import flattenColorPalette from "tailwindcss/lib/util/flattenColorPalette";
import { parseBoxShadowValue } from "tailwindcss/lib/util/parseBoxShadowValue";
import toColorValue from "tailwindcss/lib/util/toColorValue";
import transformThemeValue from "tailwindcss/lib/util/transformThemeValue";
import plugin from "tailwindcss/plugin";

export const shadows = plugin(({ matchUtilities, theme, ...rest }) => {
  const { addDefaults } = rest as any;
  const boxShadowEntries = Object.entries(theme("boxShadow") ?? {});

  function getElevation(value: any) {
    let elevationKey: any = boxShadowEntries.find(
      (entry) => entry[1] === value,
    )?.[0];

    let elevation = theme("elevation")?.[elevationKey];

    if (elevation === undefined) {
      elevation = Number.parseFloat(value.split(" ")[2]);
    }

    if (elevation === undefined || Number.isNaN(elevation)) {
      elevation = 0;
    }

    return elevation;
  }

  addDefaults("box-shadow", {
    "--tw-ring-offset-shadow": "0 0 #0000",
    "--tw-ring-shadow": "0 0 #0000",
    "--tw-shadow": "0 0 #0000",
    "--tw-shadow-colored": "0 0 #0000",
  });

  if (process.env.NATIVEWIND_OS === "android") {
    matchUtilities(
      {
        elevation: (value) => {
          return {
            "-rn-elevation": value,
          } as any;
        },
      },
      { values: theme("elevation") },
    );
  }

  matchUtilities(
    {
      shadow: (value) => {
        const elevation = getElevation(value);

        let transformValue = transformThemeValue("boxShadow");
        value = transformValue(value);
        let ast = parseBoxShadowValue(value);

        const firstValid = ast.find((shadow: any) => shadow.valid);

        if (!firstValid) {
          return;
        }

        const { x, y, blur, color } = firstValid;

        const shadow = {
          "--tw-shadow-color": value === "none" ? "#0000" : color,
          "-rn-shadow-color": "var(--tw-shadow-color)",
          "@rn-move -rn-shadow-offset-width \\&shadow-offset\\.width": "true",
          "-rn-shadow-offset-width": x,
          "@rn-move -rn-shadow-offset-height \\&shadow-offset\\.height": "true",
          "-rn-shadow-offset-height": y,
          "-rn-shadow-radius": blur ?? 0,
          "-rn-shadow-opacity": 1,
        } as any;

        if (process.env.NATIVEWIND_OS === "android") {
          shadow["-rn-elevation"] = elevation;
        }

        return shadow;
      },
    },
    { values: theme("boxShadow"), type: ["shadow"] },
  );

  matchUtilities(
    {
      shadow: (value) => {
        return {
          "--tw-shadow-color": toColorValue(value),
        };
      },
    },
    {
      values: flattenColorPalette(theme("boxShadowColor")),
      type: ["color", "any"],
    },
  );
});