"use client";

import { useState, type FormEvent } from "react";
import { useApiList } from "@/hooks/use-api-list";
import { Button } from "@/components/ui/button";
import { Input } from "@/components/ui/input";
import { Label } from "@/components/ui/label";
import { Textarea } from "@/components/ui/textarea";
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from "@/components/ui/select";
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from "@/components/ui/table";

// Shape returned by GET /api/maintenance-records — snake_case per this
// repo's API-boundary convention (see src/lib/maintenance-records.ts's
// toRecord()). An "open" record is one where end_date is null.
interface MaintenanceRecordRecord {
  id: string;
  asset_item_id: string;
  type: "repair" | "warranty" | "preventive";
  vendor_id: string | null;
  issue_description: string;
  resolution_notes: string | null;
  start_date: string;
  end_date: string | null;
  created_at: string;
}

// Shape returned by GET /api/assets — only the field used to populate the
// assetItemId <Select> here (see src/app/assets/page.tsx's AssetItemRecord
// for the full shape).
interface AssetItemRecord {
  id: string;
  serial_number: string;
}

// Shape returned by GET /api/vendors — only the field used to populate the
// vendorId <Select> here (see src/app/vendors/page.tsx's VendorRecord for
// the full shape).
interface VendorRecord {
  id: string;
  name: string;
}

// The 4 AssetItemStatus enum values, reused verbatim as the targetStatus
// <Select>'s option list — mirrors src/lib/maintenance-records.ts's own
// assetItemStatusValues constant (not re-derived from an API call, this is
// a closed set already known client-side, same precedent as licenses
// page's licenseType/perpetual|subscription <Select>).
const ASSET_ITEM_STATUS_VALUES = ["in_stock", "assigned", "repair", "retired"] as const;

// Radix <Select.Item> can't take an empty-string value, so "no vendor" is
// represented by this sentinel in the form state and translated to "omit
// the key" on submit — same pattern as licenses page's
// NO_PURCHASE_ORDER_VALUE / employees page's NO_MANAGER_VALUE.
const NO_VENDOR_VALUE = "none";

function todayDateString(): string {
  return new Date().toISOString().slice(0, 10);
}

export default function MaintenanceRecordsPage() {
  const {
    data: maintenanceRecords,
    loading,
    error,
    refetch,
  } = useApiList<MaintenanceRecordRecord>("/api/maintenance-records");

  const { data: assetItems } = useApiList<AssetItemRecord>("/api/assets");
  const { data: vendors } = useApiList<VendorRecord>("/api/vendors");

  const [assetItemId, setAssetItemId] = useState("");
  const [type, setType] = useState("");
  const [vendorId, setVendorId] = useState(NO_VENDOR_VALUE);
  const [issueDescription, setIssueDescription] = useState("");
  const [startDate, setStartDate] = useState("");
  const [submitting, setSubmitting] = useState(false);
  const [submitError, setSubmitError] = useState<string | null>(null);

  // Per-row close mini-form state, keyed by maintenance record id — kept as
  // separate maps (rather than one nested-object map) to keep each field's
  // setter a plain string setter, same shape as returnErrors/returningId on
  // assignments/page.tsx which this page mirrors.
  const [closeEndDate, setCloseEndDate] = useState<Record<string, string>>({});
  const [closeResolutionNotes, setCloseResolutionNotes] = useState<Record<string, string>>({});
  const [closeTargetStatus, setCloseTargetStatus] = useState<Record<string, string>>({});
  const [closeErrors, setCloseErrors] = useState<Record<string, string>>({});
  const [closingId, setClosingId] = useState<string | null>(null);

  async function handleSubmit(event: FormEvent<HTMLFormElement>) {
    event.preventDefault();
    setSubmitError(null);
    setSubmitting(true);

    try {
      const response = await fetch("/api/maintenance-records", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({
          assetItemId,
          type,
          issueDescription,
          startDate,
          // Omit the key entirely when left unselected, rather than sending
          // null — matches licenses page's purchaseOrderId pattern.
          ...(vendorId !== NO_VENDOR_VALUE ? { vendorId } : {}),
        }),
      });

      let body: unknown;
      try {
        body = await response.json();
      } catch {
        body = null;
      }

