"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 { Card, CardContent, CardHeader, CardTitle } from "@/shared/components/ui/card"
import {
    Rhform,
    RhfAsyncSelectField,
    RhfSelectField,
    RhfTextField,
    RhfTextareaField,
    RhfAutoGenerateField,
    RhfDateField,
} from "@/shared/components/form"
import { useResourceForm } from "@/shared/hooks/use-resource-form"
import { useFormMutation } from "@/shared/hooks/use-form-mutation"
import { getTodayDate, toId, toRelation } from "@/shared/lib/utils"
import { useAuthApi } from "@/shared/useApi"
import {
    BillStatus,
    DiscountType,
    BILL_ROUTES,
    DEPARTMENT_ROUTES,
    JOB_CARD_ROUTES,
    PAYMENT_TERM_ROUTES,
    PURCHASE_ORDER_ROUTES,
    VENDOR_ROUTES,
    TAX_ROUTES,
} from "@garage/api"
import { toast } from "sonner"
import { PartsSelectorField } from "@/modules/parts/parts-selector-field"
import { ServicesSelectorField } from "@/modules/services/services-selector-field"
import { ExpenseItemsSelectorField } from "@/modules/expense-items/expense-items-selector-field"
import { useFormContext } from "react-hook-form"

import { billFormSchema, type BillFormValues } from "./bill.schema"
import { BillFormSummary } from "./bill-form-summary"

export type BillFormProps = {
    resourceId?: string | null
    initialData?: unknown
    onSuccess?: () => void
}

const DEFAULT_VALUES: BillFormValues = {
    title: "",
    vendor: null,
    vendor_address: null,
    purchase_order: null,
    job_card: null,
    payment_term: null,
    department: null,
    tax: null,
    bill_number: "",
    bill_date: getTodayDate(),
    bill_due_date: "",
    status: "draft",
    discount: "no",
    discount_amount: undefined,
    notes: "",
    part_items: [],
    service_items: [],
    expense_items: [],
}

const STATUS_OPTIONS = BillStatus.map((value) => ({
    value,
    label: value.replace(/_/g, " ").replace(/\b\w/g, (c) => c.toUpperCase()),
}))

const DISCOUNT_OPTIONS = DiscountType.map((value) => ({
    value,
    label: value.replace(/_/g, " ").replace(/\b\w/g, (c) => c.toUpperCase()),
}))

const mapLookupOption = (item: any) => ({
    value: String(item.id),
    label: item.name ?? item.title ?? `#${item.id}`,
})

const STORE_OBJECT = { getOptionValue: (o: any) => o, getOptionLabel: (o: any) => o.label }

function mapToFormValues(data: unknown): BillFormValues {
    const d = (data as any)?.data ?? data ?? {}

    return {
        title: d.title || "",
        vendor: toRelation(d.vendor_id, d.vendor?.name ?? d.vendor_name),
        vendor_address: toRelation(d.vendor_address_id, d.vendor_address?.address),
        purchase_order: toRelation(d.purchase_order_id, d.purchase_order?.order_number ?? d.purchase_order_number),
        job_card: toRelation(d.job_card_id, d.job_card?.order_number ?? d.job_card_number),
        payment_term: toRelation(d.payment_terms_id, d.payment_terms?.name ?? d.payment_terms_name),
        department: toRelation(d.department_id, d.department?.name ?? d.department_name),
        tax: toRelation(d.tax_id, d.tax?.name ? `${d.tax.name} (${d.tax.rate}%)` : d.tax_title),
        bill_number: d.bill_number || "",
        bill_date: d.bill_date ? d.bill_date.split("T")[0] : "",
        bill_due_date: d.bill_due_date ? d.bill_due_date.split("T")[0] : "",
        status: d.status || "draft",
        discount: d.discount_type || "no",
        discount_amount: d.discount_amount != null ? Number(d.discount_amount) : undefined,
        notes: d.notes || "",
        part_items: (d.parts ?? []).map((p: any) => ({
            part_id: p.part_id ?? p.id,
            title: p.part?.name ?? p.part_name ?? p.title ?? "",
            quantity: Number(p.quantity) || 1,
            rate: Number(p.rate) || 0,
            discount_amount: p.discount_amount != null ? Number(p.discount_amount) : undefined,
            description: p.description ?? "",
        })),
        service_items: (d.services ?? []).map((s: any) => ({
            service_id: s.service_id ?? s.id,
            title: s.service?.name ?? s.service_name ?? s.title ?? "",
            quantity: Number(s.quantity) || 1,
            rate: Number(s.rate) || 0,
            discount_amount: s.discount_amount != null ? Number(s.discount_amount) : undefined,
            description: s.description ?? "",
        })),
        expense_items: (d.expenses ?? []).map((e: any) => ({
            expense_id: e.expense_id ?? e.id,
            title: e.expense?.title ?? e.expense_title ?? e.title ?? "",
            quantity: Number(e.quantity) || 1,
            rate: Number(e.rate) || 0,
            discount_amount: e.discount_amount != null ? Number(e.discount_amount) : undefined,
            description: e.description ?? "",
        })),
    }
}

