"use client";

import { motion } from "motion/react";
import { useTheme } from "next-themes";
import { useCallback, useEffect, useId, useState } from "react";

import { cn } from "@/lib/utils";

// ///////////////////////////////////////////////////////////////////////////
// Types
export type AnimationVariant = "circle" | "rectangle" | "gif" | "polygon" | "circle-blur";
export type AnimationStart =
	| "top-left"
	| "top-right"
	| "bottom-left"
	| "bottom-right"
	| "center"
	| "top-center"
	| "bottom-center"
	| "bottom-up"
	| "top-down"
	| "left-right"
	| "right-left";

interface Animation {
	name: string;
	css: string;
}

// ///////////////////////////////////////////////////////////////////////////
// Helper functions

const getPositionCoords = (position: AnimationStart) => {
	switch (position) {
		case "top-left":
			return { cx: "0", cy: "0" };
		case "top-right":
			return { cx: "40", cy: "0" };
		case "bottom-left":
			return { cx: "0", cy: "40" };
		case "bottom-right":
			return { cx: "40", cy: "40" };
		case "top-center":
			return { cx: "20", cy: "0" };
		case "bottom-center":
			return { cx: "20", cy: "40" };
		case "bottom-up":
		case "top-down":
		case "left-right":
		case "right-left":
			return { cx: "20", cy: "20" };
	}
};

const generateSVG = (variant: AnimationVariant, start: AnimationStart) => {
	if (variant === "circle-blur") {
		if (start === "center") {
			return `data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 40 40"><defs><filter id="blur"><feGaussianBlur stdDeviation="2"/></filter></defs><circle cx="20" cy="20" r="18" fill="white" filter="url(%23blur)"/></svg>`;
		}
		const positionCoords = getPositionCoords(start);
		if (!positionCoords) {
			throw new Error(`Invalid start position: ${start}`);
		}
		const { cx, cy } = positionCoords;
		return `data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 40 40"><defs><filter id="blur"><feGaussianBlur stdDeviation="2"/></filter></defs><circle cx="${cx}" cy="${cy}" r="18" fill="white" filter="url(%23blur)"/></svg>`;
	}

	if (start === "center") return;

	if (variant === "rectangle") return "";

	const positionCoords = getPositionCoords(start);
	if (!positionCoords) {
		throw new Error(`Invalid start position: ${start}`);
	}
	const { cx, cy } = positionCoords;

	if (variant === "circle") {
		return `data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 40 40"><circle cx="${cx}" cy="${cy}" r="20" fill="white"/></svg>`;
	}

	return "";
};

const getTransformOrigin = (start: AnimationStart) => {
	switch (start) {
		case "top-left":
			return "top left";
		case "top-right":
			return "top right";
		case "bottom-left":
			return "bottom left";
		case "bottom-right":
			return "bottom right";
		case "top-center":
			return "top center";
		case "bottom-center":
			return "bottom center";
		case "bottom-up":
		case "top-down":
		case "left-right":
		case "right-left":
			return "center";
	}
};

export const createAnimation = (
	variant: AnimationVariant,
	start: AnimationStart = "center",
	blur = false,
	url?: string
): Animation => {
	const svg = generateSVG(variant, start);
	const transformOrigin = getTransformOrigin(start);

