"use client"

import { AlertTriangle, Plus, Save } from "lucide-react"

import { Button } from "@/shared/components/ui/button"
import { Alert, AlertTitle } from "@/shared/components/ui/alert"
import { FieldGroup } from "@/shared/components/ui/field"
import {
    Rhform,
    RhfTextField,
    RhfSelectField,
    RhfTextareaField,
} from "@/shared/components/form"
import { RhfEmployeeSelectField } from "@/modules/employees/rhf-employee-select-field"
import { toast } from "sonner"
import { useAuthApi } from "@/shared/useApi"
import { useResourceForm } from "@/shared/hooks/use-resource-form"
import { useFormMutation } from "@/shared/hooks/use-form-mutation"
import { toRelation, toId } from "@/shared/lib/utils"
import { LEAVE_REQUEST_ROUTES } from "@garage/api"

import { z } from "zod"

const LEAVE_TYPES = ["annual", "sick", "unpaid", "maternity", "paternity", "other"] as const

const relationFieldSchema = z.object({ value: z.string(), label: z.string() }).nullable()

const schema = z.object({
    employee: relationFieldSchema.refine((v) => !!v?.value, "Employee is required"),
    leave_type: z.enum(LEAVE_TYPES),
    start_date: z.string().min(1, "Start date is required"),
    end_date: z.string().min(1, "End date is required"),
    reason: z.string().max(2000).optional(),
})

type LeaveFormValues = z.infer<typeof schema>

const DEFAULT_VALUES: LeaveFormValues = {
    employee: null,
    leave_type: "annual",
    start_date: "",
    end_date: "",
    reason: "",
}

const TYPE_SELECT_OPTIONS = LEAVE_TYPES.map((v) => ({
    value: v,
    label: v.replace(/^./, (c) => c.toUpperCase()),
}))

export type LeaveRequestFormProps = {
    resourceId?: string | null
    initialData?: unknown
    onSuccess?: () => void
    /** Pre-fill the employee select when opened from an employee detail page. */
    presetEmployee?: { id: number | string; label: string } | null
}

function mapToFormValues(data: unknown, preset?: { id: number | string; label: string } | null): LeaveFormValues {
    const d = (data as any)?.data ?? data ?? {}
    const empLabel = d.employee
        ? `${d.employee.first_name ?? ""} ${d.employee.last_name ?? ""}`.trim()
        : ""

    const formatDate = (v: unknown) => {
        if (!v || typeof v !== "string") return ""
        return v.length >= 10 ? v.slice(0, 10) : v
    }

    return {
        employee: d.employee_id
            ? toRelation(d.employee_id, empLabel || `Employee #${d.employee_id}`)
            : (preset ? toRelation(preset.id, preset.label) : null),
        leave_type: d.leave_type || "annual",
        start_date: formatDate(d.start_date),
        end_date: formatDate(d.end_date),
        reason: d.reason || "",
    }
}

export function LeaveRequestForm({ resourceId, initialData, onSuccess, presetEmployee }: LeaveRequestFormProps) {
    const api = useAuthApi()

    const { form, isEditing } = useResourceForm<LeaveFormValues, any>({
        schema,
        defaultValues: presetEmployee
            ? { ...DEFAULT_VALUES, employee: toRelation(presetEmployee.id, presetEmployee.label) }
            : DEFAULT_VALUES,
        resourceId,
        initialData,
        initialize: (id) => api.leaveRequests.show(id),
        queryKey: [LEAVE_REQUEST_ROUTES.BY_ID, resourceId],
        mapToFormValues: (data) => mapToFormValues(data, presetEmployee),
    })

    const { mutate, error, isPending } = useFormMutation(form, {
        mutationFn: (values: LeaveFormValues) => {
            const payload = {
                employee_id: toId(values.employee) ?? 0,
                leave_type: values.leave_type,
                start_date: values.start_date,
                end_date: values.end_date,
                reason: values.reason || undefined,
            }
            const promise = isEditing && resourceId
                ? api.leaveRequests.update(resourceId, payload)
                : api.leaveRequests.create(payload as any)
            toast.promise(promise, {
                loading: isEditing ? "Updating..." : "Submitting...",
                success: isEditing ? "Leave request updated" : "Leave request submitted",
                error: isEditing ? "Failed to update" : "Failed to submit",
            })
            return promise
        },
        onSuccess: () => {
            form.reset()
            onSuccess?.()
        },
    })

    return (
        <Rhform form={form} onSubmit={(values) => mutate(values)}>
            {error && (
                <Alert variant="destructive" className="mb-4">
                    <AlertTriangle className="me-2 h-4 w-4" />
                    <AlertTitle>{isEditing ? "Failed to update" : "Failed to submit"}</AlertTitle>
                    {error.message}
                </Alert>
            )}

            <FieldGroup>
                <RhfEmployeeSelectField name="employee" label="Employee" required />

                <div className="grid grid-cols-1 gap-4 sm:grid-cols-2">
                    <RhfSelectField
                        name="leave_type"
                        label="Leave Type"
                        placeholder="Select type"
                        options={TYPE_SELECT_OPTIONS}
                    />
                    <div />
                </div>

                <div className="grid grid-cols-1 gap-4 sm:grid-cols-2">
                    <RhfTextField name="start_date" label="Start Date" type="date" required />
                    <RhfTextField name="end_date" label="End Date" type="date" required />
                </div>

                <RhfTextareaField name="reason" label="Reason" rows={3} />

                <Button type="submit" variant="default" disabled={isPending}>
                    {isEditing ? <Save /> : <Plus />}
                    {isPending ? "Saving..." : (isEditing ? "Update" : "Submit Request")}
                </Button>
            </FieldGroup>
        </Rhform>
    )
}