import { basename } from "node:path";
import { absoluteCallerPath } from "../filesystem/callerPath.js";
import type { EnvironmentExportResult } from "../application/environment/environmentExport.js";
import type { EnvironmentSource } from "../application/environment/environmentSource.js";
import type { ServedState } from "../application/environment/environmentState.js";
import { z } from "incur";
import type { Logger } from "pino";

import { CLI_COMMANDS } from "../cliCommandNames.js";
import { parseCliJsonInput } from "../cliJsonInput.js";
import { logCliCommand } from "../cliLogging.js";
import { parseEnvironmentName } from "../config/environmentName.js";
import {
  parseMcpHttpEndpoint,
  mcpHttpListenerPortSchema,
  type McpHttpEndpoint,
} from "../config/mcpHttpEndpoint.js";
import type { AnalysisError } from "../domain/analysisErrorBase.js";
import type { StreamableHttpListenError } from "../server/http/streamableHttpListenError.js";
import {
  AnalysisCancelledError,
  AnalysisResourceConstraintError,
} from "../domain/analysisErrorCore.js";
import { projectAnalysisError } from "../domain/analysisErrorProjection.js";
import type { JsonValue } from "../domain/jsonValue.js";
import { err, ok, type Result } from "../domain/result.js";
import { createLogger } from "../logger.js";
import { withCommandCancellation } from "./commandCancellation.js";
import type { CliInstance } from "./types.js";

/** Same envelope label as the other JSON-input commands and `parseCliJsonInput`. */
const cliError = (error: AnalysisError): JsonValue => ({
  error: "Application workflow failed",
  ...projectAnalysisError(error),
});

/** The listener announces its URL at info like `rea mcp --http`; an explicit REA_LOG_LEVEL still wins. */
const listenerLogger = (
  environment: Readonly<NodeJS.ProcessEnv>,
  logger: Logger,
): Logger =>
  environment.REA_LOG_LEVEL === undefined
    ? createLogger("cli", "info")
    : logger;

/** Resolve until the one-shot signal requests shutdown. */
const untilAborted = (signal: AbortSignal): Promise<undefined> =>
  new Promise((resolve) => {
    if (signal.aborted) resolve(undefined);
    else
      signal.addEventListener("abort", () => resolve(undefined), {
        once: true,
      });
  });

/** A listener failure as the command's typed refusal. */
export const transportError = (
  endpoint: McpHttpEndpoint,
  cause: StreamableHttpListenError,
): AnalysisResourceConstraintError =>
  new AnalysisResourceConstraintError(
    CLI_COMMANDS.environmentServe,
    "transport",
    cause.message,
    { host: endpoint.host, port: endpoint.port },
    {
      cause,
      retryable: false,
      diagnostics: {
        listener_failure: cause.classification.ok
          ? {
              kind: cause.classification.value.kind,
              system_code: cause.classification.value.systemCode,
            }
          : {
              kind: cause.classification.error.kind,
              ...(cause.classification.error.systemCode === undefined
                ? {}
                : { system_code: cause.classification.error.systemCode }),
            },
        listener_phase: cause.phase,
      },
      remediationAction: listenerRemediation(cause.classification),
    },
  );

const listenerRemediation = (
  classification: StreamableHttpListenError["classification"],
): string => {
  if (!classification.ok)
    return "Check the selected listener host, port, and binding permissions, then retry.";
  switch (classification.value.kind) {
    case "host_lookup":
      return "Check --host or MCP_HOST and host name resolution; correct the value or resolve the lookup failure, then retry.";
    case "host_unavailable":
      return "Choose an address assigned to this machine with --host or MCP_HOST, then retry.";
    case "port_in_use":
      return "Choose another --port or MCP_PORT, or stop the process using it.";
    case "permission_denied":
      return "Choose a host and port this process is permitted to bind; if the selected port is restricted, use an allowed port.";
  }
};

interface ServeArguments {
  readonly manifest: string;
  readonly evidence: string;
  readonly replayOnly: boolean;
  readonly host?: string | undefined;
  readonly port?: number | undefined;
}

interface ServeInputs {
  readonly source: EnvironmentSource;
  readonly served: ServedState;
}

const cancelledServe = (): JsonValue =>
  cliError(new AnalysisCancelledError(CLI_COMMANDS.environmentServe));