	if (variant === "rectangle") {
		const getClipPath = (direction: AnimationStart) => {
			switch (direction) {
				case "bottom-up":
					return {
						from: "polygon(0% 100%, 100% 100%, 100% 100%, 0% 100%)",
						to: "polygon(0% 0%, 100% 0%, 100% 100%, 0% 100%)",
					};
				case "top-down":
					return {
						from: "polygon(0% 0%, 100% 0%, 100% 0%, 0% 0%)",
						to: "polygon(0% 0%, 100% 0%, 100% 100%, 0% 100%)",
					};
				case "left-right":
					return {
						from: "polygon(0% 0%, 0% 0%, 0% 100%, 0% 100%)",
						to: "polygon(0% 0%, 100% 0%, 100% 100%, 0% 100%)",
					};
				case "right-left":
					return {
						from: "polygon(100% 0%, 100% 0%, 100% 100%, 100% 100%)",
						to: "polygon(0% 0%, 100% 0%, 100% 100%, 0% 100%)",
					};
				case "top-left":
					return {
						from: "polygon(0% 0%, 0% 0%, 0% 0%, 0% 0%)",
						to: "polygon(0% 0%, 100% 0%, 100% 100%, 0% 100%)",
					};
				case "top-right":
					return {
						from: "polygon(100% 0%, 100% 0%, 100% 0%, 100% 0%)",
						to: "polygon(0% 0%, 100% 0%, 100% 100%, 0% 100%)",
					};
				case "bottom-left":
					return {
						from: "polygon(0% 100%, 0% 100%, 0% 100%, 0% 100%)",
						to: "polygon(0% 0%, 100% 0%, 100% 100%, 0% 100%)",
					};
				case "bottom-right":
					return {
						from: "polygon(100% 100%, 100% 100%, 100% 100%, 100% 100%)",
						to: "polygon(0% 0%, 100% 0%, 100% 100%, 0% 100%)",
					};
				default:
					return {
						from: "polygon(0% 100%, 100% 100%, 100% 100%, 0% 100%)",
						to: "polygon(0% 0%, 100% 0%, 100% 100%, 0% 100%)",
					};
			}
		};

		const clipPath = getClipPath(start);

		return {
			name: `${variant}-${start}${blur ? "-blur" : ""}`,
			css: `
       ::view-transition-group(root) {
        animation-duration: 0.7s;
        animation-timing-function: var(--expo-out);
      }
            
      ::view-transition-new(root) {
        animation-name: reveal-light-${start}${blur ? "-blur" : ""};
        ${blur ? "filter: blur(2px);" : ""}
      }

      ::view-transition-old(root),
      .dark::view-transition-old(root) {
        animation: none;
        z-index: -1;
      }
      .dark::view-transition-new(root) {
        animation-name: reveal-dark-${start}${blur ? "-blur" : ""};
        ${blur ? "filter: blur(2px);" : ""}
      }

      @keyframes reveal-dark-${start}${blur ? "-blur" : ""} {
        from {
          clip-path: ${clipPath.from};
          ${blur ? "filter: blur(8px);" : ""}
        }
        ${blur ? "50% { filter: blur(4px); }" : ""}
        to {
          clip-path: ${clipPath.to};
          ${blur ? "filter: blur(0px);" : ""}
        }
      }

      @keyframes reveal-light-${start}${blur ? "-blur" : ""} {
        from {
          clip-path: ${clipPath.from};
          ${blur ? "filter: blur(8px);" : ""}
        }
        ${blur ? "50% { filter: blur(4px); }" : ""}
        to {
          clip-path: ${clipPath.to};
          ${blur ? "filter: blur(0px);" : ""}
        }
      }
      `,
		};
	}
	if (variant === "circle" && start === "center") {
		return {
			name: `${variant}-${start}${blur ? "-blur" : ""}`,
			css: `
       ::view-transition-group(root) {
        animation-duration: 0.7s;
        animation-timing-function: var(--expo-out);
      }
            
      ::view-transition-new(root) {
        animation-name: reveal-light${blur ? "-blur" : ""};
        ${blur ? "filter: blur(2px);" : ""}
      }

      ::view-transition-old(root),
      .dark::view-transition-old(root) {
        animation: none;
        z-index: -1;
      }
      .dark::view-transition-new(root) {
        animation-name: reveal-dark${blur ? "-blur" : ""};
        ${blur ? "filter: blur(2px);" : ""}
      }

      @keyframes reveal-dark${blur ? "-blur" : ""} {
        from {
          clip-path: circle(0% at 50% 50%);
          ${blur ? "filter: blur(8px);" : ""}
        }
        ${blur ? "50% { filter: blur(4px); }" : ""}
        to {
          clip-path: circle(100.0% at 50% 50%);
          ${blur ? "filter: blur(0px);" : ""}
        }
      }

