"use client"

import { useRef, useState } from "react"
import { useMutation } from "@tanstack/react-query"
import { toast } from "sonner"
import { useForm } from "react-hook-form"
import { zodResolver } from "@hookform/resolvers/zod"
import { z } from "zod"
import { UploadIcon } from "lucide-react"

import { Button } from "@/shared/components/ui/button"
import { Input } from "@/shared/components/ui/input"
import { Textarea } from "@/shared/components/ui/textarea"
import { Field, FieldLabel, FieldError } from "@/shared/components/ui/field"
import { useAuthApi } from "@/shared/useApi"

const schema = z.object({
    name: z.string().trim().min(1, "Name is required").max(150),
    issuer: z.string().trim().max(150).optional(),
    certificate_number: z.string().trim().max(100).optional(),
    issued_date: z.string().optional(),
    expiry_date: z.string().optional(),
    notes: z.string().max(2000).optional(),
})

type FormValues = z.infer<typeof schema>

export type EmployeeCertificationFormProps = {
    employeeId: string
    onSuccess?: () => void
    onCancel?: () => void
}

export function EmployeeCertificationForm({ employeeId, onSuccess, onCancel }: EmployeeCertificationFormProps) {
    const api = useAuthApi()
    const fileRef = useRef<HTMLInputElement | null>(null)
    const [file, setFile] = useState<File | null>(null)

    const {
        register,
        handleSubmit,
        formState: { errors },
        reset,
    } = useForm<FormValues>({
        resolver: zodResolver(schema),
        defaultValues: {
            name: "", issuer: "", certificate_number: "",
            issued_date: "", expiry_date: "", notes: "",
        },
    })

    const mutation = useMutation({
        mutationFn: (values: FormValues) => {
            const promise = api.employees.createCertification(employeeId, {
                name: values.name,
                issuer: values.issuer || undefined,
                certificate_number: values.certificate_number || undefined,
                issued_date: values.issued_date || undefined,
                expiry_date: values.expiry_date || undefined,
                notes: values.notes || undefined,
                file: file ?? undefined,
            })
            toast.promise(promise, {
                loading: "Saving certification...",
                success: "Certification added",
                error: (err: any) => err?.message ?? "Failed to save",
            })
            return promise
        },
        onSuccess: () => {
            reset()
            setFile(null)
            onSuccess?.()
        },
    })

    return (
        <form className="grid gap-4" onSubmit={handleSubmit((v) => mutation.mutate(v))}>
            <Field>
                <FieldLabel>Name</FieldLabel>
                <Input {...register("name")} placeholder="e.g. ASE A1 Engine Repair" />
                {errors.name && <FieldError>{errors.name.message}</FieldError>}
            </Field>

            <div className="grid gap-4 sm:grid-cols-2">
                <Field>
                    <FieldLabel>Issuer</FieldLabel>
                    <Input {...register("issuer")} placeholder="ASE / SAE / ..." />
                </Field>
                <Field>
                    <FieldLabel>Certificate Number</FieldLabel>
                    <Input {...register("certificate_number")} placeholder="Optional" />
                </Field>
            </div>

            <div className="grid gap-4 sm:grid-cols-2">
                <Field>
                    <FieldLabel>Issued Date</FieldLabel>
                    <Input type="date" {...register("issued_date")} />
                </Field>
                <Field>
                    <FieldLabel>Expiry Date</FieldLabel>
                    <Input type="date" {...register("expiry_date")} />
                </Field>
            </div>

            <Field>
                <FieldLabel>Attachment (optional)</FieldLabel>
                <div className="flex items-center gap-2">
                    <Button type="button" variant="outline" size="sm" onClick={() => fileRef.current?.click()}>
                        <UploadIcon className="size-4" />
                        Choose file
                    </Button>
                    <span className="text-sm text-muted-foreground">{file ? file.name : "No file selected"}</span>
                    <input
                        ref={fileRef}
                        type="file"
                        className="hidden"
                        accept=".pdf,.jpg,.jpeg,.png,.webp,.doc,.docx"
                        onChange={(e) => setFile(e.target.files?.[0] ?? null)}
                    />
                </div>
            </Field>

            <Field>
                <FieldLabel>Notes</FieldLabel>
                <Textarea rows={3} {...register("notes")} />
            </Field>

            <div className="flex justify-end gap-2">
                {onCancel && (
                    <Button type="button" variant="outline" onClick={onCancel}>Cancel</Button>
                )}
                <Button type="submit" disabled={mutation.isPending}>
                    {mutation.isPending ? "Saving..." : "Save Certification"}
                </Button>
            </div>
        </form>
    )
}