/** Pure replay, as `--replay-only` asks for: no state is derived. */
const REPLAY_ONLY: ServedState = {
  state: undefined,
  report: { served: false, reason: "replay-only" },
};

/** Read and authenticate the manifest and capture, then prepare the state under the served name unless pure replay is asked for; a refusal is the command's output. */
const loadServeInputs = async (
  input: ServeArguments,
  environmentName: string | undefined,
  signal: AbortSignal,
): Promise<Result<ServeInputs, JsonValue>> => {
  const read = (path: string) =>
    parseCliJsonInput(path, CLI_COMMANDS.environmentServe, signal, {
      snapshot: true,
    });
  const manifest = await read(input.manifest);
  if (!manifest.ok) return manifest;
  const evidence = await read(input.evidence);
  if (!evidence.ok) return evidence;
  const { loadEnvironmentSource } =
    await import("../application/environment/environmentSource.js");
  if (signal.aborted) return err(cancelledServe());
  const source = loadEnvironmentSource(manifest.value, evidence.value);
  if (!source.ok) return err(cliError(source.error));
  if (input.replayOnly)
    return ok({ source: source.value, served: REPLAY_ONLY });
  const { prepareServedState } =
    await import("../application/environment/environmentState.js");
  if (signal.aborted) return err(cancelledServe());
  return ok({
    source: source.value,
    served: prepareServedState(source.value, evidence.value, {
      name: environmentName,
    }),
  });
};

/** Load the Evidence files, bind the listener and run until a signal ends it. */
const serveEnvironmentCommand = async (
  input: ServeArguments,
  environment: Readonly<NodeJS.ProcessEnv>,
  logger: Logger,
  signal: AbortSignal,
): Promise<JsonValue> => {
  if (signal.aborted) return cancelledServe();
  const endpoint = parseMcpHttpEndpoint(environment, {
    ...(input.host === undefined ? {} : { host: input.host }),
    ...(input.port === undefined ? {} : { port: input.port }),
  });
  if (!endpoint.ok) return cliError(endpoint.error);
  const environmentName = parseEnvironmentName(environment);
  if (!environmentName.ok) return cliError(environmentName.error);
  const inputs = await loadServeInputs(input, environmentName.value, signal);
  if (!inputs.ok) return inputs.error;
  const {
    source,
    served: { state, report },
  } = inputs.value;
  const commandLogger = listenerLogger(environment, logger);
  if (!report.served && report.reason === "unavailable")
    commandLogger.warn(
      { code: report.code, error: report.message },
      "Environment state unavailable; serving recorded replay",
    );
  if (signal.aborted) return cancelledServe();
  // Loaded here so registering the command catalog never loads the HTTP listener.
  const { serveEnvironment } =
    await import("../server/environment/serveEnvironment.js");
  const { StreamableHttpListenError } =
    await import("../server/http/streamableHttpListenError.js");
  if (signal.aborted) return cancelledServe();
  // A listener that fails after binding ends the command instead of serving nothing.
  let failListener: (error: StreamableHttpListenError) => void = () =>
    undefined;
  const listenerFailed = new Promise<StreamableHttpListenError>((resolve) => {
    failListener = resolve;
  });
  let served: import("../server/environment/serveEnvironment.js").ServedEnvironment;
  try {
    const started = await serveEnvironment({
      source,
      ...(state === undefined ? {} : { state }),
      signal,
      ...endpoint.value,
      ...(environmentName.value === undefined
        ? {}
        : { environmentName: environmentName.value }),
      logger: commandLogger,
      onerror: failListener,
    });
    if (!started.ok) return cliError(started.error);
    served = started.value;
  } catch (cause: unknown) {
    if (signal.aborted && cause === signal.reason) return cancelledServe();
    if (!(cause instanceof StreamableHttpListenError)) throw cause;
    return cliError(transportError(endpoint.value, cause));
  }
  let failure: StreamableHttpListenError | undefined;
  try {
    failure = await Promise.race([untilAborted(signal), listenerFailed]);
  } finally {
    await served.close();
  }
  if (failure !== undefined)
    return cliError(transportError(endpoint.value, failure));
  return {
    status: "stopped",
    url: served.url,
    environment: served.card.name,
    tools: served.card.capabilities.tools.length,
    evidence_id: source.evidenceId,
    manifest_evidence_id: source.manifestEvidenceId,
    state: report,
  };
};

