import { z } from "zod";
import { samePersistedDynamicReceipt } from "./birth-time-dynamic-action-replay.ts";
import { toPublicDynamicChoiceQuestion } from "./birth-time-dynamic-choice-internal.ts";
import {
  dynamicJourneyTurnStateSchema,
} from "./birth-time-journey-turn-protocol.ts";
import type { DynamicJourneyTurnState } from "./birth-time-journey-turn-protocol.ts";
import type {
  DynamicScoringJobCommand,
  DynamicScoringJobFailureCommand,
  DynamicCandidateConfirmationCommand,
  DynamicStoredRectificationCase,
  LegacyStoredRectificationCase,
  StoredRectificationCase,
} from "./birth-time-journey-service.ts";
import {
  dynamicPrivateStateSchema,
  isTerminalLegacyCase,
  prepareLegacyDynamicUpgrade,
} from "./birth-time-journey-dynamic-state.ts";
import type { DynamicPrivateJourneyState } from "./birth-time-journey-dynamic-state.ts";
import {
  BirthTimeJourneyStoreError,
  StaleJourneyTurnError,
} from "./birth-time-journey-store-errors.ts";

export { BirthTimeDynamicStateMissingError } from "./birth-time-journey-dynamic-state.ts";

const actionIdSchema = z.string().uuid();
const rpcVersionSchema = z.number().int().nonnegative();
type RpcError = { readonly message: string };
type RpcResult = { readonly data: unknown; readonly error: RpcError | null };
export type DynamicRpcClient = {
  readonly rpc: (
    name: string,
    args: Readonly<Record<string, unknown>>,
  ) => PromiseLike<RpcResult>;
};

function publicTurn(
  value: DynamicStoredRectificationCase,
  turnVersion: number,
): DynamicJourneyTurnState {
  const currentQuestion = value.currentChoiceQuestion;
  if (value.dynamicTurnState.nextAction.kind === "ask_dynamic_choice") {
    if (currentQuestion === null) throw new BirthTimeJourneyStoreError("update_case");
    return dynamicJourneyTurnStateSchema.parse({
      ...value.dynamicTurnState,
      turnVersion,
      nextAction: {
        kind: "ask_dynamic_choice",
        question: toPublicDynamicChoiceQuestion(currentQuestion),
      },
    });
  }
  return dynamicJourneyTurnStateSchema.parse({
    ...value.dynamicTurnState,
    turnVersion,
  });
}

function privateState(value: DynamicStoredRectificationCase): DynamicPrivateJourneyState {
  return dynamicPrivateStateSchema.parse({
    candidateModel: value.candidateModel,
    currentChoiceQuestion: value.currentChoiceQuestion,
    choiceAnswers: value.choiceAnswers,
    choiceEvidence: value.choiceEvidence,
    dynamicControl: value.dynamicControl,
    agentContext: value.agentContext,
  });
}

function isStaleRpc(error: RpcError): boolean {
  return error.message.includes("stale_birth_time_dynamic_turn")
    || error.message.includes("stale_birth_time_dynamic_scoring_job")
    || error.message.includes("stale_birth_time_dynamic_candidate")
    || error.message.includes("birth_time_dynamic_candidate_invalid")
    || error.message.includes("stale_birth_time_legacy_upgrade");
}

export function createDynamicTurnPersistence(
  client: DynamicRpcClient,
  loadCase: (userId: string, caseId: string) => Promise<StoredRectificationCase | null>,
  asOfDate: () => string,
) {
  async function loadedDynamic(userId: string, caseId: string): Promise<DynamicStoredRectificationCase> {
    const loaded = await loadCase(userId, caseId);
    if (!loaded || loaded.journeyProtocol !== "dynamic-choice-v2") {
      throw new BirthTimeJourneyStoreError("load_case");
    }
    return loaded;
  }

  async function savedDynamicScoring(
    value: DynamicStoredRectificationCase,
    expectedVersion: number,
    result: RpcResult,
  ): Promise<DynamicStoredRectificationCase> {
    if (result.error) {
      if (isStaleRpc(result.error)) {
        const current = await loadCase(value.userId, value.id);
        throw new StaleJourneyTurnError(
          value.id,
          expectedVersion,
          current?.turnVersion ?? 0,
        );
      }
      throw new BirthTimeJourneyStoreError("update_case");
    }
    const version = rpcVersionSchema.safeParse(result.data);
    if (!version.success || version.data !== expectedVersion + 1) {
      throw new BirthTimeJourneyStoreError("update_case");
    }
    const loaded = await loadedDynamic(value.userId, value.id);
    if (
      loaded.turnVersion !== version.data
      || loaded.dynamicTurnState.turnVersion !== version.data
    ) throw new BirthTimeJourneyStoreError("load_case");
    return loaded;
  }

  function scoringIdentity(command: DynamicScoringJobCommand) {
    return {
      p_job_id: command.jobId,
      p_expected_version: command.expectedVersion,
      p_evidence_fingerprint: command.evidenceFingerprint,
      p_algorithm_version: command.algorithmVersion,
    };
  }