      @keyframes reveal-light${blur ? "-blur" : ""} {
        from {
           clip-path: circle(0% at 50% 50%);
           ${blur ? "filter: blur(8px);" : ""}
        }
        ${blur ? "50% { filter: blur(4px); }" : ""}
        to {
          clip-path: circle(100.0% at 50% 50%);
          ${blur ? "filter: blur(0px);" : ""}
        }
      }
      `,
		};
	}
	if (variant === "gif") {
		return {
			name: `${variant}-${start}`,
			css: `
      ::view-transition-group(root) {
  animation-timing-function: var(--expo-in);
}

::view-transition-new(root) {
  mask: url('${url}') center / 0 no-repeat;
  animation: scale 3s;
}

::view-transition-old(root),
.dark::view-transition-old(root) {
  animation: scale 3s;
}

@keyframes scale {
  0% {
    mask-size: 0;
  }
  10% {
    mask-size: 50vmax;
  }
  90% {
    mask-size: 50vmax;
  }
  100% {
    mask-size: 2000vmax;
  }
}`,
		};
	}

	if (variant === "circle-blur") {
		if (start === "center") {
			return {
				name: `${variant}-${start}`,
				css: `
        ::view-transition-group(root) {
          animation-timing-function: var(--expo-out);
        }

        ::view-transition-new(root) {
          mask: url('${svg}') center / 0 no-repeat;
          mask-origin: content-box;
          animation: scale 1s;
          transform-origin: center;
        }

        ::view-transition-old(root),
        .dark::view-transition-old(root) {
          animation: scale 1s;
          transform-origin: center;
          z-index: -1;
        }

        @keyframes scale {
          to {
            mask-size: 350vmax;
          }
        }
        `,
			};
		}

		return {
			name: `${variant}-${start}`,
			css: `
      ::view-transition-group(root) {
        animation-timing-function: var(--expo-out);
      }

      ::view-transition-new(root) {
        mask: url('${svg}') ${start.replace("-", " ")} / 0 no-repeat;
        mask-origin: content-box;
        animation: scale 1s;
        transform-origin: ${transformOrigin};
      }

      ::view-transition-old(root),
      .dark::view-transition-old(root) {
        animation: scale 1s;
        transform-origin: ${transformOrigin};
        z-index: -1;
      }

      @keyframes scale {
        to {
          mask-size: 350vmax;
        }
      }
      `,
		};
	}

	if (variant === "polygon") {
		const getPolygonClipPaths = (position: AnimationStart) => {
			switch (position) {
				case "top-left":
					return {
						darkFrom: "polygon(50% -71%, -50% 71%, -50% 71%, 50% -71%)",
						darkTo: "polygon(50% -71%, -50% 71%, 50% 171%, 171% 50%)",
						lightFrom: "polygon(171% 50%, 50% 171%, 50% 171%, 171% 50%)",
						lightTo: "polygon(171% 50%, 50% 171%, -50% 71%, 50% -71%)",
					};
				case "top-right":
					return {
						darkFrom: "polygon(150% -71%, 250% 71%, 250% 71%, 150% -71%)",
						darkTo: "polygon(150% -71%, 250% 71%, 50% 171%, -71% 50%)",
						lightFrom: "polygon(-71% 50%, 50% 171%, 50% 171%, -71% 50%)",
						lightTo: "polygon(-71% 50%, 50% 171%, 250% 71%, 150% -71%)",
					};
				default:
					return {
						darkFrom: "polygon(50% -71%, -50% 71%, -50% 71%, 50% -71%)",
						darkTo: "polygon(50% -71%, -50% 71%, 50% 171%, 171% 50%)",
						lightFrom: "polygon(171% 50%, 50% 171%, 50% 171%, 171% 50%)",
						lightTo: "polygon(171% 50%, 50% 171%, -50% 71%, 50% -71%)",
					};
			}
		};

		const clipPaths = getPolygonClipPaths(start);

		return {
			name: `${variant}-${start}${blur ? "-blur" : ""}`,
			css: `
      ::view-transition-group(root) {
        animation-duration: 0.7s;
        animation-timing-function: var(--expo-out);
      }
            
