import type { ColumnDef } from "../components/data-table/types"
import { resolveColumnFilter } from "./column-filter"
import {
  computeNumericColumnBounds,
  defaultRangeStep,
} from "./column-filter-range-policy"
import {
  derivePersonFilterOptions,
  isPersonSelectFilter,
  type PersonFilterOption,
} from "./column-filter-person-options"

export type FilterFieldRuntimeContext = {
  /** Person avatar pickers — derived from rows when `cellKind` is person / people-rail. */
  personOptions?: PersonFilterOption[]
  /** Data-derived numeric bounds for range sliders. */
  rangeMin?: number
  rangeMax?: number
  rangeStep?: number
}

export function buildFilterFieldContextMap<T extends Record<string, unknown>>(
  rows: T[],
  columns: ColumnDef<T>[],
): Record<string, FilterFieldRuntimeContext> {
  const out: Record<string, FilterFieldRuntimeContext> = {}

  for (const col of columns) {
    const resolved = resolveColumnFilter(col)
    if (!resolved) continue

    const ctx: FilterFieldRuntimeContext = {}

    if (isPersonSelectFilter(col.cellKind)) {
      ctx.personOptions = derivePersonFilterOptions(rows, col.key, col.cellKind)
    }

    if (resolved.type === "range") {
      const explicitMin = resolved.rangeMin
      const explicitMax = resolved.rangeMax
      const useDataBounds =
        explicitMin === undefined &&
        explicitMax === undefined &&
        (resolved.dataBounds === true ||
          col.cellKind === "currency" ||
          col.cellKind === "numeric")

      if (useDataBounds) {
        const { min, max } = computeNumericColumnBounds(rows, col.key)
        ctx.rangeMin = min
        ctx.rangeMax = max
        ctx.rangeStep = resolved.rangeStep ?? defaultRangeStep(min, max, resolved.rangeUnit)
      } else {
        ctx.rangeMin = explicitMin ?? 0
        ctx.rangeMax = explicitMax ?? 100
        ctx.rangeStep = resolved.rangeStep ?? defaultRangeStep(ctx.rangeMin, ctx.rangeMax, resolved.rangeUnit)
      }
    }

    if (Object.keys(ctx).length > 0) {
      out[col.key] = ctx
    }
  }

  return out
}