import type { ReactNode } from 'react'
import type { ColorValue, StyleProp, ViewProps, ViewStyle } from 'react-native'

export type CurvePreset = 'smooth' | 'smoother' | 'sharp' | 'gentle' | 'soft' | 'linear'

export interface CubicBezierCurve {
  type: 'cubicBezier'
  x1: number
  y1: number
  x2: number
  y2: number
}

export interface StopsCurve {
  type: 'stops'
  /** alpha values in [0,1], inner edge to outer edge. minimum 2 entries. */
  values: [number, number, ...number[]]
}

export type EdgeFadeCurve = CurvePreset | CubicBezierCurve | StopsCurve

export type EdgeFadeMode = 'mask' | 'overlay' | 'blur'

export interface EdgeConfig {
  /** fade depth in dp. overrides the component-level `size`. */
  size?: number
  /** gradient curve. overrides the component-level `curve`. */
  curve?: EdgeFadeCurve
  /** per-edge overlay color (overlay mode only). overrides `color`. */
  color?: ColorValue
}

export interface EdgeFadeProps extends ViewProps {
  top?: boolean | number | EdgeConfig
  bottom?: boolean | number | EdgeConfig
  left?: boolean | number | EdgeConfig
  right?: boolean | number | EdgeConfig
  /** logical leading edge. maps to `left` in LTR, `right` in RTL. overrides the physical prop. */
  start?: boolean | number | EdgeConfig
  /** logical trailing edge. maps to `right` in LTR, `left` in RTL. overrides the physical prop. */
  end?: boolean | number | EdgeConfig
  /** default fade depth in dp for all enabled edges. */
  size?: number
  /** default gradient curve for all enabled edges. */
  curve?: EdgeFadeCurve
  /**
   * 'mask' paints no color: children alpha-fade to transparent (native
   * primitive, the only way to alpha-mask on native). 'overlay' paints a
   * color gradient over the children (RN core backgroundImage gradients,
   * no native code). 'blur' progressively blurs the children toward the
   * enabled edges (native primitive). inferred from `color` when omitted:
   * color means overlay, otherwise mask; blur is always explicit.
   */
  mode?: EdgeFadeMode
  /**
   * overlay mode: gradient target color, opaque at the outer edge fading to
   * transparent at the inner edge. per-edge `EdgeConfig.color` overrides it.
   * blur mode: optional frost-veil tint over the blur (omit for pure blur).
   * ignored in mask mode.
   */
  color?: ColorValue
  /**
   * blur mode only: maximum blur radius in dp at the outer edge, ramping
   * from sharp at the inner edge along each edge's curve.
   */
  blurRadius?: number
  /**
   * blur mode only: fraction of the band (inner to outer, clamped 0.05-1)
   * over which the curve's blur envelope completes. smaller values reach
   * full blur sooner and hold it for the rest of the band.
   */
  frostProgression?: number
  /**
   * corner radius in dp, applied with the fade (mask mode) or as a clipped
   * container (overlay mode). use this instead of `style.borderRadius`,
   * which is ignored with a dev warning.
   */
  radius?: number
  style?: StyleProp<ViewStyle>
}

export type BlurTint =
  | 'light'
  | 'dark'
  | 'default'
  | 'extraLight'
  | 'regular'
  | 'prominent'
  | 'systemUltraThinMaterial'
  | 'systemThinMaterial'
  | 'systemMaterial'
  | 'systemThickMaterial'
  | 'systemChromeMaterial'
  | 'systemUltraThinMaterialLight'
  | 'systemThinMaterialLight'
  | 'systemMaterialLight'
  | 'systemThickMaterialLight'
  | 'systemChromeMaterialLight'
  | 'systemUltraThinMaterialDark'
  | 'systemThinMaterialDark'
  | 'systemMaterialDark'
  | 'systemThickMaterialDark'
  | 'systemChromeMaterialDark'

export interface BlurProps extends ViewProps {
  /** blur strength, expo units 0-100. default 50. */
  intensity?: number
  /** material tint. default 'default'. */
  tint?: BlurTint
  style?: StyleProp<ViewStyle>
}

export interface MaskProps extends ViewProps {
  /**
   * the mask subtree: opaque pixels show the content, transparent pixels
   * hide it. rendered offscreen (never displayed) and must fill the whole
   * view to mask it. anything but an element warns once and renders the
   * children unmasked.
   */
  maskElement?: ReactNode
  style?: StyleProp<ViewStyle>
}