import React, { useState } from "react";
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogHeader,
  DialogTitle,
} from "@/components/ui/dialog";
import { Card, CardContent } from "@/components/ui/card";
import { Button } from "@/components/ui/button";
import { Badge } from "@/components/ui/badge";
import { Separator } from "@/components/ui/separator";
import { ScrollArea } from "@/components/ui/scroll-area";
import {
  Settings,
  Palette,
  Monitor,
  Sun,
  Moon,
  Smartphone,
  Check,
  GitBranch,
  Layers,
  Brain,
  Zap,
  Clock,
  DollarSign,
} from "lucide-react";
import { useKGDisplayMode } from "@/context/KGDisplayModeContext";
import { useModelPreferences } from "@/hooks/useModelPreferences";
import { AVAILABLE_MODELS, ModelConfig } from "@/lib/models";

interface SettingsModalProps {
  open: boolean;
  onOpenChange: (open: boolean) => void;
}

type Theme = "light" | "dark" | "system";

export function SettingsModal({ open, onOpenChange }: SettingsModalProps) {
  const [activeSection, setActiveSection] = useState<string>("appearance");
  const [currentTheme, setCurrentTheme] = useState<Theme>("system");
  const { mode: kgDisplayMode, setMode: setKGDisplayMode } = useKGDisplayMode();
  const {
    selectedModel,
    currentModelConfig,
    updateModelPreference,
    isLoading,
  } = useModelPreferences();

  const handleThemeChange = (theme: Theme) => {
    setCurrentTheme(theme);

    // Apply theme to document
    const root = document.documentElement;
    if (theme === "dark") {
      root.classList.add("dark");
    } else if (theme === "light") {
      root.classList.remove("dark");
    } else {
      // System theme - detect user preference
      const prefersDark = window.matchMedia(
        "(prefers-color-scheme: dark)"
      ).matches;
      if (prefersDark) {
        root.classList.add("dark");
      } else {
        root.classList.remove("dark");
      }
    }

    // Save to localStorage
    localStorage.setItem("theme", theme);
  };

  React.useEffect(() => {
    // Load saved theme on mount
    const savedTheme = localStorage.getItem("theme") as Theme;
    if (savedTheme) {
      setCurrentTheme(savedTheme);
      handleThemeChange(savedTheme);
    }
  }, []);

  const themeOptions = [
    {
      id: "light" as Theme,
      name: "Light",
      description: "Light mode for bright environments",
      icon: Sun,
    },
    {
      id: "dark" as Theme,
      name: "Dark",
      description: "Dark mode for low-light environments",
      icon: Moon,
    },
    {
      id: "system" as Theme,
      name: "System",
      description: "Follows your system preference",
      icon: Monitor,
    },
  ];

  const sidebarSections = [
    {
      id: "appearance",
      name: "Appearance",
      icon: Palette,
    },
    {
      id: "models",
      name: "Models",
      icon: Brain,
    },
    {
      id: "general",
      name: "General",
      icon: Settings,
    },
  ];

  const getCostLevelColor = (costLevel: string) => {
    switch (costLevel) {
      case "low":
        return "text-green-600";
      case "medium":
        return "text-yellow-600";
      case "high":
        return "text-red-600";
      default:
        return "text-gray-600";
    }
  };

  const getSpeedIcon = (speed: string) => {
    switch (speed) {
      case "fast":
        return Zap;
      case "medium":
        return Clock;
      case "slow":
        return Brain;
      default:
        return Clock;
    }
  };

  const renderModelCard = (model: ModelConfig) => {
    const SpeedIcon = getSpeedIcon(model.speed);
    const isSelected = selectedModel === model.id;

