Jyotisha/frontend/src/lib/chart-view-load.ts

import { resolveAyanamsa } from "./ayanamsa.ts";
import {
  chartViewMessageSchema,
  type ChartViewResponse,
} from "./chart-view-contract.ts";
import {
  enginePayload,
  logEngineCallFailure,
  type ChartViewLayer,
  type EngineCallResult,
} from "./chart-view-engine.ts";
import { CHART_VIEW_COPY, VARGA_CHIP_ORDER } from "./chart-view-labels.ts";
import {
  buildChartView,
  engineChartHasPlanets,
  type ChartViewProfileInput,
} from "./chart-view-mapper.ts";

export type ChartViewEnginePost = (
  path: string,
  body: Record<string, unknown>,
) => Promise<EngineCallResult>;

export type ChartViewLoadInput = {
  userId: string | null;
  profile: ChartViewProfileInput | null;
  postEngine: ChartViewEnginePost;
  asOf: string;
  rateLimited?: boolean;
  layers?: readonly ChartViewLayer[];
};

function message(
  status: "unauthenticated" | "birth_profile_incomplete" | "chart_unavailable" | "rate_limited",
  copy: string,
): ChartViewResponse {
  return chartViewMessageSchema.parse({ status, billed: false, message: copy });
}

function birthPayload(profile: ChartViewProfileInput): Record<string, unknown> {
  const [year, month, day] = profile.date.split("-").map(Number);
  const [hour, minute] = profile.time.split(":").map(Number);
  return {
    year,
    month,
    day,
    hour,
    minute,
    second: 0,
    lat: profile.latitude,
    lon: profile.longitude,
    tz: profile.timezoneOffset,
    latitude: profile.latitude,
    longitude: profile.longitude,
    timezone: profile.timezoneOffset,
    ayanamsa: resolveAyanamsa({ ayanamsa: profile.ayanamsa }),
    node_mode: "mean",
    house_system: "P",
    skip_vedastro_main_entry_overview: true,
  };
}

function wantedLayers(layers: readonly ChartViewLayer[] | undefined): Set<ChartViewLayer> {
  return new Set(layers ?? []);
}

async function callEngine(
  postEngine: ChartViewEnginePost,
  path: string,
  body: Record<string, unknown>,
): Promise<EngineCallResult> {
  const result = await postEngine(path, body);
  if (result.status !== "ok") logEngineCallFailure(result);
  return result;
}

export async function assembleChartView(input: ChartViewLoadInput): Promise<{
  httpStatus: number;
  body: ChartViewResponse;
}> {
  if (!input.userId) {
    return {
      httpStatus: 401,
      body: message("unauthenticated", CHART_VIEW_COPY.unauthenticated),
    };
  }
  if (input.rateLimited) {
    return {
      httpStatus: 429,
      body: message("rate_limited", CHART_VIEW_COPY.rateLimited),
    };
  }
  const profile = input.profile;
  if (!profile) {
    return {
      httpStatus: 200,
      body: message("birth_profile_incomplete", CHART_VIEW_COPY.incomplete),
    };
  }

  const payload = birthPayload(profile);
  const chartResult = await callEngine(input.postEngine, "/api/chart", payload);
  if (chartResult.status !== "ok") {
    return {
      httpStatus: 200,
      body: message(
        "chart_unavailable",
        chartResult.status === "busy" ? CHART_VIEW_COPY.busy : CHART_VIEW_COPY.unavailable,
      ),
    };
  }
  const chart = chartResult.payload;
  if (chart.success === false || !engineChartHasPlanets(chart)) {
    logEngineCallFailure({
      status: "bad_payload",
      path: "/api/chart",
      elapsedMs: 0,
      errorName: "engine_rejected",
    });
    return {
      httpStatus: 200,
      body: message("chart_unavailable", CHART_VIEW_COPY.unavailable),
    };
  }

  const planets = chart.planets;
  const ascendant = chart.ascendant;
  const houses = chart.houses;
  const followUp = {
    ...payload,
    planets,
    ascendant,
    houses,
  };
  const layers = wantedLayers(input.layers);
  const [varga, chara, western, qizheng] = await Promise.all([
    layers.has("varga")
      ? callEngine(input.postEngine, "/api/varga_full", {
          ...followUp,
          divisions: VARGA_CHIP_ORDER.map((division) => `D${division}`),
        }).then(enginePayload)
      : Promise.resolve(null),
    layers.has("chara")
      ? callEngine(input.postEngine, "/api/dasha/chara", {
          ...followUp,
          antardasha: true,
          mode: "dasha",
        }).then(enginePayload)
      : Promise.resolve(null),
    layers.has("western")
      ? callEngine(input.postEngine, "/api/western", payload).then(enginePayload)
      : Promise.resolve(null),
    layers.has("qizheng")
      ? callEngine(input.postEngine, "/api/qizheng", payload).then(enginePayload)
      : Promise.resolve(null),
  ]);

  try {
    const body = buildChartView({
      chart,
      varga,
      chara,
      western,
      qizheng,
      profile,
      asOf: input.asOf,
    });
    return { httpStatus: 200, body };
  } catch (error) {
    const errorName = error instanceof Error ? error.name : "Error";
    const errorMessage = error instanceof Error ? error.message : "unknown";
    console.warn("chart_view_assemble_failed", { errorName, message: errorMessage });
    return {
      httpStatus: 200,
      body: message("chart_unavailable", CHART_VIEW_COPY.unavailable),
    };
  }
}