import { createTheme, alpha, Shadows } from '@mui/material/styles';
import type { PaletteMode } from '@mui/material';

declare module '@mui/material/Paper' {
  interface PaperPropsVariantOverrides {
    highlighted: true;
  }
}
declare module '@mui/material/styles' {
  interface ColorRange {
    50: string;
    100: string;
    200: string;
    300: string;
    400: string;
    500: string;
    600: string;
    700: string;
    800: string;
    900: string;
  }

  interface PaletteColor extends ColorRange {}

  interface Palette {
    baseShadow: string;
    flows: {
      outflows: { primary: string; surface: string; text: string };
      inflows: { primary: string; surface: string; text: string };
    };
  }
}

const defaultTheme = createTheme();

const customShadows: Shadows = [...defaultTheme.shadows];

/**
 * Stripe-like indigo brand. #635BFF ≈ hsl(243, 76%, 59%).
 * Single brand hue — no multi-colour accents.
 */
export const brand = {
  50: 'hsl(250, 100%, 98%)',
  100: 'hsl(250, 95%, 95%)',
  200: 'hsl(249, 92%, 90%)',
  300: 'hsl(248, 92%, 80%)',
  400: 'hsl(245, 90%, 72%)',
  500: 'hsl(243, 76%, 59%)',
  600: 'hsl(243, 75%, 51%)',
  700: 'hsl(243, 78%, 42%)',
  800: 'hsl(242, 76%, 30%)',
  900: 'hsl(241, 75%, 20%)',
};

/** Cool, neutral grays. */
export const gray = {
  50: 'hsl(220, 35%, 97%)',
  100: 'hsl(220, 30%, 94%)',
  200: 'hsl(220, 20%, 89%)',
  300: 'hsl(220, 17%, 80%)',
  400: 'hsl(220, 15%, 64%)',
  500: 'hsl(220, 14%, 45%)',
  600: 'hsl(220, 13%, 36%)',
  700: 'hsl(220, 13%, 27%)',
  750: 'hsl(220, 13%, 20%)',
  800: 'hsl(220, 12%, 12%)',
  850: 'hsl(220, 10%, 8%)',
  900: 'hsl(220, 9%, 6%)',
};

export const green = {
  50: 'hsl(120, 80%, 98%)',
  100: 'hsl(120, 75%, 94%)',
  200: 'hsl(120, 75%, 87%)',
  300: 'hsl(120, 61%, 77%)',
  400: 'hsl(120, 44%, 53%)',
  500: 'hsl(120, 59%, 30%)',
  600: 'hsl(120, 70%, 25%)',
  700: 'hsl(120, 75%, 16%)',
  800: 'hsl(120, 84%, 10%)',
  900: 'hsl(120, 87%, 6%)',
};

export const orange = {
  50: 'hsl(45, 100%, 97%)',
  100: 'hsl(45, 92%, 90%)',
  200: 'hsl(45, 94%, 80%)',
  300: 'hsl(45, 90%, 65%)',
  400: 'hsl(45, 90%, 40%)',
  500: 'hsl(45, 90%, 35%)',
  600: 'hsl(45, 91%, 25%)',
  700: 'hsl(45, 94%, 20%)',
  800: 'hsl(45, 95%, 16%)',
  900: 'hsl(45, 93%, 12%)',
};

export const red = {
  50: 'hsl(0, 100%, 97%)',
  100: 'hsl(0, 92%, 90%)',
  200: 'hsl(0, 94%, 80%)',
  300: 'hsl(0, 90%, 65%)',
  400: 'hsl(0, 90%, 40%)',
  500: 'hsl(0, 90%, 30%)',
  600: 'hsl(0, 91%, 25%)',
  700: 'hsl(0, 94%, 18%)',
  800: 'hsl(0, 95%, 12%)',
  900: 'hsl(0, 93%, 6%)',
};

const darkBg = 'hsl(0, 0%, 9%)';
const darkPaper = 'hsl(0, 0%, 14%)';
const darkElevated = 'hsl(0, 0%, 19%)';

export const getDesignTokens = (mode: PaletteMode) => {
  customShadows[1] =
    mode === 'dark'
      ? '0 4px 16px rgba(0, 0, 0, 0.4), 0 8px 24px rgba(0, 0, 0, 0.3)'
      : 'hsla(220, 30%, 5%, 0.07) 0px 4px 16px 0px, hsla(220, 25%, 10%, 0.07) 0px 8px 16px -5px';

