import { normalizeEstimateDemandLine, summarizeEstimateDemandLines } from "@capakraken/engine";
import { CreateEstimateSchema } from "@capakraken/shared";
import { z } from "zod";
import { lookupRatesBatch } from "../lib/rate-card-lookup.js";

function buildComputedMetrics(demandLines: z.infer<typeof CreateEstimateSchema>["demandLines"]) {
  const summary = summarizeEstimateDemandLines(demandLines);

  return [
    {
      key: "total_hours",
      label: "Total Hours",
      metricGroup: "summary",
      valueDecimal: summary.totalHours,
      metadata: {},
    },
    {
      key: "total_cost",
      label: "Total Cost",
      metricGroup: "summary",
      valueDecimal: summary.totalCostCents / 100,
      valueCents: summary.totalCostCents,
      currency: demandLines[0]?.currency ?? "EUR",
      metadata: {},
    },
    {
      key: "total_price",
      label: "Total Price",
      metricGroup: "summary",
      valueDecimal: summary.totalPriceCents / 100,
      valueCents: summary.totalPriceCents,
      currency: demandLines[0]?.currency ?? "EUR",
      metadata: {},
    },
    {
      key: "margin",
      label: "Margin",
      metricGroup: "summary",
      valueDecimal: summary.marginCents / 100,
      valueCents: summary.marginCents,
      currency: demandLines[0]?.currency ?? "EUR",
      metadata: {},
    },
    {
      key: "margin_percent",
      label: "Margin %",
      metricGroup: "summary",
      valueDecimal: summary.marginPercent,
      metadata: {},
    },
  ];
}

function normalizeDemandLines<
  T extends {
    demandLines: z.infer<typeof CreateEstimateSchema>["demandLines"];
    resourceSnapshots: z.infer<typeof CreateEstimateSchema>["resourceSnapshots"];
  },
>(input: T, baseCurrency: string) {
  const snapshotsByResourceId = new Map(
    input.resourceSnapshots
      .filter(
        (
          snapshot,
        ): snapshot is (typeof input.resourceSnapshots)[number] & {
          resourceId: string;
        } => typeof snapshot.resourceId === "string" && snapshot.resourceId.length > 0,
      )
      .map((snapshot) => [snapshot.resourceId, snapshot]),
  );

  return input.demandLines.map((line) =>
    normalizeEstimateDemandLine(line, {
      resourceSnapshot: line.resourceId != null ? snapshotsByResourceId.get(line.resourceId) : null,
      defaultCurrency: baseCurrency,
    }),
  );
}

export function withComputedMetrics<
  T extends {
    demandLines: z.infer<typeof CreateEstimateSchema>["demandLines"];
    resourceSnapshots: z.infer<typeof CreateEstimateSchema>["resourceSnapshots"];
    metrics: z.infer<typeof CreateEstimateSchema>["metrics"];
  },
>(input: T, baseCurrency: string) {
  const normalizedDemandLines = normalizeDemandLines(input, baseCurrency);
  const computedMetrics = buildComputedMetrics(normalizedDemandLines);
  const computedKeys = new Set(computedMetrics.map((metric) => metric.key));

  return {
    ...input,
    demandLines: normalizedDemandLines,
    metrics: [
      ...input.metrics.filter((metric) => !computedKeys.has(metric.key)),
      ...computedMetrics,
    ],
  };
}

export async function autoFillDemandLineRates(
  // eslint-disable-next-line @typescript-eslint/no-explicit-any
  db: any,
  demandLines: z.infer<typeof CreateEstimateSchema>["demandLines"],
  projectId?: string | null,
): Promise<{
  demandLines: z.infer<typeof CreateEstimateSchema>["demandLines"];
  autoFilledIndices: number[];
}> {
  let clientId: string | null = null;
  if (projectId) {
    const project = await db.project.findUnique({
      where: { id: projectId },
      select: { clientId: true },
    });
    clientId = project?.clientId ?? null;
  }

  // Identify which lines need auto-fill and collect their lookup params
  const needsLookup: {
    index: number;
    params: { chapter: string | null; roleId: string | null };
  }[] = [];
  for (let i = 0; i < demandLines.length; i++) {
    const line = demandLines[i]!;
    const isDefaultRate = line.costRateCents === 0 && line.billRateCents === 0;
    const hasExplicitSource = line.rateSource != null && line.rateSource.length > 0;
    if (isDefaultRate && !hasExplicitSource) {
      needsLookup.push({
        index: i,
        params: { chapter: line.chapter ?? null, roleId: line.roleId ?? null },
      });
    }
  }

  if (needsLookup.length === 0) {
    return { demandLines, autoFilledIndices: [] };
  }

  // Single DB query for all rate card lines, scored locally per demand line
  const results = await lookupRatesBatch(
    db,
    clientId,
    needsLookup.map((entry) => entry.params),
  );

  const autoFilledIndices: number[] = [];
  const enriched = [...demandLines];
  for (let i = 0; i < needsLookup.length; i++) {
    const result = results[i];
    if (!result) continue;
    const { index } = needsLookup[i]!;
    autoFilledIndices.push(index);
    const line = demandLines[index]!;
    const existingMetadata = (line.metadata ?? {}) as Record<string, unknown>;
    enriched[index] = {
      ...line,
      costRateCents: result.costRateCents,
      billRateCents: result.billRateCents,
      currency: result.currency,
      rateSource: `rate-card:${result.rateCardId}`,
      metadata: {
        ...existingMetadata,
        autoAppliedRateCard: {
          rateCardId: result.rateCardId,
          rateCardLineId: result.rateCardLineId,
          rateCardName: result.rateCardName,
          appliedAt: new Date().toISOString(),
        },
      },
    };
  }

  return { demandLines: enriched, autoFilledIndices };
}