import type {
  AcquisitionSlot,
  AcquisitionSlotCreate,
  SlotStatus as ContractSlotStatus,
  JsonObject,
} from "@umt/contracts";
import type {
  SlotStatus as DomainSlotStatus,
  SlotCompletionSpec,
  SlotEvaluation,
  SlotHardConditions,
  SlotSoftPreferences,
  SlotSpec,
  SlotUpgradePolicy,
} from "@umt/domain";

// Slot:状态两侧取值相同(REQ §6.1),映射表只为让任一侧增删值时编译/测试失败。
// 规则 JSON 列(hard_conditions / soft_preferences / upgrade_threshold / completion / fallback)↔ domain SlotSpec。

export type { DomainSlotStatus };

const TO_CONTRACT: Record<DomainSlotStatus, ContractSlotStatus> = {
  empty: "empty",
  reserved: "reserved",
  downloading: "downloading",
  verifying: "verifying",
  satisfied: "satisfied",
  attention: "attention",
  upgrade_pending: "upgrade_pending",
};
const TO_DOMAIN: Record<ContractSlotStatus, DomainSlotStatus> = {
  empty: "empty",
  reserved: "reserved",
  downloading: "downloading",
  verifying: "verifying",
  satisfied: "satisfied",
  upgrade_pending: "upgrade_pending",
  attention: "attention",
};

export const DOMAIN_SLOT_STATUSES = Object.keys(TO_CONTRACT) as DomainSlotStatus[];

export const toContractSlotStatus = (s: DomainSlotStatus): ContractSlotStatus => TO_CONTRACT[s];
export const toDomainSlotStatus = (s: ContractSlotStatus): DomainSlotStatus => TO_DOMAIN[s];

type SlotRuleRow = Pick<
  AcquisitionSlot,
  "id" | "name" | "hardConditions" | "softPreferences" | "upgradeThreshold" | "completion" | "fallback"
>;

const isEmpty = (o: JsonObject | null | undefined) => !o || Object.keys(o).length === 0;

/**
 * acquisition_slot 行 → domain SlotSpec。JSON 列按 domain 类型原样解释(写入时由 slotSpecToColumns 保证形状);
 * fallback.unknownPolicy 对应 SlotSpec.unknownPolicy。
 */
export function slotSpecFromRow(row: SlotRuleRow): SlotSpec {
  const unknownPolicy = row.fallback.unknownPolicy as SlotSpec["unknownPolicy"] | undefined;
  return {
    id: row.id,
    name: row.name,
    hard: row.hardConditions as SlotHardConditions,
    ...(unknownPolicy !== undefined ? { unknownPolicy } : {}),
    ...(isEmpty(row.softPreferences) ? {} : { soft: row.softPreferences as SlotSoftPreferences }),
    ...(isEmpty(row.upgradeThreshold) ? {} : { upgrade: row.upgradeThreshold as unknown as SlotUpgradePolicy }),
    ...(isEmpty(row.completion) ? {} : { completion: row.completion as unknown as SlotCompletionSpec }),
  };
}

/** domain SlotSpec → acquisition_slot 规则列(Create/Update 可直接展开) */
export function slotSpecToColumns(
  spec: SlotSpec,
): Pick<
  AcquisitionSlotCreate,
  "name" | "hardConditions" | "softPreferences" | "upgradeThreshold" | "completion" | "fallback"
> {
  const json = (v: unknown): JsonObject => (v ? (JSON.parse(JSON.stringify(v)) as JsonObject) : {});
  return {
    name: spec.name,
    hardConditions: json(spec.hard),
    softPreferences: json(spec.soft),
    upgradeThreshold: json(spec.upgrade),
    completion: json(spec.completion),
    fallback: spec.unknownPolicy === undefined ? {} : json({ unknownPolicy: spec.unknownPolicy }),
  };
}

export interface ContractSlotEvaluation {
  decision: SlotEvaluation["decision"];
  /** 可以用这个候选生成计划(accept 或 upgrade) */
  acceptable: boolean;
  /** 与 DownloadPlanOutput.rejected 同形:硬条件不满足 / 字段未知的原因 */
  rejected: { code: string; message: string }[];
  reasons: string[];
}

/** domain 评估结果 → 能力输出/决策记录用的扁平表示 */
export function toContractSlotEvaluation(ev: SlotEvaluation): ContractSlotEvaluation {
  switch (ev.decision) {
    case "accept":
    case "upgrade":
      return { decision: ev.decision, acceptable: true, rejected: [], reasons: [...ev.reasons] };
    case "reject":
      return {
        decision: "reject",
        acceptable: false,
        rejected: ev.violations.map((v) => ({
          code: `${v.field}.${v.code}`,
          message:
            v.expected === undefined
              ? `${v.field}: ${v.code}`
              : `${v.field}: ${v.code}(期望 ${JSON.stringify(v.expected)},实际 ${JSON.stringify(v.actual ?? null)})`,
        })),
        reasons: [],
      };
    case "unknown_field":
      return {
        decision: "unknown_field",
        acceptable: false,
        rejected: ev.missing.map((m) => ({ code: `unknown_field.${m}`, message: `字段未知,需要补充: ${m}` })),
        reasons: [],
      };
  }
}