  return {
    palette: {
      mode,
      primary: {
        light: brand[400],
        main: brand[500],
        dark: brand[700],
        contrastText: brand[50],
        ...(mode === 'dark' && {
          contrastText: brand[50],
          light: 'hsl(245, 85%, 70%)',
          main: 'hsl(243, 76%, 64%)',
          dark: 'hsl(243, 78%, 48%)',
        }),
      },
      secondary: {
        light: gray[300],
        main: gray[600],
        dark: gray[800],
        contrastText: gray[50],
        ...(mode === 'dark' && {
          light: gray[200],
          main: gray[400],
          dark: gray[600],
          contrastText: gray[900],
        }),
      },
      info: {
        light: brand[100],
        main: brand[400],
        dark: brand[600],
        contrastText: gray[50],
        ...(mode === 'dark' && {
          contrastText: 'hsl(210, 30%, 80%)',
          light: 'hsl(245, 60%, 60%)',
          main: 'hsl(243, 55%, 52%)',
          dark: 'hsl(243, 50%, 38%)',
        }),
      },
      warning: {
        light: orange[300],
        main: orange[400],
        dark: orange[800],
        ...(mode === 'dark' && {
          light: 'hsl(45, 60%, 55%)',
          main: 'hsl(45, 55%, 45%)',
          dark: 'hsl(45, 50%, 30%)',
        }),
      },
      error: {
        light: red[300],
        main: red[400],
        dark: red[800],
        ...(mode === 'dark' && {
          light: 'hsl(0, 55%, 60%)',
          main: 'hsl(0, 55%, 50%)',
          dark: 'hsl(0, 50%, 35%)',
        }),
      },
      success: {
        light: green[300],
        main: green[400],
        dark: green[800],
        ...(mode === 'dark' && {
          light: 'hsl(120, 40%, 55%)',
          main: 'hsl(120, 40%, 45%)',
          dark: 'hsl(120, 35%, 30%)',
        }),
      },
      grey: {
        ...gray,
      },
      divider: mode === 'dark' ? 'hsla(0, 0%, 100%, 0.08)' : alpha(gray[300], 0.4),
      background: {
        default: 'hsl(0, 0%, 100%)',
        paper: 'hsl(220, 35%, 97%)',
        ...(mode === 'dark' && { default: darkBg, paper: darkPaper }),
      },
      text: {
        primary: gray[800],
        secondary: gray[600],
        warning: orange[400],
        ...(mode === 'dark' && { primary: 'hsl(0, 0%, 92%)', secondary: 'hsl(0, 0%, 60%)' }),
      },
      action: {
        hover: alpha(gray[200], 0.2),
        selected: `${alpha(gray[200], 0.3)}`,
        ...(mode === 'dark' && {
          hover: 'hsla(0, 0%, 100%, 0.06)',
          selected: 'hsla(0, 0%, 100%, 0.1)',
        }),
      },
      flows: {
        outflows: {
          primary: mode === 'dark' ? 'hsl(0, 55%, 60%)' : '#d32f2f',
          surface: mode === 'dark' ? 'hsla(0, 35%, 25%, 0.6)' : '#fdecea',
          text: mode === 'dark' ? 'hsl(0, 60%, 80%)' : '#b71c1c',
        },
        inflows: {
          primary: mode === 'dark' ? 'hsl(120, 40%, 55%)' : '#2e7d32',
          surface: mode === 'dark' ? 'hsla(120, 25%, 22%, 0.6)' : '#e8f5e9',
          text: mode === 'dark' ? 'hsl(120, 40%, 78%)' : '#1b5e20',
        },
      },
    },
    typography: {
      fontFamily: 'Inter, sans-serif',
      h1: {
        fontSize: defaultTheme.typography.pxToRem(40),
        fontWeight: 600,
        lineHeight: 1.1,
        letterSpacing: '-0.025em',
      },
      h2: {
        fontSize: defaultTheme.typography.pxToRem(32),
        fontWeight: 600,
        lineHeight: 1.2,
        letterSpacing: '-0.02em',
      },
      h3: {
        fontSize: defaultTheme.typography.pxToRem(26),
        fontWeight: 600,
        lineHeight: 1.25,
        letterSpacing: '-0.015em',
      },
      h4: {
        fontSize: defaultTheme.typography.pxToRem(20),
        fontWeight: 600,
        lineHeight: 1.4,
        letterSpacing: '-0.01em',
      },
      h5: {
        fontSize: defaultTheme.typography.pxToRem(18),
        fontWeight: 600,
        lineHeight: 1.4,
        letterSpacing: '-0.005em',
      },
      h6: {
        fontSize: defaultTheme.typography.pxToRem(16),
        fontWeight: 600,
        lineHeight: 1.5,
      },
      subtitle1: {
        fontSize: defaultTheme.typography.pxToRem(16),
        fontWeight: 500,
      },
      subtitle2: {
        fontSize: defaultTheme.typography.pxToRem(13),
        fontWeight: 500,
      },
      body1: {
        fontSize: defaultTheme.typography.pxToRem(15),
        lineHeight: 1.5,
      },
      body2: {
        fontSize: defaultTheme.typography.pxToRem(14),
        fontWeight: 400,
        lineHeight: 1.45,
      },
      caption: {
        fontSize: defaultTheme.typography.pxToRem(12),
        fontWeight: 400,
        lineHeight: 1.4,
      },
      overline: {
        fontSize: defaultTheme.typography.pxToRem(11),
        fontWeight: 600,
        lineHeight: 1.5,
        textTransform: 'uppercase',
        letterSpacing: '0.06em',
      },
    },
    shape: {
      borderRadius: 6,
    },
    shadows: customShadows,
  };
};