"use client"

import * as React from "react"
import { useState, useEffect } from "react";
import { PopoverProps } from "@radix-ui/react-popover"

import { Check, CaretUpDown } from "@phosphor-icons/react";

import { cn } from "@/lib/utils"
import { useIsMobileWidth, useMutationObserver } from "@/app/common/utils";
import { Button } from "@/components/ui/button";
import {
    Command,
    CommandEmpty,
    CommandGroup,
    CommandInput,
    CommandItem,
    CommandList,
} from "@/components/ui/command";
import {
    Popover,
    PopoverContent,
    PopoverTrigger,
} from "@/components/ui/popover";

import { ModelOptions, useUserConfig } from "./auth";
import { HoverCard, HoverCardContent, HoverCardTrigger } from "@/components/ui/hover-card";
import { Skeleton } from "@/components/ui/skeleton";

interface ModelSelectorProps extends PopoverProps {
    onSelect: (model: ModelOptions) => void;
    disabled?: boolean;
    initialModel?: string;
}

export function ModelSelector({ ...props }: ModelSelectorProps) {
    const [open, setOpen] = React.useState(false)
    const [peekedModel, setPeekedModel] = useState<ModelOptions | undefined>(undefined);
    const [selectedModel, setSelectedModel] = useState<ModelOptions | undefined>(undefined);
    const { data: userConfig, error, isLoading: isLoadingUserConfig } = useUserConfig(true);
    const [models, setModels] = useState<ModelOptions[]>([]);
    const isMobileWidth = useIsMobileWidth();

    useEffect(() => {
        if (isLoadingUserConfig) return;

        if (userConfig) {
            setModels(userConfig.chat_model_options);
            if (!props.initialModel) {
                const selectedChatModelOption = userConfig.chat_model_options.find(model => model.id === userConfig.selected_chat_model_config);
                if (!selectedChatModelOption && userConfig.chat_model_options.length > 0) {
                    setSelectedModel(userConfig.chat_model_options[0]);
                } else {
                    setSelectedModel(selectedChatModelOption);
                }
            } else {
                const model = userConfig.chat_model_options.find(model => model.name === props.initialModel);
                setSelectedModel(model);
            }
        }
    }, [userConfig, props.initialModel, isLoadingUserConfig]);

    useEffect(() => {
        if (selectedModel && userConfig) {
            props.onSelect(selectedModel);
        }
    }, [selectedModel, userConfig, props.onSelect]);

    if (isLoadingUserConfig) {
        return (
            <Skeleton className="w-full h-10" />
        );
    }

    if (error) {
        return (
            <div className="text-sm text-error">{error.message}</div>
        );
    }

    return (
        <div className="grid gap-2 w-[250px]">
            <Popover open={open} onOpenChange={setOpen} {...props}>
                <PopoverTrigger asChild>
                    <Button
                        variant="outline"
                        role="combobox"
                        aria-expanded={open}
                        aria-label="Select a model"
                        className="w-full justify-between text-left"
                        disabled={props.disabled ?? false}
                    >
                        <p className="truncate">
                            {selectedModel ? selectedModel.name.substring(0, 20) : "Select a model..."}
                        </p>
                        <CaretUpDown className="opacity-50" />
                    </Button>
                </PopoverTrigger>
                <PopoverContent align="end" className="w-[250px] p-0">
                    {
                        isMobileWidth ?
                            <div>
                                <Command loop>
                                    <CommandList className="h-[var(--cmdk-list-height)]">
                                        <CommandInput placeholder="Search Models..." />
                                        <CommandEmpty>No Models found.</CommandEmpty>
                                        <CommandGroup key={"models"} heading={"Models"}>
                                            {models && models.length > 0 && models
                                                .map((model) => (
                                                    <ModelItem
                                                        key={model.id}
                                                        model={model}
                                                        isSelected={selectedModel?.id === model.id}
                                                        onPeek={(model) => setPeekedModel(model)}
                                                        onSelect={() => {
                                                            setSelectedModel(model)
                                                            setOpen(false)
                                                        }}
                                                    />
                                                ))}
                                        </CommandGroup>
                                    </CommandList>
                                </Command>
                            </div>
                            :
                            <HoverCard>
                                <HoverCardContent
                                    side="left"
                                    align="start"
                                    forceMount
                                    className="min-h-[280px]"
                                >
                                    <div className="grid gap-2">
                                        <h4 className="font-medium leading-none">{peekedModel?.name}</h4>
                                        <div className="text-sm text-muted-foreground">
                                            {peekedModel?.description}
                                        </div>
                                        {peekedModel?.strengths ? (
                                            <div className="mt-4 grid gap-2">
                                                <h5 className="text-sm font-medium leading-none">
                                                    Strengths
                                                </h5>
                                                <p className="text-sm text-muted-foreground">
                                                    {peekedModel.strengths}
                                                </p>
                                            </div>
                                        ) : null}
                                    </div>
                                </HoverCardContent>
                                <div>
                                    <HoverCardTrigger />
                                    <Command loop>
                                        <CommandList className="h-[var(--cmdk-list-height)]">
                                            <CommandInput placeholder="Search Models..." />
                                            <CommandEmpty>No Models found.</CommandEmpty>
                                            <CommandGroup key={"models"} heading={"Models"}>
                                                {models && models.length > 0 && models
                                                    .map((model) => (
                                                        <ModelItem
                                                            key={model.id}
                                                            model={model}
                                                            isSelected={selectedModel?.id === model.id}
                                                            onPeek={(model) => setPeekedModel(model)}
                                                            onSelect={() => {
                                                                setSelectedModel(model)
                                                                setOpen(false)
                                                            }}
                                                        />
                                                    ))}
                                            </CommandGroup>
                                        </CommandList>
                                    </Command>
                                </div>
                            </HoverCard>
                    }
                </PopoverContent>
            </Popover>
        </div>
    )
}

interface ModelItemProps {
    model: ModelOptions,
    isSelected: boolean,
    onSelect: () => void,
    onPeek: (model: ModelOptions) => void
}

function ModelItem({ model, isSelected, onSelect, onPeek }: ModelItemProps) {
    const ref = React.useRef<HTMLDivElement>(null)

    useMutationObserver(ref, (mutations) => {
        mutations.forEach((mutation) => {
            if (
                mutation.type === "attributes" &&
                mutation.attributeName === "aria-selected" &&
                ref.current?.getAttribute("aria-selected") === "true"
            ) {
                onPeek(model)
            }
        })
    })

    return (
        <CommandItem
            key={model.id}
            onSelect={onSelect}
            ref={ref}
            className="data-[selected=true]:bg-muted data-[selected=true]:text-secondary-foreground"
        >
            {model.name}
            <Check
                className={cn("ml-auto", isSelected ? "opacity-100" : "opacity-0")}
            />
        </CommandItem>
    )
}