import { dirname } from "node:path";

import {
  buildInstallationContract,
  type InstallationRole,
  type InstallationSuffix,
  type InstallationVariable,
} from "./contracts.js";
import { resolveRuntimeBindings, type RuntimeBindings } from "./bindings.js";
import {
  DWH_TRANSPORTS,
  validateWorkspaceDescriptor,
  type DwhTransport,
  type WorkspaceDescriptor,
} from "./schema.js";
import {
  WorkspaceSecretStore,
  type WorkspaceSecretMaterialization,
} from "./secret-store.js";

export type WorkspaceSecretInput = "password" | "textarea";

export interface WorkspaceSecretRequirement {
  id: string;
  variable: string;
  connector: "dwh" | "evidence";
  label: string;
  description: string;
  input: WorkspaceSecretInput;
  required: boolean;
}

export interface WorkspaceRuntimeBindingLease {
  bindings: RuntimeBindings;
  release(): void;
}

interface RequirementDefinition {
  id: string;
  label: string;
  description: string;
  input: WorkspaceSecretInput;
}

const DEFINITIONS: Readonly<Partial<Record<`${InstallationRole}.${InstallationSuffix}`, RequirementDefinition>>> = {
  "DWH.PASSWORD_FILE": {
    id: "dwh.password",
    label: "Data warehouse password",
    description: "Password used by the selected data warehouse connection.",
    input: "password",
  },
  "DWH.API_KEY_FILE": {
    id: "dwh.api_key",
    label: "Data warehouse API key",
    description: "API key sent to the configured data warehouse REST endpoint.",
    input: "password",
  },
  "DWH.SSH_PRIVATE_KEY_FILE": {
    id: "dwh.ssh_private_key",
    label: "SSH private key",
    description: "Private key used to open the configured SSH tunnel to the data warehouse.",
    input: "textarea",
  },
  "EVIDENCE.SIGNED_URLS_FILE": {
    id: "evidence.signed_urls",
    label: "Evidence signed URLs",
    description: "Signed URLs that authorize ThothII to retrieve the workspace Evidence sources.",
    input: "textarea",
  },
  "EVIDENCE.ACCESS_KEY_FILE": {
    id: "evidence.access_key",
    label: "Evidence access key",
    description: "Access-key identifier used for the configured S3 Evidence source.",
    input: "password",
  },
  "EVIDENCE.SECRET_KEY_FILE": {
    id: "evidence.secret_key",
    label: "Evidence secret key",
    description: "Secret access key used for the configured S3 Evidence source.",
    input: "password",
  },
  "EVIDENCE.SESSION_TOKEN_FILE": {
    id: "evidence.session_token",
    label: "Evidence session token",
    description: "Optional temporary session token used with the S3 Evidence credentials.",
    input: "password",
  },
};

const REQUIRED_DWH_SECRETS: Readonly<Record<DwhTransport, readonly InstallationSuffix[]>> = {
  postgres_direct: ["PASSWORD_FILE"],
  rest_api: ["API_KEY_FILE"],
  ssh_tunnel: ["PASSWORD_FILE", "SSH_PRIVATE_KEY_FILE"],
};

function isTransport(value: string | undefined): value is DwhTransport {
  return value !== undefined && (DWH_TRANSPORTS as readonly string[]).includes(value);
}

function selectedTransport(
  descriptor: WorkspaceDescriptor,
  variables: readonly InstallationVariable[],
  env: NodeJS.ProcessEnv,
): DwhTransport {
  const transportVariable = variables.find(({ role, suffix }) => role === "DWH" && suffix === "TRANSPORT");
  const value = transportVariable === undefined ? undefined : env[transportVariable.name];
  return isTransport(value) && descriptor.dwh.supported_transports.includes(value)
    ? value
    : descriptor.dwh.supported_transports[0];
}

function requirementFor(
  variable: InstallationVariable,
  required: boolean,
): WorkspaceSecretRequirement | undefined {
  const definition = DEFINITIONS[`${variable.role}.${variable.suffix}`];
  if (definition === undefined) return undefined;
  return {
    ...definition,
    variable: variable.name,
    connector: variable.role === "DWH" ? "dwh" : "evidence",
    required,
  };
}

/**
 * Discover the credential fields for the connector and authentication mechanisms selected by
 * this installation. Paths, hostnames and trust files remain installation configuration rather
 * than user-entered secrets.
 */
export function discoverWorkspaceSecretRequirements(
  workspace: WorkspaceDescriptor,
  env: NodeJS.ProcessEnv,
): WorkspaceSecretRequirement[] {
  const descriptor = validateWorkspaceDescriptor(workspace);
  const variables = buildInstallationContract(descriptor).variables;
  const transport = selectedTransport(descriptor, variables, env);
  const restHasNoAuthentication = transport === "rest_api" && descriptor.diagnostics?.dwh_rest?.auth === "none";
  const requiredDwh = new Set(restHasNoAuthentication ? [] : REQUIRED_DWH_SECRETS[transport]);

  const requirements: WorkspaceSecretRequirement[] = [];
  for (const variable of variables) {
    if (variable.role === "DWH") {
      if (variable.transports !== undefined && !variable.transports.includes(transport)) continue;
      const requirement = requirementFor(variable, requiredDwh.has(variable.suffix));
      if (requirement !== undefined && requirement.required) requirements.push(requirement);
      continue;
    }
    const requirement = requirementFor(variable, variable.suffix !== "SESSION_TOKEN_FILE");
    if (requirement !== undefined) requirements.push(requirement);
  }
  return requirements;
}

/**
 * Materialize only the selected workspace credentials, translate them to the existing file-based
 * harness contract, and bind cleanup to the returned lease.
 */
export function resolveRuntimeBindingsWithWorkspaceSecrets(
  workspace: WorkspaceDescriptor,
  env: NodeJS.ProcessEnv,
  secretRoots: readonly string[],
  store: WorkspaceSecretStore,
): WorkspaceRuntimeBindingLease {
  const descriptor = validateWorkspaceDescriptor(workspace);
  const requirements = discoverWorkspaceSecretRequirements(descriptor, env);
  let materialization: WorkspaceSecretMaterialization | undefined;
  try {
    materialization = store.materialize(
      descriptor.workspace.id,
      requirements.map(({ id }) => id),
    );
    const effectiveEnvironment: NodeJS.ProcessEnv = { ...env };
    const materializedRoots = new Set<string>();
    for (const requirement of requirements) {
      const path = materialization.files.get(requirement.id);
      if (path === undefined) continue;
      effectiveEnvironment[requirement.variable] = path;
      materializedRoots.add(dirname(path));
    }
    const bindings = resolveRuntimeBindings(
      descriptor,
      effectiveEnvironment,
      [...secretRoots, ...materializedRoots],
    );
    let released = false;
    return {
      bindings,
      release: () => {
        if (released) return;
        released = true;
        materialization?.release();
      },
    };
  } catch (error) {
    materialization?.release();
    throw error;
  }
}