import { API_PATHS } from "@/api/api-paths";
import { apiGet } from "@/api/api";
import { handleApiResponse } from "@/api/handle-api-response";
import type { Options } from "ky";
import type { DashboardRangeParams } from "@/domain/dashboard/types/dashboard-range";
import type {
  DashboardBreakdownRow,
  DashboardStats,
  DashboardStatusBucketRow,
} from "@/domain/dashboard/types/dashboard-stats";
import type { DispatcherPerformanceRow } from "@/domain/dashboard/types/dashboard-performance";
import {
  DISPATCHER_PAGE_SIZE,
  type DispatcherPage,
} from "@/domain/dashboard/types/dashboard-dispatcher-page";
import type { DashboardTrendParams } from "@/domain/dashboard/types/dashboard-trend";
import type {
  DashboardTrend,
  DashboardTrendGranularity,
} from "@/domain/dashboard/types/dashboard-trend";
import {
  UNMAPPED_REGION_LABEL,
  type RegionWorkOrdersRow,
} from "@/domain/dashboard/types/dashboard-regions";
import type { DispatcherWorkloadRow } from "@/domain/dashboard/types/dashboard-workload";
import type { VendorInsightRow } from "@/domain/dashboard/types/dashboard-vendor-insights";
import { WO_TYPES } from "@/domain/work-orders/types/work-order-wizard";

function toNumber(value: unknown): number {
  if (typeof value === "number" && Number.isFinite(value)) {
    return value;
  }

  if (typeof value === "string" && value.trim() !== "") {
    const parsed = Number(value);
    return Number.isFinite(parsed) ? parsed : 0;
  }

  return 0;
}

function asString(value: unknown): string {
  if (typeof value === "string") {
    return value.trim();
  }

  if (typeof value === "number" && Number.isFinite(value)) {
    return String(value);
  }

  return "";
}

function asRecords(value: unknown): Record<string, unknown>[] {
  if (!Array.isArray(value)) {
    return [];
  }

  return value.filter(
    (item): item is Record<string, unknown> =>
      typeof item === "object" && item !== null && !Array.isArray(item),
  );
}

function readField(data: Record<string, unknown>, key: string): unknown {
  const capitalized = key.charAt(0).toUpperCase() + key.slice(1);
  const value = data[key] ?? data[capitalized];
  return value === null ? undefined : value;
}

function toRecord(value: unknown): Record<string, unknown> {
  return typeof value === "object" && value !== null && !Array.isArray(value)
    ? (value as Record<string, unknown>)
    : {};
}

function readCollection(value: unknown, key: string): Record<string, unknown>[] {
  const data = toRecord(value);
  const collection = key ? (readField(data, key) ?? value) : value;
  return asRecords(collection);
}

/**
 * Stats, Regions, Workload, and Performance share `DashboardStatsQueryDTO`
 * (backend#145): the range dates ride along when present, and `dispatcherId`
 * scopes the read to a single dispatcher (SH-336's picker — All sends nothing,
 * My WOs / an individual sends that id). Vendor Insights and Trend take no such
 * param and stay company-wide (SH-349).
 */
function scopedSearchParams(
  range?: DashboardRangeParams,
  dispatcherId?: string,
): Options | undefined {
  const searchParams: Record<string, string> = {};
  if (range?.dateFrom && range?.dateTo) {
    searchParams.dateFrom = range.dateFrom;
    searchParams.dateTo = range.dateTo;
  }
  if (dispatcherId) {
    searchParams.dispatcherId = dispatcherId;
  }
  return Object.keys(searchParams).length > 0 ? { searchParams } : undefined;
}

/**
 * Workload and Performance are paged server-side (backend#126/#127): `page` is
 * 1-based and always sent, the range dates ride along when present, and
 * `dispatcherId` scopes to a single dispatcher (SH-336).
 */
function dispatcherPageSearchParams(
  range: DashboardRangeParams | undefined,
  page: number,
  dispatcherId?: string,
): Options {
  const searchParams: Record<string, string | number> = { page };
  if (range?.dateFrom && range?.dateTo) {
    searchParams.dateFrom = range.dateFrom;
    searchParams.dateTo = range.dateTo;
  }
  if (dispatcherId) {
    searchParams.dispatcherId = dispatcherId;
  }
  return { searchParams };
}