      ::view-transition-new(root) {
        animation-name: reveal-light-${start}${blur ? "-blur" : ""};
        ${blur ? "filter: blur(2px);" : ""}
      }

      ::view-transition-old(root),
      .dark::view-transition-old(root) {
        animation: none;
        z-index: -1;
      }
      .dark::view-transition-new(root) {
        animation-name: reveal-dark-${start}${blur ? "-blur" : ""};
        ${blur ? "filter: blur(2px);" : ""}
      }

      @keyframes reveal-dark-${start}${blur ? "-blur" : ""} {
        from {
          clip-path: ${clipPaths.darkFrom};
          ${blur ? "filter: blur(8px);" : ""}
        }
        ${blur ? "50% { filter: blur(4px); }" : ""}
        to {
          clip-path: ${clipPaths.darkTo};
          ${blur ? "filter: blur(0px);" : ""}
        }
      }

      @keyframes reveal-light-${start}${blur ? "-blur" : ""} {
        from {
          clip-path: ${clipPaths.lightFrom};
          ${blur ? "filter: blur(8px);" : ""}
        }
        ${blur ? "50% { filter: blur(4px); }" : ""}
        to {
          clip-path: ${clipPaths.lightTo};
          ${blur ? "filter: blur(0px);" : ""}
        }
      }
      `,
		};
	}

	// Handle circle variants with start positions using clip-path
	if (variant === "circle" && start !== "center") {
		const getClipPathPosition = (position: AnimationStart) => {
			switch (position) {
				case "top-left":
					return "0% 0%";
				case "top-right":
					return "100% 0%";
				case "bottom-left":
					return "0% 100%";
				case "bottom-right":
					return "100% 100%";
				case "top-center":
					return "50% 0%";
				case "bottom-center":
					return "50% 100%";
				default:
					return "50% 50%";
			}
		};

		const clipPosition = getClipPathPosition(start);

		return {
			name: `${variant}-${start}${blur ? "-blur" : ""}`,
			css: `
       ::view-transition-group(root) {
        animation-duration: 1s;
        animation-timing-function: var(--expo-out);
      }
            
      ::view-transition-new(root) {
        animation-name: reveal-light-${start}${blur ? "-blur" : ""};
        ${blur ? "filter: blur(2px);" : ""}
      }

      ::view-transition-old(root),
      .dark::view-transition-old(root) {
        animation: none;
        z-index: -1;
      }
      .dark::view-transition-new(root) {
        animation-name: reveal-dark-${start}${blur ? "-blur" : ""};
        ${blur ? "filter: blur(2px);" : ""}
      }

      @keyframes reveal-dark-${start}${blur ? "-blur" : ""} {
        from {
          clip-path: circle(0% at ${clipPosition});
          ${blur ? "filter: blur(8px);" : ""}
        }
        ${blur ? "50% { filter: blur(4px); }" : ""}
        to {
          clip-path: circle(150.0% at ${clipPosition});
          ${blur ? "filter: blur(0px);" : ""}
        }
      }