    return (
      <Card
        key={model.id}
        className={`cursor-pointer transition-all duration-200 hover:shadow-md ${
          isSelected
            ? "ring-2 ring-primary border-primary bg-primary/5"
            : "border-border hover:border-primary/50"
        }`}
        onClick={() => updateModelPreference(model.id)}
      >
        <CardContent className="p-4">
          <div className="flex items-center justify-between">
            <div className="flex items-center gap-3">
              <div className="p-2 rounded-lg bg-muted">
                <Brain className="h-4 w-4" />
              </div>
              <div className="flex-1">
                <div className="flex items-center gap-2">
                  <h4 className="font-medium">{model.name}</h4>
                  {model.recommended && (
                    <Badge variant="secondary" className="text-xs">
                      Recommended
                    </Badge>
                  )}
                </div>
                <p className="text-sm text-muted-foreground mt-1">
                  {model.description}
                </p>
                <div className="flex items-center gap-4 mt-2">
                  <div className="flex items-center gap-1">
                    <SpeedIcon className="h-3 w-3 text-muted-foreground" />
                    <span className="text-xs text-muted-foreground capitalize">
                      {model.speed}
                    </span>
                  </div>
                  <div className="flex items-center gap-1">
                    <DollarSign
                      className={`h-3 w-3 ${getCostLevelColor(
                        model.costLevel
                      )}`}
                    />
                    <span
                      className={`text-xs capitalize ${getCostLevelColor(
                        model.costLevel
                      )}`}
                    >
                      {model.costLevel} cost
                    </span>
                  </div>
                  <span className="text-xs text-muted-foreground">
                    {model.contextWindow} context
                  </span>
                </div>
              </div>
            </div>
            {isSelected && (
              <div className="p-1 rounded-full bg-primary">
                <Check className="h-3 w-3 text-primary-foreground" />
              </div>
            )}
          </div>
        </CardContent>
      </Card>
    );
  };

  const renderModelsSection = () => (
    <div className="space-y-6">
      {isLoading ? (
        <div className="flex items-center justify-center p-8">
          <div className="w-6 h-6 border-2 border-primary border-t-transparent rounded-full animate-spin mr-3" />
          Loading model preferences...
        </div>
      ) : (
        <>
          {/* Current Model Indicator */}
          {currentModelConfig && (
            <div className="bg-primary/10 border border-primary/20 p-4 rounded-lg">
              <div className="flex items-center gap-3 mb-2">
                <div className="p-2 rounded-lg bg-primary/20">
                  <Check className="h-4 w-4 text-primary" />
                </div>
                <div>
                  <h4 className="font-medium text-primary">
                    Currently Selected
                  </h4>
                  <p className="text-sm text-muted-foreground">
                    Active for all new graph generations
                  </p>
                </div>
              </div>
              <div className="ml-11">
                <p className="font-medium">{currentModelConfig.name}</p>
                <p className="text-sm text-muted-foreground">
                  {currentModelConfig.description}
                </p>
              </div>
            </div>
          )}

          <div>
            <h3 className="text-lg font-semibold mb-4">Standard Models</h3>
            <div className="space-y-3">
              {AVAILABLE_MODELS.standard.map(renderModelCard)}
            </div>
          </div>

          <Separator />

          <div>
            <h3 className="text-lg font-semibold mb-4">Reasoning Models</h3>
            <p className="text-sm text-muted-foreground mb-4">
              Specialized models for complex analysis and multi-step reasoning
              tasks.
            </p>
            <div className="space-y-3">
              {AVAILABLE_MODELS.reasoning.map(renderModelCard)}
            </div>
          </div>

          <Separator />

          <div className="bg-muted/30 p-4 rounded-lg">
            <div className="flex items-center gap-2 mb-2">
              <Brain className="h-4 w-4 text-muted-foreground" />
              <span className="text-sm font-medium">Model Selection</span>
            </div>
            <p className="text-xs text-muted-foreground">
              Your selected model will be used for all knowledge graph
              extractions. Changes apply to new generations only.
            </p>
          </div>
        </>
      )}
    </div>
  );

  const renderAppearanceSection = () => (
    <div className="space-y-6">
      <div>
        <h3 className="text-lg font-semibold mb-4">Theme Selection</h3>
        <div className="grid grid-cols-1 gap-3">
          {themeOptions.map((option) => (
            <Card
              key={option.id}
              className={`cursor-pointer transition-all hover:shadow-md ${
                currentTheme === option.id
                  ? "ring-2 ring-primary bg-primary/5"
                  : "hover:bg-muted/50"
              }`}
              onClick={() => handleThemeChange(option.id)}
            >
              <CardContent className="p-4">
                <div className="flex items-center justify-between">
                  <div className="flex items-center gap-3">
                    <div className="p-2 rounded-lg bg-muted">
                      <option.icon className="h-4 w-4" />
                    </div>
                    <div>
                      <h4 className="font-medium">{option.name}</h4>
                      <p className="text-sm text-muted-foreground">
                        {option.description}
                      </p>
                    </div>
                  </div>
                  {currentTheme === option.id && (
                    <div className="p-1 rounded-full bg-primary">
                      <Check className="h-3 w-3 text-primary-foreground" />
                    </div>
                  )}
                </div>
              </CardContent>
            </Card>
          ))}
        </div>
      </div>

