import type {
  CompanyFinancialStatementsResponse,
  FinancialUnit,
  RatioRow,
  StandardizedFinancialRow
} from '@/lib/types';
import type { GraphableFinancialSurfaceKind } from '@/lib/financial-metrics';

type GraphingMetricRow = StandardizedFinancialRow | RatioRow;

export type GraphingFetchResult = {
  ticker: string;
  financials?: CompanyFinancialStatementsResponse;
  error?: string;
};

export type GraphingSeriesPoint = {
  periodId: string;
  dateKey: string;
  filingType: '10-K' | '10-Q';
  filingDate: string;
  periodEnd: string | null;
  periodLabel: string;
  value: number | null;
};

export type GraphingCompanySeries = {
  ticker: string;
  companyName: string;
  fiscalPack: string | null;
  status: 'ready' | 'error' | 'no_metric_data' | 'not_meaningful';
  errorMessage: string | null;
  unit: FinancialUnit | null;
  points: GraphingSeriesPoint[];
  latestPoint: GraphingSeriesPoint | null;
  priorPoint: GraphingSeriesPoint | null;
};

export type GraphingLatestValueRow = {
  ticker: string;
  companyName: string;
  fiscalPack: string | null;
  status: GraphingCompanySeries['status'];
  errorMessage: string | null;
  latestValue: number | null;
  priorValue: number | null;
  changeValue: number | null;
  latestDateKey: string | null;
  latestPeriodLabel: string | null;
  latestFilingType: '10-K' | '10-Q' | null;
};

export type GraphingChartDatum = Record<string, unknown> & {
  dateKey: string;
  dateMs: number;
};

type GraphingComparisonData = {
  companies: GraphingCompanySeries[];
  chartData: GraphingChartDatum[];
  latestRows: GraphingLatestValueRow[];
  hasAnyData: boolean;
  hasPartialData: boolean;
};

function sortPeriods(left: { periodEnd: string | null; filingDate: string }, right: { periodEnd: string | null; filingDate: string }) {
  return Date.parse(left.periodEnd ?? left.filingDate) - Date.parse(right.periodEnd ?? right.filingDate);
}

function extractMetricRow(
  financials: CompanyFinancialStatementsResponse,
  surface: GraphableFinancialSurfaceKind,
  metric: string
): GraphingMetricRow | null {
  if (surface === 'ratios') {
    return financials.ratioRows?.find((row) => row.key === metric) ?? null;
  }

  return financials.statementRows?.standardized.find((row) => row.key === metric) ?? null;
}

function extractCompanySeries(
  result: GraphingFetchResult,
  surface: GraphableFinancialSurfaceKind,
  metric: string
): GraphingCompanySeries {
  if (result.error || !result.financials) {
    return {
      ticker: result.ticker,
      companyName: result.ticker,
      fiscalPack: null,
      status: 'error',
      errorMessage: result.error ?? 'Unable to load financial history',
      unit: null,
      points: [],
      latestPoint: null,
      priorPoint: null
    };
  }

  const metricRow = extractMetricRow(result.financials, surface, metric);
  const periods = [...result.financials.periods].sort(sortPeriods);
  const notMeaningful = surface !== 'ratios'
    && metricRow
    && 'resolutionMethod' in metricRow
    && metricRow.resolutionMethod === 'not_meaningful';
  const points = periods.map((period) => ({
    periodId: period.id,
    dateKey: period.periodEnd ?? period.filingDate,
    filingType: period.filingType,
    filingDate: period.filingDate,
    periodEnd: period.periodEnd,
    periodLabel: period.periodLabel,
    value: metricRow?.values[period.id] ?? null
  }));
  const populatedPoints = points.filter((point) => point.value !== null);
  const latestPoint = populatedPoints[populatedPoints.length - 1] ?? null;
  const priorPoint = populatedPoints.length > 1 ? populatedPoints[populatedPoints.length - 2] ?? null : null;

  return {
    ticker: result.financials.company.ticker,
    companyName: result.financials.company.companyName,
    fiscalPack: result.financials.normalization.fiscalPack,
    status: notMeaningful ? 'not_meaningful' : latestPoint ? 'ready' : 'no_metric_data',
    errorMessage: notMeaningful ? 'Not meaningful for this pack.' : latestPoint ? null : 'No data available for the selected metric.',
    unit: metricRow?.unit ?? null,
    points,
    latestPoint,
    priorPoint
  };
}

export function buildGraphingComparisonData(input: {
  results: GraphingFetchResult[];
  surface: GraphableFinancialSurfaceKind;
  metric: string;
}): GraphingComparisonData {
  const companies = input.results.map((result) => extractCompanySeries(result, input.surface, input.metric));
  const chartDatumByDate = new Map<string, GraphingChartDatum>();

  for (const company of companies) {
    for (const point of company.points) {
      const dateMs = Date.parse(point.dateKey);
      const existing = chartDatumByDate.get(point.dateKey) ?? {
        dateKey: point.dateKey,
        dateMs
      };

      existing[company.ticker] = point.value;
      existing[`meta__${company.ticker}`] = point;
      chartDatumByDate.set(point.dateKey, existing);
    }
  }

  const chartData = [...chartDatumByDate.values()]
    .sort((left, right) => left.dateMs - right.dateMs)
    .map((datum) => {
      for (const company of companies) {
        if (!(company.ticker in datum)) {
          datum[company.ticker] = null;
        }
      }

      return datum;
    });

  const latestRows = companies.map((company) => ({
    ticker: company.ticker,
    companyName: company.companyName,
    fiscalPack: company.fiscalPack,
    status: company.status,
    errorMessage: company.errorMessage,
    latestValue: company.latestPoint?.value ?? null,
    priorValue: company.priorPoint?.value ?? null,
    changeValue:
      company.latestPoint?.value !== null
      && company.latestPoint?.value !== undefined
      && company.priorPoint?.value !== null
      && company.priorPoint?.value !== undefined
        ? company.latestPoint.value - company.priorPoint.value
        : null,
    latestDateKey: company.latestPoint?.dateKey ?? null,
    latestPeriodLabel: company.latestPoint?.periodLabel ?? null,
    latestFilingType: company.latestPoint?.filingType ?? null
  }));

  const hasAnyData = companies.some((company) => company.latestPoint !== null);
  const hasPartialData = companies.some((company) => company.status !== 'ready')
    || companies.some((company) => company.points.some((point) => point.value === null));

  return {
    companies,
    chartData,
    latestRows,
    hasAnyData,
    hasPartialData
  };
}