import { View } from "@react-pdf/renderer";
import type { ReactNode } from "react";
import { colsDetailed, type ColSpec } from "../engine/columns";
import { PlanError } from "../engine/errors";
import { TABLE_HEAD_ID, TABLE_ROW_PREFIX } from "../engine/ids";
import { drawnText, type Measurer } from "../engine/measure";
import { resolveFace, roleToken, type RoleName, type TypeToken } from "../fonts/roles";
import { AvailableWidthProvider } from "./AvailableWidth";
import { pdfFlags } from "./pdfProps";
import { Cell, Row } from "./Row";
import { Txt } from "./Txt";

export interface TableRoles {
  head: RoleName | TypeToken;
  body: RoleName | TypeToken;
}

export interface TableLook {
  /** Horizontal cell padding, pt per side. Default 0. */
  padX?: number;
  /** Vertical cell padding, pt per side. Default 4. */
  padY?: number;
  /** Bottom border of each row in pt (counted in the row height). Default 0. */
  border?: number;
  faceOverrides?: Readonly<Record<string, string>>;
}

export interface ItemsTablePlanInput extends TableLook {
  columns: ColSpec[];
  gap: number;
  /** Table width in pt (the content width of the page, or of the cell holding the table). */
  width: number;
  header: string[];
  rows: string[][];
  measurer: Measurer;
  roles: TableRoles;
  /** Height of whatever follows the last row and must stay with it (the totals). */
  tailH?: number;
  /** Wrap-area height of one page. With `tailH` it lets the planner prove the tail can ever fit. */
  contentH?: number;
}

export interface ItemsTablePlan {
  widths: number[];
  headH: number;
  rowHeights: number[];
  firstRowH: number;
  /** Predicted line count per row (the tallest cell). */
  rowLines: number[];
}

function cellHeight(m: Measurer, role: RoleName | TypeToken, text: string, inner: number, look: TableLook): { lines: number; height: number } {
  const t = roleToken(role);
  if (t.leading === undefined) throw new PlanError("table roles need a leading", "invalid-plan");
  if (/[\n\t]/.test(text)) throw new PlanError("table cells must not contain \\n or \\t", "invalid-plan");
  const lines = Math.max(
    1,
    m.wrapLines(drawnText(t, text), inner, {
      face: resolveFace(t.face, look.faceOverrides),
      weight: t.weight,
      italic: t.italic ?? false,
      size: t.size,
      letterSpacing: (t.tracking ?? 0) * t.size,
    }).length,
  );
  return { lines, height: lines * t.leading };
}

/**
 * Plans an items table without rendering: column widths, the wrapped height of the header and of
 * every row. Heights are estimates from the measurer (see Measurer.wrapLines) and feed
 * TableGuard/BottomSpacer presence values.
 *
 * Throws PlanError("tail-too-tall") when the totals tail could never share a page with the header and
 * the last row: `tailH <= contentH - headH - lastRowH`.
 */
export function planItemsTable(input: ItemsTablePlanInput): ItemsTablePlan {
  const { columns, gap, width, header, rows, measurer, roles, tailH, contentH } = input;
  const padX = input.padX ?? 0;
  const padY = input.padY ?? 4;
  const border = input.border ?? 0;
  if (header.length !== columns.length) throw new PlanError(`${header.length} header cells for ${columns.length} columns`, "invalid-plan");
  if (rows.length === 0) throw new PlanError("an items table needs at least one row", "invalid-plan");
  for (const r of rows) if (r.length !== columns.length) throw new PlanError(`row has ${r.length} cells for ${columns.length} columns`, "invalid-plan");

  const { widths } = colsDetailed(width, columns, gap);
  const inner = widths.map((w) => Math.max(0, w - 2 * padX));
  const heightOf = (role: RoleName | TypeToken, cells: string[]) => {
    const hs = cells.map((c, i) => cellHeight(measurer, role, c, inner[i], input));
    return { lines: Math.max(...hs.map((h) => h.lines)), height: Math.max(...hs.map((h) => h.height)) + 2 * padY + border };
  };

  const headH = heightOf(roles.head, header).height;
  const measured = rows.map((r) => heightOf(roles.body, r));
  const rowHeights = measured.map((r) => r.height);

  if (tailH !== undefined && contentH !== undefined) {
    const lastRowH = rowHeights[rowHeights.length - 1];
    if (tailH > contentH - headH - lastRowH + 1e-6) {
      throw new PlanError(
        `totals tail ${tailH} pt cannot share a ${contentH} pt page with the header (${headH}) and the last row (${lastRowH})`,
        "tail-too-tall",
      );
    }
  }
  return { widths, headH, rowHeights, firstRowH: rowHeights[0], rowLines: measured.map((r) => r.lines) };
}

export interface TableRowsProps extends TableLook {
  columns: ColSpec[];
  gap: number;
  width: number;
  header: string[];
  rows: string[][];
  roles: TableRoles;
  /** Per column; default left. */
  align?: Array<"left" | "right" | "center">;
  /** Passed as minPresenceAhead on the last row so the totals never start a page without an item row. */
  tailH?: number;
  /** Content after the last row, inside the table container (the totals). */
  tail?: ReactNode;
  headerStyle?: Record<string, unknown>;
  rowStyle?: Record<string, unknown>;
  borderColor?: string;
}

/**
 * Header (a `fixed` first child, so it repeats on every page the table spans) followed by one
 * `wrap={false}` row per item. The container has no padding or border; those go on the rows, because
 * the repeated header is positioned against the container's top.
 */
export function TableRows({ columns, gap, width, header, rows, roles, align = [], tailH, tail, headerStyle, rowStyle, borderColor, ...look }: TableRowsProps) {
  const padX = look.padX ?? 0;
  const padY = look.padY ?? 4;
  const border = look.border ?? 0;
  const { widths } = colsDetailed(width, columns, gap);
  const cellStyle = (extra?: Record<string, unknown>) => ({
    ...(border ? { borderBottomWidth: border, borderBottomColor: borderColor ?? "#000000", borderBottomStyle: "solid" } : {}),
    ...extra,
  });
  const cells = (role: RoleName | TypeToken, values: string[]) =>
    values.map((v, i) => (
      <Cell key={i} padding={{ top: padY, bottom: padY, left: padX, right: padX }}>
        <Txt role={role} width={Math.max(0, widths[i] - 2 * padX)} align={align[i]} faceOverrides={look.faceOverrides}>
          {v}
        </Txt>
      </Cell>
    ));

  return (
    <AvailableWidthProvider width={width}>
      <View>
        <Row id={TABLE_HEAD_ID} widths={columns} gap={gap} width={width} fixed style={cellStyle(headerStyle)}>
          {cells(roles.head, header)}
        </Row>
        {rows.map((r, i) => (
          <Row
            key={i}
            id={`${TABLE_ROW_PREFIX}${i}`}
            widths={columns}
            gap={gap}
            width={width}
            {...pdfFlags({ wrap: false, minPresenceAhead: i === rows.length - 1 ? tailH : undefined })}
            style={cellStyle(rowStyle)}
          >
            {cells(roles.body, r)}
          </Row>
        ))}
        {tail}
      </View>
    </AvailableWidthProvider>
  );
}