  return {
    async confirmDynamicCandidate(
      value: DynamicStoredRectificationCase,
      command: DynamicCandidateConfirmationCommand,
    ): Promise<DynamicStoredRectificationCase> {
      const receipt = actionIdSchema.parse(command.actionId).toLowerCase();
      const result = await client.rpc("confirm_birth_time_dynamic_candidate", {
        p_user_id: value.userId,
        p_case_id: value.id,
        p_result_id: command.resultId,
        p_time: command.time,
        p_action_id: receipt,
        p_expected_version: command.expectedVersion,
        p_snapshot: value.snapshot,
        p_turn_state: publicTurn(value, command.expectedVersion + 1),
      });
      const current = await loadCase(value.userId, value.id);
      if (result.error) {
        if (current?.journeyProtocol === "dynamic-choice-v2"
          && current.processedActionIds.includes(receipt)
          && samePersistedDynamicReceipt(value, current, receipt, command.expectedVersion)) {
          return current;
        }
        if (isStaleRpc(result.error)) {
          throw new StaleJourneyTurnError(value.id, command.expectedVersion, current?.turnVersion ?? 0);
        }
        throw new BirthTimeJourneyStoreError("update_case");
      }
      const version = rpcVersionSchema.safeParse(result.data);
      if (!current || current.journeyProtocol !== "dynamic-choice-v2") {
        throw new BirthTimeJourneyStoreError("load_case");
      }
      if (!version.success || version.data !== command.expectedVersion + 1
        || !current.processedActionIds.includes(receipt)
        || !samePersistedDynamicReceipt(value, current, receipt, command.expectedVersion)) {
        throw new StaleJourneyTurnError(value.id, command.expectedVersion, current.turnVersion);
      }
      return current;
    },

    async saveDynamicTurn(
      value: DynamicStoredRectificationCase,
      expectedVersion: number,
      actionId: string,
    ): Promise<DynamicStoredRectificationCase> {
      const receipt = actionIdSchema.parse(actionId).toLowerCase();
      const result = await client.rpc("save_birth_time_dynamic_turn", {
        p_user_id: value.userId,
        p_case_id: value.id,
        p_expected_version: expectedVersion,
        p_action_id: receipt,
        p_public_turn_state: publicTurn(value, expectedVersion + 1),
        p_snapshot: value.snapshot,
        p_candidate_result: value.candidateResult ?? {},
        p_private_state: privateState(value),
      });
      if (result.error) {
        const current = await loadCase(value.userId, value.id);
        if (current?.journeyProtocol === "dynamic-choice-v2"
          && current.processedActionIds.includes(receipt)) {
          if (samePersistedDynamicReceipt(value, current, receipt, expectedVersion)) return current;
          throw new StaleJourneyTurnError(value.id, expectedVersion, current.turnVersion);
        }
        if (isStaleRpc(result.error)) {
          throw new StaleJourneyTurnError(
            value.id,
            expectedVersion,
            current?.turnVersion ?? 0,
          );
        }
        throw new BirthTimeJourneyStoreError("update_case");
      }
      const version = rpcVersionSchema.parse(result.data);
      const current = await loadedDynamic(value.userId, value.id);
      if (version !== expectedVersion + 1
        || !current.processedActionIds.includes(receipt)
        || !samePersistedDynamicReceipt(value, current, receipt, expectedVersion)) {
        throw new StaleJourneyTurnError(value.id, expectedVersion, current.turnVersion);
      }
      return current;
    },

    async completeDynamicScoringJob(
      value: DynamicStoredRectificationCase,
      command: DynamicScoringJobCommand,
    ): Promise<DynamicStoredRectificationCase> {
      if (!value.candidateResult) throw new BirthTimeJourneyStoreError("update_case");
      const result = await client.rpc("complete_birth_time_dynamic_scoring_job", {
        p_user_id: value.userId,
        p_case_id: value.id,
        ...scoringIdentity(command),
        p_public_turn_state: publicTurn(value, command.expectedVersion + 1),
        p_snapshot: value.snapshot,
        p_candidate_result: value.candidateResult,
        p_private_state: privateState(value),
      });
      return savedDynamicScoring(value, command.expectedVersion, result);
    },

    async failDynamicScoringJob(
      value: DynamicStoredRectificationCase,
      command: DynamicScoringJobFailureCommand,
    ): Promise<DynamicStoredRectificationCase> {
      const result = await client.rpc("fail_birth_time_dynamic_scoring_job", {
        p_user_id: value.userId,
        p_case_id: value.id,
        ...scoringIdentity(command),
        p_failure_code: command.failureCode,
        p_public_turn_state: publicTurn(value, command.expectedVersion + 1),
        p_private_state: privateState(value),
      });
      return savedDynamicScoring(value, command.expectedVersion, result);
    },

    async upgradeLegacyActiveCase(
      value: LegacyStoredRectificationCase,
    ): Promise<StoredRectificationCase> {
      if (isTerminalLegacyCase(value)) return value;
      const upgraded = prepareLegacyDynamicUpgrade(value, asOfDate());
      const result = await client.rpc("upgrade_birth_time_legacy_case", {
        p_user_id: value.userId,
        p_case_id: value.id,
        p_expected_version: value.turnVersion ?? 0,
        p_public_turn_state: upgraded.dynamicTurnState,
        p_private_state: privateState(upgraded),
      });
      if (result.error) {
        if (isStaleRpc(result.error)) {
          const current = await loadCase(value.userId, value.id);
          throw new StaleJourneyTurnError(
            value.id,
            value.turnVersion ?? 0,
            current?.turnVersion ?? 0,
          );
        }
        throw new BirthTimeJourneyStoreError("update_case");
      }
      rpcVersionSchema.parse(result.data);
      return loadedDynamic(value.userId, value.id);
    },
  };
}