? `${record.name}:${stableHash({ prompt: input.prompt ?? null, payload })}`;
  const suffix = stableHash({ aipod: record.name, seed }).slice(0, 24);
  const name = fileSafeAipodName(record.name).toLowerCase().replace(/[^a-z0-9]+/gu, "_").replace(/^_+|_+$/gu, "") || "aipod";
  return `sess_${name}_${suffix}`;
}

function validateWorkspaceRef(record: JsonRecord): WorkspaceRef {
  const kind = requiredString(record, "kind");
  if (!["git-worktree", "host-path", "kubernetes-pvc", "opaque"].includes(kind)) {
    throw new AgentRunError("schema-invalid", `workspaceRef.kind ${kind} is not supported`, { httpStatus: 400 });
  }
  return record as WorkspaceRef;
}

function summarizeProviderCredentials(policy: ExecutionPolicy): JsonRecord {
  const items = (policy.secretScope.providerCredentials ?? []).map((item) => ({ profile: item.profile, name: item.secretRef.name, namespace: item.secretRef.namespace ?? null, keys: item.secretRef.keys ?? [], valuesPrinted: false }));
  return { count: items.length, profiles: items.map((item) => item.profile), items, valuesPrinted: false };
}

function summarizeToolCredentials(policy: ExecutionPolicy): JsonRecord {
  const items = (policy.secretScope.toolCredentials ?? []).map((item) => ({ tool: item.tool, purpose: item.purpose ?? null, name: item.secretRef.name, namespace: item.secretRef.namespace ?? null, keys: item.secretRef.keys ?? [], projection: item.projection, valuesPrinted: false }));
  return { count: items.length, tools: items.map((item) => item.tool), items, valuesPrinted: false };
}

function summarizeResourceBundle(resourceBundleRef: ResourceBundleRef | null): JsonRecord | null {
  if (!resourceBundleRef) return null;
  return {
    kind: resourceBundleRef.kind,
    repoUrl: resourceBundleRef.repoUrl,
    ref: resourceBundleRef.ref ?? null,
    commitId: resourceBundleRef.commitId ?? null,
    bundles: { count: resourceBundleRef.bundles.length, items: resourceBundleRef.bundles.map((item) => ({ name: item.name ?? null, repoUrl: item.repoUrl ?? resourceBundleRef.repoUrl, ref: item.ref ?? resourceBundleRef.ref ?? null, commitId: item.commitId ?? resourceBundleRef.commitId ?? null, subpath: item.subpath, targetPath: item.targetPath, valuesPrinted: false })), valuesPrinted: false },
    requiredSkills: { count: resourceBundleRef.requiredSkills?.length ?? 0, names: resourceBundleRef.requiredSkills?.map((item) => item.name) ?? [], valuesPrinted: false },
    promptRefs: { count: resourceBundleRef.promptRefs?.length ?? 0, names: resourceBundleRef.promptRefs?.map((item) => item.name) ?? [], valuesPrinted: false },
    valuesPrinted: false,
  };
}

function summarizeKeys(value: JsonRecord | undefined): JsonRecord {
  return { keys: Object.keys(value ?? {}).sort(), valuesPrinted: false };
}

function mergeRecords(...records: Array<JsonRecord | undefined>): JsonRecord {
  return Object.assign({}, ...records.filter(Boolean));
}

function aipodDispatchDefaults(base: JsonRecord | undefined, imageRef: AipodSpec["spec"]["imageRef"]): JsonRecord {
  const result = mergeRecords(base);
  const runnerJob = mergeRecords(isJsonRecord(result.runnerJob) ? result.runnerJob : undefined, { imageRef });
  result.runnerJob = runnerJob;
  return result;
}

function applyModelPayload(payload: JsonRecord, model: JsonRecord | undefined): void {
  if (!model) return;
  const modelName = stringValue(model.model);
  if (modelName) payload.model = modelName;
  payload.modelConfig = { ...model, valuesPrinted: false };
}

function normalizeBackendProfile(value: string): BackendProfile {
  const profile = value.trim().toLowerCase();
  if (!isBackendProfile(profile)) throw new AgentRunError("schema-invalid", `backendProfile ${value} must be a lowercase slug`, { httpStatus: 400 });
  return profile;
}

function validateAipodName(value: string): string {
  if (!/^[A-Za-z][A-Za-z0-9._-]{0,63}$/u.test(value)) throw new AgentRunError("schema-invalid", "aipodSpec.metadata.name must be an aipod name", { httpStatus: 400 });
  return value;
}

function fileSafeAipodName(value: string): string {
  return value.toLowerCase().replace(/[^a-z0-9._-]+/gu, "-").replace(/^-+|-+$/gu, "") || "aipod";
}

function normalizeLookupName(value: string): string {
  return value.trim().toLowerCase();
}

function requiredString(record: JsonRecord, key: string): string {
  const value = record[key];
  if (typeof value !== "string" || value.trim().length === 0) throw new AgentRunError("schema-invalid", `${key} is required`, { httpStatus: 400 });
  return value.trim();
}

function stringValue(value: unknown): string | null {
  return typeof value === "string" && value.trim().length > 0 ? value.trim() : null;
}

function isJsonRecord(value: unknown): value is JsonRecord {
  return typeof value === "object" && value !== null && !Array.isArray(value);
}

function isNotFound(error: unknown): boolean {
  return typeof error === "object" && error !== null && "code" in error && (error as { code?: unknown }).code === "ENOENT";
}