      @keyframes reveal-light-${start}${blur ? "-blur" : ""} {
        from {
           clip-path: circle(0% at ${clipPosition});
           ${blur ? "filter: blur(8px);" : ""}
        }
        ${blur ? "50% { filter: blur(4px); }" : ""}
        to {
          clip-path: circle(150.0% at ${clipPosition});
          ${blur ? "filter: blur(0px);" : ""}
        }
      }
      `,
		};
	}

	return {
		name: `${variant}-${start}${blur ? "-blur" : ""}`,
		css: `
      ::view-transition-group(root) {
        animation-timing-function: var(--expo-in);
      }
      ::view-transition-new(root) {
        mask: url('${svg}') ${start.replace("-", " ")} / 0 no-repeat;
        mask-origin: content-box;
        animation: scale-${start}${blur ? "-blur" : ""} 1s;
        transform-origin: ${transformOrigin};
        ${blur ? "filter: blur(2px);" : ""}
      }
      ::view-transition-old(root),
      .dark::view-transition-old(root) {
        animation: scale-${start}${blur ? "-blur" : ""} 1s;
        transform-origin: ${transformOrigin};
        z-index: -1;
      }
      @keyframes scale-${start}${blur ? "-blur" : ""} {
        from {
          ${blur ? "filter: blur(8px);" : ""}
        }
        ${blur ? "50% { filter: blur(4px); }" : ""}
        to {
          mask-size: 2000vmax;
          ${blur ? "filter: blur(0px);" : ""}
        }
      }
    `,
	};
};

// ///////////////////////////////////////////////////////////////////////////
// Custom hook for theme toggle functionality
export const useThemeToggle = ({
	variant = "circle",
	start = "center",
	blur = false,
	gifUrl = "",
}: {
	variant?: AnimationVariant;
	start?: AnimationStart;
	blur?: boolean;
	gifUrl?: string;
} = {}) => {
	const { theme, setTheme, resolvedTheme } = useTheme();

	const [isDark, setIsDark] = useState(false);

	// Sync isDark state with resolved theme after hydration
	useEffect(() => {
		setIsDark(resolvedTheme === "dark");
	}, [resolvedTheme]);

	const styleId = "theme-transition-styles";

	const updateStyles = useCallback((css: string) => {
		if (typeof window === "undefined") return;

		let styleElement = document.getElementById(styleId) as HTMLStyleElement;

		if (!styleElement) {
			styleElement = document.createElement("style");
			styleElement.id = styleId;
			document.head.appendChild(styleElement);
		}

		styleElement.textContent = css;
	}, []);

	const toggleTheme = useCallback(() => {
		setIsDark(!isDark);

		const animation = createAnimation(variant, start, blur, gifUrl);

		updateStyles(animation.css);

		if (typeof window === "undefined") return;

		const switchTheme = () => {
			setTheme(theme === "light" ? "dark" : "light");
		};

		if (!document.startViewTransition) {
			switchTheme();
			return;
		}

		document.startViewTransition(switchTheme);
	}, [theme, setTheme, variant, start, blur, gifUrl, updateStyles, isDark]);

	const setCrazyLightTheme = useCallback(() => {
		setIsDark(false);

		const animation = createAnimation(variant, start, blur, gifUrl);

		updateStyles(animation.css);

		if (typeof window === "undefined") return;

		const switchTheme = () => {
			setTheme("light");
		};

		if (!document.startViewTransition) {
			switchTheme();
			return;
		}

		document.startViewTransition(switchTheme);
	}, [setTheme, variant, start, blur, gifUrl, updateStyles]);

	const setCrazyDarkTheme = useCallback(() => {
		setIsDark(true);

		const animation = createAnimation(variant, start, blur, gifUrl);

		updateStyles(animation.css);

		if (typeof window === "undefined") return;

		const switchTheme = () => {
			setTheme("dark");
		};

		if (!document.startViewTransition) {
			switchTheme();
			return;
		}

		document.startViewTransition(switchTheme);
	}, [setTheme, variant, start, blur, gifUrl, updateStyles]);

	const setCrazySystemTheme = useCallback(() => {
		if (typeof window === "undefined") return;

		const prefersDark = window.matchMedia("(prefers-color-scheme: dark)").matches;
		setIsDark(prefersDark);

		const animation = createAnimation(variant, start, blur, gifUrl);

		updateStyles(animation.css);

		const switchTheme = () => {
			setTheme("system");
		};

		if (!document.startViewTransition) {
			switchTheme();
			return;
		}

		document.startViewTransition(switchTheme);
	}, [setTheme, variant, start, blur, gifUrl, updateStyles]);

	return {
		isDark,
		setIsDark,
		toggleTheme,
		setCrazyLightTheme,
		setCrazyDarkTheme,
		setCrazySystemTheme,
	};
};

