import type { SkFont } from "@shopify/react-native-skia";
import { measureFontTextWidth } from "../lib/measureFontTextWidth";
import {
  dotGlowRadialOutset,
  minPaddingRightForBadgeYAxisAlign,
  minPaddingRightForYAxisWithPulse,
  pulseRadialOutset,
  resolveAutoLeft,
  resolveAutoRight,
  resolvePadding,
  type ChartPadding,
} from "../draw/line";
import type { BadgeMetrics, ChartInsets, LiveChartPalette } from "../types";

export interface ChartLayoutConfig {
  palette: LiveChartPalette;
  lineWidthOverride?: number;
  insetsOverride?: ChartInsets;
  yAxis: boolean;
  /** Float the y-axis over a full-width plot (no reserved right gutter). */
  yAxisFloat?: boolean;
  badge: boolean;
  /** Badge pill geometry tokens. Omit for built-in defaults. */
  badgeMetrics?: BadgeMetrics;
  /**
   * When true (default if omitted and `badge` is true), reserve the wide right gutter for the badge.
   * Set false when the badge is anchored left of the live dot (`position: "left"`).
   */
  badgeUsesRightGutter?: boolean;
  /** When false, bottom inset shrinks (no x-axis labels). Default true. */
  xAxis?: boolean;
  /**
   * Reserved volume-bar band height (px) below the candles. Added to the bottom
   * padding so the candle/price plot shrinks by this much; the x-axis offsets
   * back down by it so its labels stay pinned to the bottom (see XAxisOverlay).
   * `0`/omitted = no band. An explicit `insetsOverride.bottom` suppresses it.
   */
  volumeBandHeight?: number;
  /** Skia font for measuring label width. When provided with formatValue + currentValue, padding auto-sizes. */
  font?: SkFont;
  /** Worklet formatter — called on JS thread here to measure label width */
  formatValue?: (v: number) => string;
  /** Current value read from SharedValue on JS thread — used to produce a sample label for measurement */
  currentValue?: number;
  /**
   * Live dot pulse (LiveChart); floors top/right/bottom auto-padding so the ring
   * is not clipped. An explicit `insetsOverride` on a side wins over this floor.
   */
  pulse?: { maxRadius: number; strokeWidth: number } | null;
  /**
   * Static live-dot glow; floors auto-padding so its blurred falloff is not
   * clipped. Explicit side insets still win.
   */
  dotGlow?: { radius: number; blur: number } | null;
  /**
   * When false and the badge uses the right gutter, omit the tail and
   * round-cap inset from the right padding.
   */
  badgeShowTail?: boolean;
  /** Multi-series dot radius — used to add spacing between dots and Y-axis labels. */
  multiSeriesDotRadius?: number;
  /** When true, inline series labels sit right of dots and need extra right padding. */
  multiSeriesValueLabel?: boolean;
  /** Measured width of the widest series label (e.g. "Maybe"). Used when `multiSeriesValueLabel` is true. */
  multiSeriesMaxLabelWidth?: number;
}

export interface ChartLayoutResult {
  strokeWidth: number;
  padding: ChartPadding;
}

/** Right inset (px) for a floating y-axis — just keeps the plot off the edge. */
const FLOAT_AXIS_RIGHT_INSET = 6;

export function resolveChartLayout(
  config: ChartLayoutConfig,
): ChartLayoutResult {
  const badgeUsesRightGutter =
    config.badge && (config.badgeUsesRightGutter ?? true);
  const showTail = config.badgeShowTail ?? true;
  const xAxis = config.xAxis ?? true;

  let measuredYAxisLabelWidth: number | undefined;