/**
 * Reads the paging envelope the dispatcher endpoints return (`Page`, `PageSize`,
 * `TotalDispatchers`). Falls back to the requested page, the default page size,
 * and the item count for the legacy bare-array shape so older responses still
 * render (with the pager hidden).
 */
function readDispatcherPageMeta(
  raw: unknown,
  requestedPage: number,
  itemCount: number,
): { page: number; pageSize: number; totalDispatchers: number } {
  const data = toRecord(raw);
  const pageValue = readField(data, "page");
  const pageSizeValue = readField(data, "pageSize");
  const totalValue = readField(data, "totalDispatchers");
  return {
    page: pageValue == null ? requestedPage : toNumber(pageValue),
    pageSize: pageSizeValue == null ? DISPATCHER_PAGE_SIZE : toNumber(pageSizeValue),
    totalDispatchers: totalValue == null ? itemCount : toNumber(totalValue),
  };
}

function trendSearchParams(params?: DashboardTrendParams): Options | undefined {
  if (
    !params ||
    (!params.dateFrom && !params.dateTo && !params.granularity && !params.range && !params.year)
  ) {
    return undefined;
  }

  const searchParams: Record<string, string | number> = {};
  if (params.dateFrom) searchParams.dateFrom = params.dateFrom;
  if (params.dateTo) searchParams.dateTo = params.dateTo;
  if (params.granularity) searchParams.granularity = params.granularity;
  if (params.range) searchParams.range = params.range;
  if (params.year) searchParams.year = params.year;

  return { searchParams };
}

const BREAKDOWN_TYPE_BY_LOWER = new Map<string, string>(
  WO_TYPES.map((type) => [type.toLowerCase(), type]),
);

/**
 * The backend breakdown object (backend#138) serializes its keys with no
 * JsonPropertyName, so `PM`/`Emergency`/`Reactive`/`Overdue`/`Other` arrive
 * lowercase. The card uses the row label as both display text and the
 * `types` drill-down id, and `workOrderTypeDrilldownSearch` only accepts
 * canonical `WOType` values — so map lowercase type keys back to their
 * canonical labels. `other` is not a WOType: keep it as a labelled,
 * non-drillable "Other" row. Unknown values (e.g. lifecycle labels from the
 * legacy array shape) pass through unchanged.
 */
function normalizeBreakdownStatus(raw: string): string {
  const trimmed = raw.trim();
  const canonical = BREAKDOWN_TYPE_BY_LOWER.get(trimmed.toLowerCase());
  if (canonical) return canonical;
  if (trimmed.toLowerCase() === "other") return "Other";
  return trimmed;
}

function mapBreakdownRow(raw: Record<string, unknown>): DashboardBreakdownRow {
  const status = asString(
    readField(raw, "status") ?? readField(raw, "name") ?? readField(raw, "label"),
  );
  return {
    status: status ? normalizeBreakdownStatus(status) : UNMAPPED_REGION_LABEL,
    count: toNumber(readField(raw, "count") ?? readField(raw, "value")),
  };
}

function mapBreakdown(value: unknown): DashboardBreakdownRow[] {
  if (Array.isArray(value)) {
    return asRecords(value).map(mapBreakdownRow);
  }

  if (typeof value === "object" && value !== null) {
    return Object.entries(value as Record<string, unknown>)
      .map(([status, count]) => ({
        status: normalizeBreakdownStatus(status),
        count: toNumber(count),
      }))
      .filter((row) => row.status !== "");
  }

  return [];
}

function mapDispatcherIdentity(raw: Record<string, unknown>): {
  dispatcherId: string;
  dispatcherName: string;
} {
  return {
    dispatcherId: asString(
      readField(raw, "dispatcherId") ?? readField(raw, "id") ?? readField(raw, "userId"),
    ),
    dispatcherName: asString(readField(raw, "dispatcherName") ?? readField(raw, "name")),
  };
}