function mapFormToPayload(values: BillFormValues) {
    return {
        title: values.title,
        vendor_id: toId(values.vendor),
        vendor_address_id: toId(values.vendor_address),
        purchase_order_id: toId(values.purchase_order),
        job_card_id: toId(values.job_card),
        payment_terms_id: toId(values.payment_term),
        department_id: toId(values.department),
        tax_id: toId(values.tax) ? Number(toId(values.tax)) : undefined,
        bill_number: values.bill_number || undefined,
        bill_date: values.bill_date || undefined,
        bill_due_date: values.bill_due_date || undefined,
        status: values.status || undefined,
        discount_type: values.discount || undefined,
        discount_amount: values.discount === "transaction_level" ? (values.discount_amount ?? 0) : undefined,
        notes: values.notes || undefined,
        part_items: (values.part_items ?? []).map((item) => ({
            part_id: item.part_id,
            quantity: item.quantity,
            rate: item.rate,
            discount_amount: values.discount === "line_item_level" ? (item.discount_amount ?? 0) : undefined,
            description: item.description || undefined,
        })),
        service_items: (values.service_items ?? []).map((item) => ({
            service_id: item.service_id,
            quantity: item.quantity,
            rate: item.rate,
            discount_amount: values.discount === "line_item_level" ? (item.discount_amount ?? 0) : undefined,
            description: item.description || undefined,
        })),
        expense_items: (values.expense_items ?? []).map((item) => ({
            expense_id: item.expense_id,
            quantity: item.quantity,
            rate: item.rate,
            discount_amount: values.discount === "line_item_level" ? (item.discount_amount ?? 0) : undefined,
            description: item.description || undefined,
        })),
    }
}

// ── Transaction-level discount field (conditional) ──

function TransactionDiscountField() {
    const { watch } = useFormContext<BillFormValues>()
    const discount = watch("discount")
    if (discount !== "transaction_level") return null
    return (
        <RhfTextField
            name="discount_amount"
            label="Discount Amount"
            type="number"
            placeholder="0.00"
        />
    )
}

// ── Component ──

export function BillForm({ resourceId, initialData, onSuccess }: BillFormProps) {
    const api = useAuthApi()

    const { form, isEditing } = useResourceForm<BillFormValues, any>({
        schema: billFormSchema,
        defaultValues: DEFAULT_VALUES,
        resourceId,
        initialData,
        queryKey: [BILL_ROUTES.BY_ID, resourceId],
        mapToFormValues,
    })

    const discount = form.watch("discount")
    const isLineItemDiscount = discount === "line_item_level"

    const { mutate, error, isPending } = useFormMutation(form, {
        mutationFn: (values: BillFormValues) => {
            const payload = mapFormToPayload(values)
            const promise = (isEditing && resourceId
                ? api.bills.update(resourceId, payload)
                : api.bills.create(payload)) as Promise<any>
            toast.promise(promise, {
                loading: isEditing ? "Updating bill..." : "Creating bill...",
                success: isEditing ? "Bill updated successfully" : "Bill created successfully",
                error: isEditing ? "Failed to update bill" : "Failed to create bill",
            })
            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 bill" : "Failed to create bill"}
                    </AlertTitle>
                    {error.message}
                </Alert>
            )}

            <div className="grid grid-cols-1 gap-6 lg:grid-cols-12">

                {/* ── Main column (9/12) ── */}
                <div className="lg:col-span-9">
                    <FieldGroup>
                        <RhfTextField name="title" label="Title" placeholder="Enter bill title" required />

                        <div className="grid grid-cols-1 gap-4 sm:grid-cols-2">
                            <RhfAutoGenerateField autoFetch table="bills" name="bill_number" label="Bill Number" placeholder="e.g. BILL-001" />
                            <RhfSelectField name="status" label="Status" options={STATUS_OPTIONS} />
                        </div>