      <Separator />

      <div>
        <h3 className="text-lg font-semibold mb-4">Color Customization</h3>
        <div className="bg-muted/30 p-4 rounded-lg">
          <div className="flex items-center gap-2 mb-2">
            <Smartphone className="h-4 w-4 text-muted-foreground" />
            <span className="text-sm font-medium">Coming Soon</span>
            <Badge variant="secondary" className="text-xs">
              Future Update
            </Badge>
          </div>
          <p className="text-sm text-muted-foreground">
            Custom color themes and accent colors will be available in a future
            update.
          </p>
        </div>
      </div>
    </div>
  );

  const renderGeneralSection = () => (
    <div className="space-y-6">
      <div>
        <h3 className="text-lg font-semibold mb-4">Knowledge Graph Display</h3>
        <div className="grid grid-cols-1 gap-3">
          {[
            {
              id: "multiple" as const,
              name: "Multiple Knowledge Graphs",
              description:
                "Show all knowledge graphs for research and comparison",
              icon: Layers,
            },
            {
              id: "single" as const,
              name: "Single Knowledge Graph",
              description:
                "Show only the most recent/best knowledge graph per trace",
              icon: GitBranch,
            },
          ].map((option) => (
            <Card
              key={option.id}
              className={`cursor-pointer transition-all hover:shadow-md ${
                kgDisplayMode === option.id
                  ? "ring-2 ring-primary bg-primary/5"
                  : "hover:bg-muted/50"
              }`}
              onClick={() => setKGDisplayMode(option.id)}
            >
              <CardContent className="p-4">
                <div className="flex items-center justify-between">
                  <div className="flex items-center gap-3">
                    <div className="p-2 rounded-lg bg-muted">
                      <option.icon className="h-4 w-4" />
                    </div>
                    <div>
                      <h4 className="font-medium">{option.name}</h4>
                      <p className="text-sm text-muted-foreground">
                        {option.description}
                      </p>
                    </div>
                  </div>
                  {kgDisplayMode === option.id && (
                    <div className="p-1 rounded-full bg-primary">
                      <Check className="h-3 w-3 text-primary-foreground" />
                    </div>
                  )}
                </div>
              </CardContent>
            </Card>
          ))}
        </div>
      </div>

      <Separator />

      <div>
        <h3 className="text-lg font-semibold mb-4">Additional Settings</h3>
        <div className="bg-muted/30 p-4 rounded-lg">
          <div className="flex items-center gap-2 mb-2">
            <Settings className="h-4 w-4 text-muted-foreground" />
            <span className="text-sm font-medium">More Options</span>
            <Badge variant="secondary" className="text-xs">
              Coming Soon
            </Badge>
          </div>
          <p className="text-sm text-muted-foreground">
            More configuration options including language preferences, default
            views, and notification settings will be available soon.
          </p>
        </div>
      </div>
    </div>
  );

  const renderSection = () => {
    switch (activeSection) {
      case "appearance":
        return renderAppearanceSection();
      case "models":
        return renderModelsSection();
      case "general":
        return renderGeneralSection();
      default:
        return renderAppearanceSection();
    }
  };

  return (
    <Dialog open={open} onOpenChange={onOpenChange}>
      <DialogContent className="max-w-4xl max-h-[90vh] p-0">
        <DialogHeader className="p-6 pb-0">
          <DialogTitle className="text-2xl font-bold flex items-center gap-2">
            <Settings className="h-6 w-6" />
            Settings & Preferences
          </DialogTitle>
          <DialogDescription className="text-base">
            Customize your AgentGraph experience
          </DialogDescription>
        </DialogHeader>

        <div className="flex flex-1 min-h-0">
          {/* Navigation Sidebar */}
          <div className="w-64 border-r bg-muted/20 p-4">
            <nav className="space-y-2">
              {sidebarSections.map((section) => (
                <Button
                  key={section.id}
                  variant={activeSection === section.id ? "secondary" : "ghost"}
                  className="w-full justify-start gap-2 h-auto p-3"
                  onClick={() => setActiveSection(section.id)}
                >
                  <section.icon className="h-4 w-4" />
                  <span className="text-sm font-medium">{section.name}</span>
                </Button>
              ))}
            </nav>
          </div>

          {/* Content Area */}
          <div className="flex-1 min-w-0">
            <ScrollArea className="h-[70vh] p-6">{renderSection()}</ScrollArea>
          </div>
        </div>

        <Separator />

        <div className="p-6 pt-4 flex justify-between items-center">
          <div className="text-sm text-muted-foreground">
            Changes are saved automatically
          </div>
          <Button onClick={() => onOpenChange(false)}>Done</Button>
        </div>
      </DialogContent>
    </Dialog>
  );
}