interface ExportArguments {
  readonly manifest: string;
  readonly evidence: string;
  readonly directory: string;
  readonly packageTarball?: string | undefined;
  readonly name?: string | undefined;
}

/** The written files with sizes, whether the bundle serves the state, and the pinned package source, as the command prints them. */
const exportDocument = (result: EnvironmentExportResult): JsonValue => ({
  status: result.status,
  directory: result.directory,
  name: result.name,
  tool_count: result.tool_count,
  evidence_id: result.evidence_id,
  manifest_evidence_id: result.manifest_evidence_id,
  state: result.state,
  package_source: result.package_source,
  files: result.files.map(({ path, bytes }) => ({ path, bytes })),
});

/** Read each file once, authenticate the pair as the serve command does, then write the bundle from the same bytes. */
const exportEnvironmentCommand = async (
  input: ExportArguments,
): Promise<JsonValue> => {
  const { readEnvironmentExportInputs, exportEnvironmentBundle } =
    await import("../application/environment/environmentExport.js");
  const inputs = await readEnvironmentExportInputs(
    input.manifest,
    input.evidence,
  );
  if (!inputs.ok) return cliError(inputs.error);
  // Loaded here, as for environment-serve, so registering the command catalog never loads it.
  const { loadEnvironmentSource } =
    await import("../application/environment/environmentSource.js");
  const source = loadEnvironmentSource(
    inputs.value.manifest.value,
    inputs.value.evidence.value,
    CLI_COMMANDS.environmentExport,
  );
  if (!source.ok) return cliError(source.error);
  const exported = await exportEnvironmentBundle({
    ...inputs.value,
    source: source.value,
    directory: absoluteCallerPath(input.directory),
    name: input.name,
    packageTarball:
      input.packageTarball === undefined
        ? undefined
        : absoluteCallerPath(input.packageTarball),
  });
  return exported.ok
    ? exportDocument(exported.value)
    : cliError(exported.error);
};

const manifestArgument = z
  .string()
  .describe(
    "Environment manifest Evidence JSON path (inspect-analysis-view environment-manifest output)",
  );
const evidenceOption = z
  .string()
  .describe(
    "Parent capture Evidence JSON path (inspect-web-network-capture or capture-browser-scenario output) the manifest cites",
  );

interface CompareArguments {
  readonly manifest: string;
  readonly evidence: string;
  readonly probes: readonly string[];
}

/** Read the environment and every probe, then compare; a refusal is the command's output. */
const compareEnvironmentCommand = async (
  input: CompareArguments,
): Promise<JsonValue> => {
  const read = (path: string) =>
    parseCliJsonInput(path, CLI_COMMANDS.environmentCompare, undefined, {
      snapshot: true,
    });
  const manifest = await read(input.manifest);
  if (!manifest.ok) return manifest.error;
  const evidence = await read(input.evidence);
  if (!evidence.ok) return evidence.error;
  const probes = [];
  for (const path of input.probes) {
    const probe = await read(path);
    if (!probe.ok) return probe.error;
    probes.push({ label: basename(path), value: probe.value });
  }
  const { loadEnvironmentSource } =
    await import("../application/environment/environmentSource.js");
  const source = loadEnvironmentSource(
    manifest.value,
    evidence.value,
    CLI_COMMANDS.environmentCompare,
  );
  if (!source.ok) return cliError(source.error);
  const { compareEnvironment } =
    await import("../application/environment/environmentCompare.js");
  const report = compareEnvironment({
    source: source.value,
    captureValue: evidence.value,
    probes,
    operation: CLI_COMMANDS.environmentCompare,
  });
  return report.ok
    ? (report.value as unknown as JsonValue)
    : cliError(report.error);
};