// ///////////////////////////////////////////////////////////////////////////
// Theme Toggle Button Component (Sun/Moon Style)

export const ThemeToggleButton = ({
	className = "",
	variant = "circle",
	start = "center",
	blur = false,
	gifUrl = "",
}: {
	className?: string;
	variant?: AnimationVariant;
	start?: AnimationStart;
	blur?: boolean;
	gifUrl?: string;
}) => {
	const { isDark, toggleTheme } = useThemeToggle({
		variant,
		start,
		blur,
		gifUrl,
	});
	const clipId = useId();
	const clipPathId = `theme-toggle-clip-${clipId}`;

	return (
		<button
			type="button"
			className={cn(
				"size-10 cursor-pointer rounded-full p-2 transition-all duration-300 active:scale-95 bg-transparent",
				isDark ? "text-white" : "text-black",
				className
			)}
			onClick={toggleTheme}
			aria-label="Toggle theme"
		>
			<span className="sr-only">Toggle theme</span>
			<svg
				xmlns="http://www.w3.org/2000/svg"
				aria-hidden="true"
				fill="currentColor"
				strokeLinecap="round"
				viewBox="0 0 32 32"
			>
				<clipPath id={clipPathId}>
					<motion.path
						animate={{ y: isDark ? 10 : 0, x: isDark ? -12 : 0 }}
						transition={{ ease: "easeInOut", duration: 0.35 }}
						d="M0-5h30a1 1 0 0 0 9 13v24H0Z"
					/>
				</clipPath>
				<g clipPath={`url(#${clipPathId})`}>
					<motion.circle
						animate={{ r: isDark ? 10 : 8 }}
						transition={{ ease: "easeInOut", duration: 0.35 }}
						cx="16"
						cy="16"
					/>
					<motion.g
						animate={{
							rotate: isDark ? -100 : 0,
							scale: isDark ? 0.5 : 1,
							opacity: isDark ? 0 : 1,
						}}
						transition={{ ease: "easeInOut", duration: 0.35 }}
						stroke="currentColor"
						strokeWidth="1.5"
					>
						<path d="M16 5.5v-4" />
						<path d="M16 30.5v-4" />
						<path d="M1.5 16h4" />
						<path d="M26.5 16h4" />
						<path d="m23.4 8.6 2.8-2.8" />
						<path d="m5.7 26.3 2.9-2.9" />
						<path d="m5.8 5.8 2.8 2.8" />
						<path d="m23.4 23.4 2.9 2.9" />
					</motion.g>
				</g>
			</svg>
		</button>
	);
};

// ///////////////////////////////////////////////////////////////////////////
// Backwards compatible export (alias for ThemeToggleButton with default settings)
export function ThemeTogglerComponent() {
	return <ThemeToggleButton variant="circle" start="top-right" className="size-8" />;
}

/**
 * Skiper 26 Theme_buttons_002 — React + CSS + transition view api  https://developer.chrome.com/docs/web-platform/view-transitions/
 * Original concept from rudrodip
 * Inspired by from https://github.com/rudrodip/theme-toggle-effect
 * We respect the original creators. This is an inspired rebuild with our own taste and does not claim any ownership.
 * These animations aren't associated with the rudrodip . They're independent recreations meant to study interaction design
 *
 * License & Usage:
 * - Free to use and modify in both personal and commercial projects.
 * - Attribution to Skiper UI is required when using the free version.
 * - No attribution required with Skiper UI Pro.
 *
 * Feedback and contributions are welcome.
 *
 * Author: @gurvinder-singh02
 * Website: https://gxuri.in
 * Twitter: https://x.com/Gur__vi
 */