                        <div className="grid grid-cols-1 gap-4 sm:grid-cols-2">
                            <RhfSelectField name="discount" label="Discount Type" options={DISCOUNT_OPTIONS} />
                        </div>

                        <TransactionDiscountField />

                        <PartsSelectorField<BillFormValues, "part_items"> name="part_items" showDiscount={isLineItemDiscount} />
                        <ServicesSelectorField<BillFormValues, "service_items"> name="service_items" showDiscount={isLineItemDiscount} />
                        <ExpenseItemsSelectorField<BillFormValues, "expense_items"> name="expense_items" showDiscount={isLineItemDiscount} />

                        <RhfTextareaField name="notes" label="Notes" placeholder="Additional notes" rows={3} />

                        <Button type="submit" variant="default" disabled={isPending}>
                            {isEditing ? <Save /> : <Plus />}
                            {isPending
                                ? (isEditing ? "Updating..." : "Creating...")
                                : (isEditing ? "Update Bill" : "Create Bill")}
                        </Button>
                    </FieldGroup>
                </div>

                {/* ── Sidebar column (3/12) ── */}
                <div className="lg:col-span-3">
                    <Card>
                        <CardHeader className="pb-3">
                            <CardTitle className="text-sm font-medium text-muted-foreground uppercase tracking-wide">Details</CardTitle>
                        </CardHeader>
                        <CardContent>
                            <FieldGroup>
                                <div className="grid grid-cols-1 gap-4 sm:grid-cols-2 lg:grid-cols-1">
                                    <RhfDateField name="bill_date" label="Bill Date" />
                                    <RhfDateField name="bill_due_date" label="Due Date" />
                                </div>

                                <RhfAsyncSelectField
                                    name="vendor"
                                    label="Vendor"
                                    placeholder="Select vendor"
                                    queryKey={[VENDOR_ROUTES.INDEX]}
                                    listFn={() => api.vendors.list()}
                                    mapOption={mapLookupOption}
                                    {...STORE_OBJECT}
                                />

                                <RhfAsyncSelectField
                                    name="tax"
                                    label="Tax"
                                    placeholder="Select tax rate"
                                    queryKey={[TAX_ROUTES.INDEX]}
                                    listFn={() => api.taxes.list()}
                                    mapOption={(item: any) => ({
                                        value: String(item.id),
                                        label: item.title ? `${item.title} (${item.rate}%)` : `#${item.id}`,
                                    })}
                                    {...STORE_OBJECT}
                                />

                                <RhfAsyncSelectField
                                    name="department"
                                    label="Department"
                                    placeholder="Select department"
                                    queryKey={[DEPARTMENT_ROUTES.INDEX]}
                                    listFn={() => api.departments.list()}
                                    mapOption={mapLookupOption}
                                    {...STORE_OBJECT}
                                />

                                <RhfAsyncSelectField
                                    name="payment_term"
                                    label="Payment Terms"
                                    placeholder="Select payment terms"
                                    queryKey={[PAYMENT_TERM_ROUTES.INDEX]}
                                    listFn={() => api.paymentTerms.list()}
                                    mapOption={mapLookupOption}
                                    {...STORE_OBJECT}
                                />

                                <RhfAsyncSelectField
                                    name="job_card"
                                    label="Job Card"
                                    placeholder="Select job card"
                                    queryKey={[JOB_CARD_ROUTES.INDEX]}
                                    listFn={() => api.jobCards.list()}
                                    mapOption={(item: any) => ({
                                        value: String(item.id),
                                        label: item.order_number || item.estimate_number || `#${item.id}`,
                                    })}
                                    {...STORE_OBJECT}
                                />

                                <RhfAsyncSelectField
                                    name="purchase_order"
                                    label="Purchase Order"
                                    placeholder="Select purchase order"
                                    queryKey={[PURCHASE_ORDER_ROUTES.INDEX]}
                                    listFn={() => api.purchaseOrders.list()}
                                    mapOption={(item: any) => ({
                                        value: String(item.id),
                                        label: item.order_number || item.title || `#${item.id}`,
                                    })}
                                    {...STORE_OBJECT}
                                />
                            </FieldGroup>
                        </CardContent>
                    </Card>

                    <div className="mt-4">
                        <BillFormSummary />
                    </div>
                </div>

            </div>
        </Rhform>
    )
}