"use client"

import { useId } from "react"
import { ChevronDownIcon, ChevronUpIcon, PlusIcon, Trash2Icon } from "lucide-react"
import { Button } from "@/components/ui/button"
import { Collapsible, CollapsibleContent, CollapsibleTrigger } from "@/components/ui/collapsible"
import { Field, FieldDescription, FieldLabel } from "@/components/ui/field"
import { Input } from "@/components/ui/input"
import { Textarea } from "@/components/ui/textarea"
import type { FieldDef, ListFieldDef, ListItem, TemplateData, TemplateDefinition } from "../../../lib/types"

const MAX_ITEMS = 40

export function ContentPanel({ def, data, hidden, onChange }: {
    def: TemplateDefinition
    data: TemplateData
    hidden: string[]
    onChange: (section: string, field: string, value: string | ListItem[]) => void
}) {
    return (
        <div className="flex flex-col gap-2">
            {def.sections.map((section, index) => (
                // Im Baukasten stehen die Bausteine im Vordergrund – „Marke & Kontakt“ startet zugeklappt
                <Collapsible key={section.key} defaultOpen={index === 0 && !def.builder} className="rounded-lg border">
                    <CollapsibleTrigger className="flex w-full cursor-pointer items-center justify-between gap-2 px-3 py-2.5 text-left text-sm font-medium [&[data-panel-open]>svg]:rotate-180">
                        <span className="flex items-center gap-2">
                            {section.label}
                            {hidden.includes(section.key) && (
                                <span className="rounded bg-surface px-1.5 py-0.5 text-[11px] font-normal text-muted-foreground">ausgeblendet</span>
                            )}
                        </span>
                        <ChevronDownIcon className="size-4 shrink-0 text-muted-foreground transition-transform" />
                    </CollapsibleTrigger>
                    <CollapsibleContent>
                        <div className="flex flex-col gap-4 border-t px-3 py-4">
                            {section.fields.map((field) =>
                                field.type === "list" ? (
                                    <ListEditor
                                        key={field.key}
                                        field={field}
                                        items={(data[section.key]?.[field.key] as ListItem[] | undefined) ?? []}
                                        onChange={(items) => onChange(section.key, field.key, items)}
                                    />
                                ) : (
                                    <FieldInput
                                        key={field.key}
                                        field={field}
                                        value={(data[section.key]?.[field.key] as string | undefined) ?? ""}
                                        onChange={(value) => onChange(section.key, field.key, value)}
                                    />
                                )
                            )}
                        </div>
                    </CollapsibleContent>
                </Collapsible>
            ))}
        </div>
    )
}

export function FieldInput({ field, value, onChange }: { field: FieldDef; value: string; onChange: (value: string) => void }) {
    const id = useId()

    return (
        <Field>
            <FieldLabel htmlFor={id}>{field.label}</FieldLabel>
            {field.type === "textarea" ? (
                <Textarea id={id} value={value} rows={3} onChange={(event) => onChange(event.target.value)} />
            ) : (
                <Input
                    id={id}
                    value={value}
                    type={field.type === "image" ? "url" : "text"}
                    placeholder={field.type === "image" ? "https://images.unsplash.com/…" : undefined}
                    onChange={(event) => onChange(event.target.value)}
                />
            )}
            {field.type === "image" && value && (
                <div aria-hidden className="h-20 rounded-md border bg-surface bg-cover bg-center" style={{ backgroundImage: `url("${value}")` }} />
            )}
            {field.hint && <FieldDescription>{field.hint}</FieldDescription>}
        </Field>
    )
}

export function ListEditor({ field, items, onChange }: { field: ListFieldDef; items: ListItem[]; onChange: (items: ListItem[]) => void }) {
    function update(index: number, key: string, value: string) {
        onChange(items.map((item, i) => (i === index ? { ...item, [key]: value } : item)))
    }

    function move(index: number, offset: number) {
        const next = [...items]
        const [item] = next.splice(index, 1)
        next.splice(index + offset, 0, item)
        onChange(next)
    }

    return (
        <div className="flex flex-col gap-2">
            <p className="text-sm font-medium">{field.label}</p>
            {items.map((item, index) => (
                <div key={index} className="rounded-md border bg-surface/50 p-3">
                    <div className="mb-2 flex items-center justify-between">
                        <span className="text-xs font-medium text-muted-foreground">{field.itemLabel} {index + 1}</span>
                        <div className="flex">
                            <Button variant="ghost" size="icon-sm" aria-label="Nach oben" disabled={index === 0} onClick={() => move(index, -1)}>
                                <ChevronUpIcon />
                            </Button>
                            <Button variant="ghost" size="icon-sm" aria-label="Nach unten" disabled={index === items.length - 1} onClick={() => move(index, 1)}>
                                <ChevronDownIcon />
                            </Button>
                            <Button variant="ghost" size="icon-sm" aria-label={`${field.itemLabel} entfernen`} onClick={() => onChange(items.filter((_, i) => i !== index))}>
                                <Trash2Icon />
                            </Button>
                        </div>
                    </div>
                    <div className="flex flex-col gap-3">
                        {field.fields.map((sub) => (
                            <FieldInput key={sub.key} field={sub} value={item[sub.key] ?? ""} onChange={(value) => update(index, sub.key, value)} />
                        ))}
                    </div>
                </div>
            ))}
            <Button
                variant="outline"
                size="sm"
                disabled={items.length >= MAX_ITEMS}
                onClick={() => onChange([...items, Object.fromEntries(field.fields.map((sub) => [sub.key, ""]))])}
            >
                <PlusIcon /> {field.itemLabel} hinzufügen
            </Button>
        </div>
    )
}