/** Register the comparison of an environment with probe captures of its application. */
const registerCompareCommand = (cli: CliInstance, logger: Logger): void => {
  cli.command(CLI_COMMANDS.environmentCompare, {
    description:
      "Compare an environment with probe captures of the application it was captured from: each probe is one call sequence recorded against a freshly reset application, answered by the environment from a reset state, with agreement reported per step, tool and probe",
    args: z.object({ manifest: manifestArgument }),
    options: z.object({
      evidence: evidenceOption,
      probe: z
        .array(z.string())
        .min(1)
        .describe(
          "Probe capture Evidence JSON path (inspect-web-network-capture or capture-browser-scenario output) of one call sequence made against a freshly reset application; repeat once per sequence",
        ),
    }),
    run: ({ args, options }) =>
      logCliCommand(logger, CLI_COMMANDS.environmentCompare, () =>
        compareEnvironmentCommand({
          manifest: args.manifest,
          evidence: options.evidence,
          probes: options.probe,
        }),
      ),
  });
};

/** Register the one-shot bundle export command. */
const registerExportCommand = (cli: CliInstance, logger: Logger): void => {
  cli.command(CLI_COMMANDS.environmentExport, {
    description:
      "Export an environment manifest and its capture Evidence as an agent environment bundle folder the agentenv framework runs with agent-env run",
    args: z.object({
      manifest: manifestArgument,
      directory: z
        .string()
        .describe(
          "Bundle directory to create; must be absent or empty, nothing is overwritten",
        ),
    }),
    options: z.object({
      evidence: evidenceOption,
      packageTarball: z
        .string()
        .optional()
        .describe(
          "Packed rea-agents tarball (npm pack) copied into the env folder and installed by the Dockerfile instead of the registry package pinned to this version",
        ),
      name: z
        .string()
        .optional()
        .describe(
          "Env folder and env id (kebab-case); default the manifest's name",
        ),
    }),
    run: ({ args, options }) =>
      logCliCommand(logger, CLI_COMMANDS.environmentExport, () =>
        exportEnvironmentCommand({
          manifest: args.manifest,
          evidence: options.evidence,
          directory: args.directory,
          packageTarball: options.packageTarball,
          name: options.name,
        }),
      ),
  });
};

/** Register the long-running agent environment server command and the bundle export. */
export const registerEnvironmentCommands = (
  cli: CliInstance,
  logger: Logger,
  environment: Readonly<NodeJS.ProcessEnv>,
): void => {
  registerExportCommand(cli, logger);
  registerCompareCommand(cli, logger);
  cli.command(CLI_COMMANDS.environmentServe, {
    description:
      "Serve an environment manifest as an agent environment over streamable HTTP until SIGINT or SIGTERM: read tools, and write tools whose effect the capture confirmed, answer from the state the capture observed, derived at startup, or every tool replays retained capture records with --replay-only or when the state is unavailable",
    args: z.object({ manifest: manifestArgument }),
    options: z.object({
      evidence: evidenceOption,
      replayOnly: z
        .boolean()
        .default(false)
        .describe(
          "Serve pure replay: derive no state, serve every manifest tool from its retained records and answer every /agentenv method as not found",
        ),
      host: z
        .string()
        .min(1)
        .optional()
        .describe("Listener address; default MCP_HOST, else 127.0.0.1"),
      port: mcpHttpListenerPortSchema
        .optional()
        .describe(
          "Listener port; default MCP_PORT, else 0 for an ephemeral port",
        ),
    }),
    run: ({ args, options }) =>
      withCommandCancellation((signal) =>
        logCliCommand(logger, CLI_COMMANDS.environmentServe, () =>
          serveEnvironmentCommand(
            {
              manifest: args.manifest,
              evidence: options.evidence,
              replayOnly: options.replayOnly,
              host: options.host,
              port: options.port,
            },
            environment,
            logger,
            signal,
          ),
        ),
      ),
  });
};