  // ── Right inset ──────────────────────────────────────────────────────────
  let rightPad: number;
  if (config.insetsOverride?.right != null) {
    rightPad = config.insetsOverride.right;
  } else if (
    config.font &&
    config.formatValue &&
    config.currentValue != null &&
    (badgeUsesRightGutter || !config.badge || config.yAxis)
  ) {
    const v = config.currentValue;
    const samples = [v, v / 10, v / 100, v * 10].map(config.formatValue);
    measuredYAxisLabelWidth = Math.max(
      ...samples.map((s) => measureFontTextWidth(config.font!, s)),
    );
    const dotR = config.multiSeriesDotRadius ?? 0;
    const seriesLabelW = config.multiSeriesMaxLabelWidth ?? 0;
    rightPad = badgeUsesRightGutter
      ? minPaddingRightForBadgeYAxisAlign(
          config.font.getSize(),
          measuredYAxisLabelWidth,
          showTail,
          config.badgeMetrics,
        )
      : config.multiSeriesValueLabel && config.yAxis
        ? Math.max(
            dotR + 8 + seriesLabelW + 8 + measuredYAxisLabelWidth + 8,
            44,
          )
        : config.multiSeriesValueLabel
          ? Math.max(dotR + 8 + seriesLabelW + 8, 44)
          : config.yAxis
            ? Math.max(measuredYAxisLabelWidth + 16 + dotR * 2, 44)
            : resolveAutoRight(false, false);
  } else {
    rightPad = resolveAutoRight(
      config.yAxis,
      badgeUsesRightGutter,
      showTail,
      config.badgeMetrics,
    );
  }

  const pulseOutset = config.pulse
    ? pulseRadialOutset(config.pulse.maxRadius, config.pulse.strokeWidth)
    : 0;
  const glowOutset = config.dotGlow
    ? dotGlowRadialOutset(config.dotGlow.radius, config.dotGlow.blur)
    : 0;
  const dotEffectOutset = Math.max(pulseOutset, glowOutset);

  // A right-gutter badge uses its pill layout instead of the bare centered label
  // column, so the bare-axis effect/label floor must not override badge sizing.
  // The badge renders above the dot effects; the general outlet floor below
  // still prevents canvas-edge clipping.
  if (
    dotEffectOutset > 0 &&
    config.yAxis &&
    !badgeUsesRightGutter &&
    config.insetsOverride?.right == null
  ) {
    const labelW = measuredYAxisLabelWidth ?? 49;
    rightPad = Math.max(
      rightPad,
      minPaddingRightForYAxisWithPulse(dotEffectOutset, labelW),
    );
  }

  // ── Left inset ───────────────────────────────────────────────────────────
  let leftPad: number;
  if (config.insetsOverride?.left != null) {
    leftPad = config.insetsOverride.left;
  } else {
    leftPad = resolveAutoLeft(false);
  }

  const base = resolvePadding(
    config.insetsOverride,
    config.yAxis,
    badgeUsesRightGutter,
    false,
    xAxis,
    showTail,
    config.badgeMetrics,
  );

  let padding: ChartPadding = { ...base, right: rightPad, left: leftPad };
  if (dotEffectOutset > 0) {
    // The pulse/glow needs this much room or it clips at the canvas edge, so it
    // acts as a floor on the *auto* padding. An explicitly-provided inset always
    // wins, though — the caller opts into any clipping that causes (issue #128).
    // Every other auto-padding already respects an explicit inset (see the
    // right/left branches and resolvePadding); this is the last place that didn't.
    const ins = config.insetsOverride;
    padding = {
      ...padding,
      right:
        ins?.right != null
          ? padding.right
          : Math.max(padding.right, dotEffectOutset),
      top:
        ins?.top != null ? padding.top : Math.max(padding.top, dotEffectOutset),
      bottom:
        ins?.bottom != null
          ? padding.bottom
          : Math.max(padding.bottom, dotEffectOutset),
    };
  }

  // Floating axis: collapse the right gutter LAST so it wins over the label,
  // pulse, and badge reservations above — the plot runs full-width with the price
  // axis (and the live-value badge) floating on top. An explicit right inset still
  // wins. (The live-dot pulse may clip at the right edge in this mode.)
  if (config.yAxisFloat && config.insetsOverride?.right == null) {
    padding = { ...padding, right: FLOAT_AXIS_RIGHT_INSET };
  }

  // Volume band: reserve extra space at the bottom by ADDING the band height to
  // the (already finalized) bottom padding, so every price Y-projection shrinks
  // for free. The x-axis is shifted back down by the same amount (XAxisOverlay)
  // so its labels stay at the very bottom, below the band. An explicit bottom
  // inset opts out (the caller owns the full bottom space).
  if (
    config.volumeBandHeight &&
    config.volumeBandHeight > 0 &&
    config.insetsOverride?.bottom == null
  ) {
    padding = { ...padding, bottom: padding.bottom + config.volumeBandHeight };
  }

  return {
    strokeWidth: config.lineWidthOverride ?? config.palette.lineWidth,
    padding,
  };
}