import { useState } from "react";
import { data, type ActionFunctionArgs, type LoaderFunctionArgs } from "@remix-run/node";
import { Form, useLoaderData, useNavigation } from "@remix-run/react";
import {
  Page,
  Layout,
  Card,
  BlockStack,
  InlineStack,
  Text,
  Button,
  ButtonGroup,
  ResourceList,
  ResourceItem,
  Badge,
  EmptyState,
  Select,
} from "@shopify/polaris";
import { TitleBar } from "@shopify/app-bridge-react";
import { authenticate } from "../shopify.server";
import db from "../db.server";
import { listVerticalTemplates, seedVerticalTemplate, type VerticalKey } from "../services/templates.server";
import { canAddLocation, getShopTier, locationLimitFor } from "../services/billing.server";

export const loader = async ({ request }: LoaderFunctionArgs) => {
  const { session } = await authenticate.admin(request);

  const locations = await db.location.findMany({
    where: { shopDomain: session.shop },
    include: { _count: { select: { slotTemplates: true, blackouts: true } } },
    orderBy: { createdAt: "asc" },
  });

  return { locations, verticals: listVerticalTemplates() };
};

export const action = async ({ request }: ActionFunctionArgs) => {
  const { session } = await authenticate.admin(request);
  const formData = await request.formData();
  const intent = formData.get("intent");

  if (intent === "seed-template") {
    if (!(await canAddLocation(session.shop))) {
      const tier = await getShopTier(session.shop);
      return data(
        { error: `Your ${tier} plan allows up to ${locationLimitFor(tier)} location(s). Upgrade to add more.` },
        { status: 403 },
      );
    }
    const vertical = formData.get("vertical") as VerticalKey;
    await seedVerticalTemplate(session.shop, vertical);
    return data({ ok: true });
  }

  if (intent === "delete-location") {
    const id = formData.get("id") as string;
    await db.location.deleteMany({ where: { id, shopDomain: session.shop } });
    return data({ ok: true });
  }

  return data({ ok: false }, { status: 400 });
};

export default function LocationsIndex() {
  const { locations, verticals } = useLoaderData<typeof loader>();
  const navigation = useNavigation();
  const isSubmitting = navigation.state === "submitting";
  const [vertical, setVertical] = useState<string>(verticals[0]);

  return (
    <Page>
      <TitleBar title="Locations" />
      <BlockStack gap="500">
        <Layout>
          <Layout.Section>
            {locations.length === 0 ? (
              <Card>
                <EmptyState
                  heading="Set up your first location"
                  image="https://cdn.shopify.com/s/files/1/0757/9955/files/empty-state.svg"
                >
                  <BlockStack gap="400">
                    <Text as="p" variant="bodyMd">
                      Start from a vertical template — it seeds a location with a
                      realistic weekly Pickup/Delivery schedule you can then edit,
                      or add a location from scratch.
                    </Text>
                    <InlineStack gap="300" blockAlign="center">
                      <div style={{ minWidth: 180 }}>
                        <Select
                          label="Vertical"
                          labelHidden
                          options={verticals.map((v) => ({ label: capitalize(v), value: v }))}
                          value={vertical}
                          onChange={setVertical}
                        />
                      </div>
                      <Form method="post">
                        <input type="hidden" name="intent" value="seed-template" />
                        <input type="hidden" name="vertical" value={vertical} />
                        <Button submit variant="primary" loading={isSubmitting}>
                          Seed {capitalize(vertical)} template
                        </Button>
                      </Form>
                      <Button url="/app/locations/new">Add location manually</Button>
                    </InlineStack>
                  </BlockStack>
                </EmptyState>
              </Card>
            ) : (
              <Card padding="0">
                <ResourceList
                  items={locations}
                  resourceName={{ singular: "location", plural: "locations" }}
                  renderItem={(location) => (
                    <ResourceItem
                      id={location.id}
                      url={`/app/locations/${location.id}`}
                      accessibilityLabel={`View ${location.name}`}
                    >
                      <InlineStack align="space-between" blockAlign="center">
                        <BlockStack gap="100">
                          <Text as="h3" variant="bodyMd" fontWeight="bold">
                            {location.name}
                          </Text>
                          <Text as="span" variant="bodySm" tone="subdued">
                            {location.address || "No address set"} · {location.timezone}
                          </Text>
                        </BlockStack>
                        <InlineStack gap="200" blockAlign="center">
                          <Badge>{`${location._count.slotTemplates} slot templates`}</Badge>
                          <Badge tone={location.active ? "success" : "critical"}>
                            {location.active ? "Active" : "Inactive"}
                          </Badge>
                        </InlineStack>
                      </InlineStack>
                    </ResourceItem>
                  )}
                />
              </Card>
            )}
          </Layout.Section>
          {locations.length > 0 && (
            <Layout.Section>
              <ButtonGroup>
                <Button url="/app/locations/new" variant="primary">
                  Add location
                </Button>
              </ButtonGroup>
            </Layout.Section>
          )}
        </Layout>
      </BlockStack>
    </Page>
  );
}

function capitalize(s: string) {
  return s.charAt(0).toUpperCase() + s.slice(1);
}