function mapStatusDistribution(value: unknown): DashboardStatusBucketRow[] {
  return asRecords(value)
    .map((row) => ({
      status: asString(
        readField(row, "status") ?? readField(row, "name") ?? readField(row, "label"),
      ),
      count: toNumber(readField(row, "count") ?? readField(row, "value")),
    }))
    .filter((row) => row.status !== "");
}

function mapDashboardStats(raw: unknown): DashboardStats {
  const data = toRecord(raw);
  const average = readField(data, "averageResolutionDays");

  return {
    total: toNumber(readField(data, "total")),
    open: toNumber(readField(data, "open")),
    notDispatched: toNumber(readField(data, "notDispatched")),
    completed: toNumber(readField(data, "completed")),
    dueCount: toNumber(readField(data, "dueCount")),
    completedDueCount: toNumber(readField(data, "completedDueCount")),
    completionRate: toNumber(readField(data, "completionRate")),
    averageResolutionDays: average == null ? null : toNumber(average),
    scheduledTomorrow: toNumber(readField(data, "scheduledTomorrow")),
    pendingUplifts: toNumber(readField(data, "pendingUplifts")),
    avetaPending: toNumber(readField(data, "avetaPending")),
    breakdown: mapBreakdown(readField(data, "breakdown") ?? readField(data, "workOrderBreakdown")),
    statusDistribution: mapStatusDistribution(readField(data, "statusDistribution")),
  };
}

function mapDispatcherWorkload(raw: unknown): DispatcherWorkloadRow[] {
  return readCollection(raw, "items").map((rawRow) => {
    const identity = mapDispatcherIdentity(rawRow);
    return {
      ...identity,
      openWorkOrders: toNumber(
        readField(rawRow, "openWorkOrders") ??
          readField(rawRow, "openCount") ??
          readField(rawRow, "open"),
      ),
      totalWorkOrders: toNumber(
        readField(rawRow, "totalWorkOrders") ??
          readField(rawRow, "totalCount") ??
          readField(rawRow, "scheduledWorkOrders") ??
          readField(rawRow, "scheduled"),
      ),
    };
  });
}

function mapDispatcherPerformance(raw: unknown): DispatcherPerformanceRow[] {
  return readCollection(raw, "items").map((rawRow) => {
    const identity = mapDispatcherIdentity(rawRow);
    return {
      ...identity,
      completionRate: toNumber(
        readField(rawRow, "completionRate") ?? readField(rawRow, "onTimeRate"),
      ),
      averageResolutionDays:
        readField(rawRow, "averageResolutionDays") == null
          ? null
          : toNumber(readField(rawRow, "averageResolutionDays")),
      assignedCount: toNumber(readField(rawRow, "assignedCount") ?? readField(rawRow, "assigned")),
      completedCount: toNumber(
        readField(rawRow, "completedCount") ?? readField(rawRow, "completed"),
      ),
    };
  });
}

function mapRegions(raw: unknown): RegionWorkOrdersRow[] {
  return readCollection(raw, "items").map((rawRow) => {
    const region =
      asString(readField(rawRow, "region") ?? readField(rawRow, "name")) || UNMAPPED_REGION_LABEL;
    return {
      region,
      workOrderCount: toNumber(
        readField(rawRow, "workOrderCount") ??
          readField(rawRow, "count") ??
          readField(rawRow, "total"),
      ),
    };
  });
}

function mapVendorInsights(raw: unknown): VendorInsightRow[] {
  return readCollection(raw, "items").map((rawRow) => ({
    vendorId: asString(
      readField(rawRow, "vendorId") ??
        readField(rawRow, "vendorCompanyId") ??
        readField(rawRow, "id"),
    ),
    vendorName: asString(
      readField(rawRow, "vendorName") ??
        readField(rawRow, "vendorCompanyName") ??
        readField(rawRow, "companyName") ??
        readField(rawRow, "name"),
    ),
    completionRate: toNumber(readField(rawRow, "completionRate")),
    rescheduleRate: toNumber(readField(rawRow, "rescheduleRate")),
    averageResolutionDays:
      readField(rawRow, "averageResolutionDays") == null
        ? null
        : toNumber(readField(rawRow, "averageResolutionDays")),
    totalJobs: toNumber(readField(rawRow, "totalJobs")),
  }));
}

