import { CircuitDeviceRowRepository } from "../../db/repositories/circuit-device-row.repository.js";
import { ProjectDeviceRepository } from "../../db/repositories/project-device.repository.js";
import type { ProjectDeviceRowSyncStore } from "../ports/project-device-row-sync.store.js";
import {
  projectDeviceSyncFields,
  type ProjectDeviceSyncField,
} from "../../shared/constants/project-device-sync-fields.js";
import {
  parseOverriddenFields,
  serializeOverriddenFields,
} from "./project-device-overrides.js";

export {
  parseOverriddenFields,
  serializeOverriddenFields,
} from "./project-device-overrides.js";

type ProjectDevice = NonNullable<Awaited<ReturnType<ProjectDeviceRepository["findById"]>>>;
type LinkedRow = Awaited<ReturnType<CircuitDeviceRowRepository["listLinkedByProjectDevice"]>>[number];

type SyncDependencies = {
  projectDeviceRepository: Pick<ProjectDeviceRepository, "findById">;
  deviceRowRepository: Pick<
    CircuitDeviceRowRepository,
    | "listLinkedByProjectDevice"
    | "listLinkStatesByIds"
  >;
  deviceRowSyncStore: ProjectDeviceRowSyncStore;
};

export interface ProjectDeviceSyncRestoreRow {
  rowId: string;
  values: Partial<Record<ProjectDeviceSyncField, string | number | null>>;
  overriddenFields: ProjectDeviceSyncField[];
}

function sourceValue(projectDevice: ProjectDevice, field: ProjectDeviceSyncField) {
  return projectDevice[field];
}

function valuesEqual(left: unknown, right: unknown) {
  return (left ?? null) === (right ?? null);
}

function buildDifferences(projectDevice: ProjectDevice, row: LinkedRow) {
  return projectDeviceSyncFields
    .filter((field) => !valuesEqual(row[field], sourceValue(projectDevice, field)))
    .map((field) => ({
      field,
      currentValue: row[field] ?? null,
      sourceValue: sourceValue(projectDevice, field) ?? null,
      isOverridden: parseOverriddenFields(row.overriddenFields).includes(field),
    }));
}

export class ProjectDeviceSyncService {
  private readonly projectDeviceRepository: SyncDependencies["projectDeviceRepository"];
  private readonly deviceRowRepository: SyncDependencies["deviceRowRepository"];
  private readonly deviceRowSyncStore?: SyncDependencies["deviceRowSyncStore"];

  constructor(deps?: Partial<SyncDependencies>) {
    this.projectDeviceRepository = deps?.projectDeviceRepository ?? new ProjectDeviceRepository();
    this.deviceRowRepository = deps?.deviceRowRepository ?? new CircuitDeviceRowRepository();
    this.deviceRowSyncStore = deps?.deviceRowSyncStore;
  }

  private getDeviceRowSyncStore() {
    if (!this.deviceRowSyncStore) {
      throw new Error("Project-device row synchronization is not configured.");
    }
    return this.deviceRowSyncStore;
  }

  async getPreview(projectId: string, projectDeviceId: string) {
    const projectDevice = await this.projectDeviceRepository.findById(projectId, projectDeviceId);
    if (!projectDevice) {
      throw new Error("Project device not found.");
    }
    const rows = await this.deviceRowRepository.listLinkedByProjectDevice(projectId, projectDeviceId);

    return {
      projectDevice: {
        id: projectDevice.id,
        name: projectDevice.name,
        displayName: projectDevice.displayName,
      },
      rows: rows.map((row) => ({
        rowId: row.id,
        circuitId: row.circuitId,
        equipmentIdentifier: row.equipmentIdentifier,
        circuitDisplayName: row.circuitDisplayName,
        circuitListId: row.circuitListId,
        circuitListName: row.circuitListName,
        distributionBoardId: row.distributionBoardId,
        distributionBoardName: row.distributionBoardName,
        rowDisplayName: row.displayName,
        overriddenFields: parseOverriddenFields(row.overriddenFields),
        differences: buildDifferences(projectDevice, row),
      })),
    };
  }

  async synchronize(
    projectId: string,
    projectDeviceId: string,
    rowIds: string[],
    fields: ProjectDeviceSyncField[]
  ) {
    const projectDevice = await this.projectDeviceRepository.findById(projectId, projectDeviceId);
    if (!projectDevice) {
      throw new Error("Project device not found.");
    }
    const linkedRows = await this.deviceRowRepository.listLinkedByProjectDevice(projectId, projectDeviceId);
    const selectedRows = this.resolveSelectedRows(linkedRows, rowIds);
    const selectedFields = [...new Set(fields)];
    const undoRows: ProjectDeviceSyncRestoreRow[] = selectedRows.map((row) => ({
      rowId: row.id,
      values: Object.fromEntries(selectedFields.map((field) => [field, row[field] ?? null])),
      overriddenFields: parseOverriddenFields(row.overriddenFields),
    }));