      if (!response.ok) {
        const message =
          body !== null &&
          typeof body === "object" &&
          "error" in body &&
          typeof (body as { error: unknown }).error === "string"
            ? (body as { error: string }).error
            : "Request failed";
        setSubmitError(message);
        return;
      }

      setAssetItemId("");
      setType("");
      setVendorId(NO_VENDOR_VALUE);
      setIssueDescription("");
      setStartDate("");
      refetch();
    } catch {
      setSubmitError("Request failed");
    } finally {
      setSubmitting(false);
    }
  }

  async function handleClose(id: string) {
    setClosingId(id);
    setCloseErrors((previous) => {
      const next = { ...previous };
      delete next[id];
      return next;
    });

    const endDate = closeEndDate[id] ?? todayDateString();
    const resolutionNotes = closeResolutionNotes[id] ?? "";
    const targetStatus = closeTargetStatus[id] ?? "";

    try {
      // PATCH /api/maintenance-records/[id]'s body is
      // `{endDate, resolutionNotes?, targetStatus}` — see src/lib/
      // maintenance-records.ts's validateCloseMaintenanceRecordInput().
      // Unlike Assignment's returnedAt, targetStatus is REQUIRED and never
      // defaulted server-side, so it's always sent here (an empty string
      // if unselected, which the server rejects with a clean 400 message
      // surfaced below, same as any other validation failure).
      const response = await fetch(`/api/maintenance-records/${id}`, {
        method: "PATCH",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({
          endDate,
          targetStatus,
          ...(resolutionNotes.trim() !== "" ? { resolutionNotes } : {}),
        }),
      });

      let body: unknown;
      try {
        body = await response.json();
      } catch {
        body = null;
      }

      if (!response.ok) {
        const message =
          body !== null &&
          typeof body === "object" &&
          "error" in body &&
          typeof (body as { error: unknown }).error === "string"
            ? (body as { error: string }).error
            : "Request failed";
        setCloseErrors((previous) => ({ ...previous, [id]: message }));
        return;
      }

      setCloseEndDate((previous) => {
        const next = { ...previous };
        delete next[id];
        return next;
      });
      setCloseResolutionNotes((previous) => {
        const next = { ...previous };
        delete next[id];
        return next;
      });
      setCloseTargetStatus((previous) => {
        const next = { ...previous };
        delete next[id];
        return next;
      });
      refetch();
    } catch {
      setCloseErrors((previous) => ({ ...previous, [id]: "Request failed" }));
    } finally {
      setClosingId(null);
    }
  }

  return (
    <div className="flex flex-col gap-8 p-6">
      <h1 className="text-xl font-semibold">Maintenance Records</h1>

      <section className="flex flex-col gap-3">
        {loading ? (
          <p className="text-sm text-muted-foreground">Loading...</p>
        ) : error ? (
          <p className="text-sm text-destructive">{error}</p>
        ) : (
          <Table>
            <TableHeader>
              <TableRow>
                <TableHead>ID</TableHead>
                <TableHead>Asset Item ID</TableHead>
                <TableHead>Type</TableHead>
                <TableHead>Vendor ID</TableHead>
                <TableHead>Issue Description</TableHead>
                <TableHead>Resolution Notes</TableHead>
                <TableHead>Start Date</TableHead>
                <TableHead>End Date</TableHead>
                <TableHead>Created At</TableHead>
                <TableHead>Actions</TableHead>
              </TableRow>
            </TableHeader>
            <TableBody>
              {maintenanceRecords.map((record) => (
                <TableRow key={record.id}>
                  <TableCell>{record.id}</TableCell>
                  <TableCell>{record.asset_item_id}</TableCell>
                  <TableCell>{record.type}</TableCell>
                  <TableCell>{record.vendor_id ?? "-"}</TableCell>
                  <TableCell>{record.issue_description}</TableCell>
                  <TableCell>{record.resolution_notes ?? "-"}</TableCell>
                  <TableCell>{record.start_date}</TableCell>
                  <TableCell>{record.end_date ?? "-"}</TableCell>
                  <TableCell>{record.created_at}</TableCell>
                  <TableCell>
                    {record.end_date === null ? (
                      <div className="flex w-56 flex-col gap-1">
                        <Input
                          type="date"
                          aria-label="End date"
                          value={closeEndDate[record.id] ?? todayDateString()}
                          onChange={(event) =>
                            setCloseEndDate((previous) => ({
                              ...previous,
                              [record.id]: event.target.value,
                            }))
                          }
                        />
                        <Input
                          type="text"
                          placeholder="Resolution notes (optional)"
                          value={closeResolutionNotes[record.id] ?? ""}
                          onChange={(event) =>
                            setCloseResolutionNotes((previous) => ({
                              ...previous,
                              [record.id]: event.target.value,
                            }))
                          }
                        />
                        <Select
                          value={closeTargetStatus[record.id] ?? ""}
                          onValueChange={(value) =>
                            setCloseTargetStatus((previous) => ({
                              ...previous,
                              [record.id]: value,
                            }))
                          }
                        >
                          <SelectTrigger className="w-full">
                            <SelectValue placeholder="Target status" />
                          </SelectTrigger>
                          <SelectContent>
                            {ASSET_ITEM_STATUS_VALUES.map((status) => (
                              <SelectItem key={status} value={status}>
                                {status}
                              </SelectItem>
                            ))}
                          </SelectContent>
                        </Select>
                        <Button
                          type="button"
                          size="sm"
                          variant="outline"
                          disabled={closingId === record.id}
                          onClick={() => handleClose(record.id)}
                        >
                          {closingId === record.id ? "Closing..." : "Close"}
                        </Button>
                        {closeErrors[record.id] ? (
                          <p className="text-xs text-destructive">
                            {closeErrors[record.id]}
                          </p>
                        ) : null}
                      </div>
                    ) : (
                      "-"
                    )}
                  </TableCell>
                </TableRow>
              ))}
            </TableBody>
          </Table>
        )}
      </section>

