import { alpha, createTheme, Theme as MuiTheme, Shadows } from "@mui/material";
import {
  getCurrentWebviewWindow,
  WebviewWindow,
} from "@tauri-apps/api/webviewWindow";
import { Theme as TauriOsTheme } from "@tauri-apps/api/window";
import { useEffect, useMemo } from "react";

import { useVerge } from "@/hooks/use-verge";
import { defaultDarkTheme, defaultTheme } from "@/pages/_theme";
import { useSetThemeMode, useThemeMode } from "@/services/states";

const CSS_INJECTION_SCOPE_ROOT = "[data-css-injection-root]";
const CSS_INJECTION_SCOPE_LIMIT =
  ':is(.monaco-editor .view-lines, .monaco-editor .view-line, .monaco-editor .margin, .monaco-editor .margin-view-overlays, .monaco-editor .view-overlays, .monaco-editor [class^="mtk"], .monaco-editor [class*=" mtk"])';
const TOP_LEVEL_AT_RULES = [
  "@charset",
  "@import",
  "@namespace",
  "@font-face",
  "@keyframes",
  "@counter-style",
  "@page",
  "@property",
  "@font-feature-values",
  "@color-profile",
];
let cssScopeSupport: boolean | null = null;

const canUseCssScope = () => {
  if (cssScopeSupport !== null) {
    return cssScopeSupport;
  }
  try {
    const testStyle = document.createElement("style");
    testStyle.textContent = "@scope (:root) { }";
    document.head.appendChild(testStyle);
    cssScopeSupport = !!testStyle.sheet?.cssRules?.length;
    document.head.removeChild(testStyle);
  } catch {
    cssScopeSupport = false;
  }
  return cssScopeSupport;
};

const wrapCssInjectionWithScope = (css?: string) => {
  if (!css?.trim()) {
    return "";
  }
  const lowerCss = css.toLowerCase();
  const hasTopLevelOnlyRule = TOP_LEVEL_AT_RULES.some((rule) =>
    lowerCss.includes(rule),
  );
  if (hasTopLevelOnlyRule) {
    return null;
  }
  const scopeRoot = CSS_INJECTION_SCOPE_ROOT;
  const scopeLimit = CSS_INJECTION_SCOPE_LIMIT;
  const scopedBlock = `@scope (${scopeRoot}) to (${scopeLimit}) {
${css}
}`;
  return scopedBlock;
};

/**
 * custom theme
 */
export const useCustomTheme = () => {
  const appWindow: WebviewWindow = useMemo(() => getCurrentWebviewWindow(), []);
  const { verge } = useVerge();
  const { theme_mode, theme_setting } = verge ?? {};
  const mode = useThemeMode();
  const setMode = useSetThemeMode();
  const userBackgroundImage = theme_setting?.background_image || "";
  const hasUserBackground = !!userBackgroundImage;

  useEffect(() => {
    if (theme_mode === "light" || theme_mode === "dark") {
      setMode(theme_mode);
    }
  }, [theme_mode, setMode]);

  useEffect(() => {
    if (theme_mode !== "system") {
      return;
    }

    let isMounted = true;

    const timerId = setTimeout(() => {
      if (!isMounted) return;
      appWindow
        .theme()
        .then((systemTheme) => {
          if (isMounted && systemTheme) {
            setMode(systemTheme);
          }
        })
        .catch((err) => {
          console.error("Failed to get initial system theme:", err);
        });
    }, 0);

    const unlistenPromise = appWindow.onThemeChanged(({ payload }) => {
      if (isMounted) {
        setMode(payload);
      }
    });

    return () => {
      isMounted = false;
      clearTimeout(timerId);
      unlistenPromise
        .then((unlistenFn) => {
          if (typeof unlistenFn === "function") {
            unlistenFn();
          }
        })
        .catch((err) => {
          console.error("Failed to unlisten from theme changes:", err);
        });
    };
  }, [theme_mode, appWindow, setMode]);

  useEffect(() => {
    if (theme_mode === undefined) {
      return;
    }

    if (theme_mode === "system") {
      appWindow.setTheme(null).catch((err) => {
        console.error(
          "Failed to set window theme to follow system (setTheme(null)):",
          err,
        );
      });
    } else if (mode) {
      appWindow.setTheme(mode as TauriOsTheme).catch((err) => {
        console.error(`Failed to set window theme to ${mode}:`, err);
      });
    }
  }, [mode, appWindow, theme_mode]);

  const theme = useMemo(() => {
    const setting = theme_setting || {};
    const dt = mode === "light" ? defaultTheme : defaultDarkTheme;
    let muiTheme: MuiTheme;