    const changes = [];
    for (const row of selectedRows) {
      const next = this.copyRow(row);
      for (const field of selectedFields) {
        Object.assign(next, { [field]: sourceValue(projectDevice, field) ?? undefined });
      }
      const remainingOverrides = parseOverriddenFields(row.overriddenFields).filter(
        (field) => !selectedFields.includes(field)
      );
      next.overriddenFields = serializeOverriddenFields(remainingOverrides);
      changes.push({ rowId: row.id, input: next });
    }
    this.getDeviceRowSyncStore().updateLinkedRows(projectDeviceId, changes);

    return {
      preview: await this.getPreview(projectId, projectDeviceId),
      undo: { rows: undoRows },
    };
  }

  async disconnect(projectId: string, projectDeviceId: string, rowIds: string[]) {
    const linkedRows = await this.deviceRowRepository.listLinkedByProjectDevice(projectId, projectDeviceId);
    const selectedRows = this.resolveSelectedRows(linkedRows, rowIds);
    const disconnectedRowIds = selectedRows.map((row) => row.id);

    this.getDeviceRowSyncStore().disconnectLinkedRows(
      projectDeviceId,
      disconnectedRowIds
    );

    return { disconnectedRowIds, undo: { rowIds: disconnectedRowIds } };
  }

  async restore(
    projectId: string,
    projectDeviceId: string,
    restoreRows: ProjectDeviceSyncRestoreRow[]
  ) {
    const linkedRows = await this.deviceRowRepository.listLinkedByProjectDevice(projectId, projectDeviceId);
    const selectedRows = this.resolveSelectedRows(linkedRows, restoreRows.map((row) => row.rowId));
    const restoreById = new Map(restoreRows.map((row) => [row.rowId, row]));
    const changes = selectedRows.map((row) => {
      const restore = restoreById.get(row.id)!;
      const next = this.copyRow(row);
      for (const [field, value] of Object.entries(restore.values) as Array<
        [ProjectDeviceSyncField, string | number | null]
      >) {
        Object.assign(next, { [field]: value ?? undefined });
      }
      next.overriddenFields = serializeOverriddenFields(restore.overriddenFields);
      return { rowId: row.id, input: next };
    });

    this.getDeviceRowSyncStore().updateLinkedRows(projectDeviceId, changes);
    return this.getPreview(projectId, projectDeviceId);
  }

  async reconnect(projectId: string, projectDeviceId: string, rowIds: string[]) {
    const projectDevice = await this.projectDeviceRepository.findById(projectId, projectDeviceId);
    if (!projectDevice) {
      throw new Error("Project device not found.");
    }
    const uniqueRowIds = [...new Set(rowIds)];
    const linkStates = await this.deviceRowRepository.listLinkStatesByIds(projectId, uniqueRowIds);
    if (linkStates.length !== uniqueRowIds.length || linkStates.some((row) => row.linkedProjectDeviceId !== null)) {
      throw new Error("One or more rows cannot be reconnected.");
    }
    this.getDeviceRowSyncStore().reconnectRows(projectDeviceId, uniqueRowIds);
    return this.getPreview(projectId, projectDeviceId);
  }

  private resolveSelectedRows(linkedRows: LinkedRow[], rowIds: string[]) {
    const uniqueRowIds = [...new Set(rowIds)];
    const byId = new Map(linkedRows.map((row) => [row.id, row]));
    const selectedRows = uniqueRowIds.map((rowId) => byId.get(rowId)).filter(Boolean) as LinkedRow[];
    if (selectedRows.length !== uniqueRowIds.length) {
      throw new Error("One or more rows are not linked to this project device.");
    }
    return selectedRows;
  }

  private copyRow(row: LinkedRow) {
    return {
      linkedProjectDeviceId: row.linkedProjectDeviceId ?? undefined,
      name: row.name,
      displayName: row.displayName,
      phaseType: row.phaseType ?? undefined,
      connectionKind: row.connectionKind ?? undefined,
      costGroup: row.costGroup ?? undefined,
      category: row.category ?? undefined,
      level: row.level ?? undefined,
      roomId: row.roomId ?? undefined,
      roomNumberSnapshot: row.roomNumberSnapshot ?? undefined,
      roomNameSnapshot: row.roomNameSnapshot ?? undefined,
      quantity: row.quantity,
      powerPerUnit: row.powerPerUnit,
      simultaneityFactor: row.simultaneityFactor,
      cosPhi: row.cosPhi ?? undefined,
      remark: row.remark ?? undefined,
      overriddenFields: row.overriddenFields ?? undefined,
    };
  }
}