function mapTrendGranularity(value: unknown): DashboardTrendGranularity | null {
  const granularity = asString(value).toLowerCase();
  return granularity === "day" || granularity === "week" || granularity === "month"
    ? granularity
    : null;
}

function mapDashboardTrend(raw: unknown): DashboardTrend {
  const data = toRecord(raw);
  const buckets = readCollection(data, "buckets");
  const legacyPoints = readCollection(data, "points");
  const points = (buckets.length > 0 ? buckets : legacyPoints).map((rawPoint) => ({
    date: asString(readField(rawPoint, "date")),
    label: asString(
      readField(rawPoint, "label") ?? readField(rawPoint, "period") ?? readField(rawPoint, "date"),
    ),
    total: toNumber(
      readField(rawPoint, "total") ?? readField(rawPoint, "count") ?? readField(rawPoint, "value"),
    ),
    open: toNumber(readField(rawPoint, "open")),
    completed: toNumber(readField(rawPoint, "completed")),
    canceled: toNumber(readField(rawPoint, "canceled")),
    overdue: toNumber(readField(rawPoint, "overdue")),
    isCurrent: readField(rawPoint, "isCurrent") === true,
  }));

  return { granularity: mapTrendGranularity(readField(data, "granularity")), points };
}

export const dashboardApi = {
  getStats: async (
    range?: DashboardRangeParams,
    dispatcherId?: string,
  ): Promise<DashboardStats> => {
    const data = await apiGet<unknown>(
      API_PATHS.dashboard.stats,
      scopedSearchParams(range, dispatcherId),
    );
    return mapDashboardStats(handleApiResponse<unknown>(data));
  },
  getWorkload: async (
    range?: DashboardRangeParams,
    page = 1,
    dispatcherId?: string,
  ): Promise<DispatcherPage<DispatcherWorkloadRow>> => {
    const data = await apiGet<unknown>(
      API_PATHS.dashboard.workload,
      dispatcherPageSearchParams(range, page, dispatcherId),
    );
    const response = handleApiResponse<unknown>(data);
    const items = mapDispatcherWorkload(response);
    return { items, ...readDispatcherPageMeta(response, page, items.length) };
  },
  getPerformance: async (
    range?: DashboardRangeParams,
    page = 1,
    dispatcherId?: string,
  ): Promise<DispatcherPage<DispatcherPerformanceRow>> => {
    const data = await apiGet<unknown>(
      API_PATHS.dashboard.performance,
      dispatcherPageSearchParams(range, page, dispatcherId),
    );
    const response = handleApiResponse<unknown>(data);
    const items = mapDispatcherPerformance(response);
    return { items, ...readDispatcherPageMeta(response, page, items.length) };
  },
  getRegions: async (
    range?: DashboardRangeParams,
    dispatcherId?: string,
  ): Promise<RegionWorkOrdersRow[]> => {
    const data = await apiGet<unknown>(
      API_PATHS.dashboard.regions,
      scopedSearchParams(range, dispatcherId),
    );
    return mapRegions(handleApiResponse<unknown>(data));
  },
  getVendorInsights: async (): Promise<VendorInsightRow[]> => {
    const data = await apiGet<unknown>(API_PATHS.dashboard.vendorInsights);
    return mapVendorInsights(handleApiResponse<unknown>(data));
  },
  getTrend: async (params?: DashboardTrendParams): Promise<DashboardTrend> => {
    const data = await apiGet<unknown>(API_PATHS.dashboard.trend, trendSearchParams(params));
    return mapDashboardTrend(handleApiResponse<unknown>(data));
  },
};