    try {
      muiTheme = createTheme({
        breakpoints: {
          values: { xs: 0, sm: 650, md: 900, lg: 1200, xl: 1536 },
        },
        palette: {
          mode,
          primary: { main: setting.primary_color || dt.primary_color },
          secondary: { main: setting.secondary_color || dt.secondary_color },
          info: { main: setting.info_color || dt.info_color },
          error: { main: setting.error_color || dt.error_color },
          warning: { main: setting.warning_color || dt.warning_color },
          success: { main: setting.success_color || dt.success_color },
          text: {
            primary: setting.primary_text || dt.primary_text,
            secondary: setting.secondary_text || dt.secondary_text,
          },
          background: {
            paper: dt.background_color,
            default: dt.background_color,
          },
        },
        shadows: Array(25).fill("none") as Shadows,
        typography: {
          fontFamily: setting.font_family
            ? `${setting.font_family}, ${dt.font_family}`
            : dt.font_family,
        },
      });
    } catch (e) {
      console.error("Error creating MUI theme, falling back to defaults:", e);
      muiTheme = createTheme({
        breakpoints: {
          values: { xs: 0, sm: 650, md: 900, lg: 1200, xl: 1536 },
        },
        palette: {
          mode,
          primary: { main: dt.primary_color },
          secondary: { main: dt.secondary_color },
          info: { main: dt.info_color },
          error: { main: dt.error_color },
          warning: { main: dt.warning_color },
          success: { main: dt.success_color },
          text: { primary: dt.primary_text, secondary: dt.secondary_text },
          background: {
            paper: dt.background_color,
            default: dt.background_color,
          },
        },
        typography: { fontFamily: dt.font_family },
      });
    }

    const rootEle = document.documentElement;
    if (rootEle) {
      const backgroundColor =
        mode === "light" ? "#ECECEC" : dt.background_color;
      const selectColor = mode === "light" ? "#f5f5f5" : "#3E3E3E";
      const scrollColor = mode === "light" ? "#90939980" : "#555555";
      const dividerColor =
        mode === "light" ? "rgba(0, 0, 0, 0.06)" : "rgba(255, 255, 255, 0.06)";
      rootEle.style.setProperty("--divider-color", dividerColor);
      rootEle.style.setProperty("--background-color", backgroundColor);
      rootEle.style.setProperty("--selection-color", selectColor);
      rootEle.style.setProperty("--scroller-color", scrollColor);
      rootEle.style.setProperty(
        "--primary-main",
        muiTheme.palette.primary.main,
      );
      rootEle.style.setProperty(
        "--background-color-alpha",
        alpha(muiTheme.palette.primary.main, 0.1),
      );
      rootEle.style.setProperty(
        "--window-border-color",
        mode === "light" ? "#cccccc" : "#1E1E1E",
      );
      rootEle.style.setProperty(
        "--scrollbar-bg",
        mode === "light" ? "#f1f1f1" : "#2E303D",
      );
      rootEle.style.setProperty(
        "--scrollbar-thumb",
        mode === "light" ? "#c1c1c1" : "#555555",
      );
      rootEle.style.setProperty(
        "--user-background-image",
        hasUserBackground ? `url('${userBackgroundImage}')` : "none",
      );
      rootEle.style.setProperty(
        "--background-blend-mode",
        setting.background_blend_mode || "normal",
      );
      rootEle.style.setProperty(
        "--background-opacity",
        setting.background_opacity !== undefined
          ? String(setting.background_opacity)
          : "1",
      );
      rootEle.setAttribute("data-css-injection-root", "true");
    }

    let styleElement = document.querySelector("style#verge-theme");
    if (!styleElement) {
      styleElement = document.createElement("style");
      styleElement.id = "verge-theme";
      document.head.appendChild(styleElement!);
    }

    if (styleElement) {
      let scopedCss: string | null = null;
      if (canUseCssScope() && setting.css_injection) {
        scopedCss = wrapCssInjectionWithScope(setting.css_injection);
      }
      const effectiveInjectedCss = scopedCss ?? setting.css_injection ?? "";
      const globalStyles = `
        /* 修复滚动条样式 */
        ::-webkit-scrollbar {
          width: 8px;
          height: 8px;
          background-color: var(--scrollbar-bg);
        }
        ::-webkit-scrollbar-thumb {
          background-color: var(--scrollbar-thumb);
          border-radius: 4px;
        }
        ::-webkit-scrollbar-thumb:hover {
          background-color: ${mode === "light" ? "#a1a1a1" : "#666666"};
        }

        /* 背景图处理 */
        body {
          background-color: var(--background-color);
          ${
            hasUserBackground
              ? `
            background-image: var(--user-background-image);
            background-size: cover;
            background-position: center;
            background-attachment: fixed;
            background-blend-mode: var(--background-blend-mode);
            opacity: var(--background-opacity);
          `
              : ""
          }
        }

        /* 修复可能的白色边框 */
        .MuiPaper-root {
          border-color: var(--window-border-color) !important;
        }

        /* 确保模态框和对话框也使用暗色主题 */
        .MuiDialog-paper {
          background-color: ${mode === "light" ? "#ffffff" : "#2E303D"} !important;
        }

        /* 移除可能的白色点或线条 */
        * {
          outline: none !important;
          box-shadow: none !important;
        }
      `;

      styleElement.innerHTML = effectiveInjectedCss + globalStyles;
    }

    const { palette } = muiTheme;
    setTimeout(() => {
      const dom = document.querySelector("#Gradient2");
      if (dom) {
        dom.innerHTML = `
        <stop offset="0%" stop-color="${palette.primary.main}" />
        <stop offset="80%" stop-color="${palette.primary.dark}" />
        <stop offset="100%" stop-color="${palette.primary.dark}" />
        `;
      }
    }, 0);

    return muiTheme;
  }, [mode, theme_setting, userBackgroundImage, hasUserBackground]);

  return { theme };
};