      <section className="flex max-w-sm flex-col gap-4">
        <h2 className="text-lg font-semibold">New Maintenance Record</h2>

        <form className="flex flex-col gap-4" onSubmit={handleSubmit}>
          <div className="flex flex-col gap-2">
            <Label htmlFor="assetItemId">Asset Item</Label>
            <Select value={assetItemId} onValueChange={setAssetItemId} required>
              <SelectTrigger id="assetItemId" className="w-full">
                <SelectValue placeholder="Select an asset item" />
              </SelectTrigger>
              <SelectContent>
                {assetItems.map((assetItem) => (
                  <SelectItem key={assetItem.id} value={assetItem.id}>
                    {assetItem.serial_number}
                  </SelectItem>
                ))}
              </SelectContent>
            </Select>
          </div>

          <div className="flex flex-col gap-2">
            <Label htmlFor="type">Type</Label>
            <Select value={type} onValueChange={setType} required>
              <SelectTrigger id="type" className="w-full">
                <SelectValue placeholder="Select a type" />
              </SelectTrigger>
              <SelectContent>
                <SelectItem value="repair">repair</SelectItem>
                <SelectItem value="warranty">warranty</SelectItem>
                <SelectItem value="preventive">preventive</SelectItem>
              </SelectContent>
            </Select>
          </div>

          <div className="flex flex-col gap-2">
            <Label htmlFor="vendorId">Vendor (optional)</Label>
            <Select value={vendorId} onValueChange={setVendorId}>
              <SelectTrigger id="vendorId" className="w-full">
                <SelectValue />
              </SelectTrigger>
              <SelectContent>
                <SelectItem value={NO_VENDOR_VALUE}>None</SelectItem>
                {vendors.map((vendor) => (
                  <SelectItem key={vendor.id} value={vendor.id}>
                    {vendor.name}
                  </SelectItem>
                ))}
              </SelectContent>
            </Select>
          </div>

          <div className="flex flex-col gap-2">
            <Label htmlFor="issueDescription">Issue Description</Label>
            <Textarea
              id="issueDescription"
              value={issueDescription}
              onChange={(event) => setIssueDescription(event.target.value)}
              required
            />
          </div>

          <div className="flex flex-col gap-2">
            <Label htmlFor="startDate">Start Date</Label>
            <Input
              id="startDate"
              type="date"
              value={startDate}
              onChange={(event) => setStartDate(event.target.value)}
              required
            />
          </div>

          {submitError ? <p className="text-sm text-destructive">{submitError}</p> : null}

          <Button type="submit" disabled={submitting}>
            {submitting ? "Creating..." : "Create Maintenance Record"}
          </Button>
        </form>
      </section>
    </div>
  );
}