import { useEffect, useRef, useState } from "react";
import { Button, InlineLoading, Modal, RadioButton, RadioButtonGroup, Tag } from "@carbon/react";
import { api } from "../lib/api";
import type { ErpnextPushResult } from "../lib/erpnext";
import { describePush, failedPush, summarizeBatch } from "../lib/erpnextUi";
import { useReturnFocus } from "../hooks/useReturnFocus";

export interface SendTarget {
  id: number;
  number: string;
}

interface Props {
  open: boolean;
  invoices: SendTarget[];
  /** Cancelled or draft invoices that were left out of the selection. */
  skipped?: number;
  /** The "submit on push" setting; the user still chooses explicitly. */
  defaultSubmit: boolean;
  onClose: () => void;
  /** Called once when a send has finished, so the list can refresh its statuses. */
  onFinished: (results: ErpnextPushResult[]) => void;
}

type Phase = "confirm" | "running" | "done";

const TAG = { success: "green", info: "blue", warning: "warm-gray", error: "red" } as const;

/** Confirm step (draft or submit), then a sequential send with progress, then per-invoice results. A failure never stops the rest. */
export default function SendToErpnextModal({ open, invoices, skipped = 0, defaultSubmit, onClose, onFinished }: Props) {
  const [submit, setSubmit] = useState(defaultSubmit);
  const [phase, setPhase] = useState<Phase>("confirm");
  const [results, setResults] = useState<ErpnextPushResult[]>([]);
  const alive = useRef(true);
  useReturnFocus(open);

  useEffect(() => {
    alive.current = true;
    return () => {
      alive.current = false;
    };
  }, []);

  useEffect(() => {
    if (!open) return;
    setSubmit(defaultSubmit);
    setPhase("confirm");
    setResults([]);
  }, [open, defaultSubmit]);

  const run = async () => {
    setPhase("running");
    const out: ErpnextPushResult[] = [];
    for (const inv of invoices) {
      let result: ErpnextPushResult;
      try {
        result = await api.erpnextPushInvoice(inv.id, submit);
      } catch (e) {
        // Not set up, or the command itself failed: this row fails, the others still go.
        result = failedPush(inv.id, inv.number, e);
      }
      out.push(result);
      if (alive.current) setResults([...out]);
    }
    if (alive.current) setPhase("done");
    onFinished(out);
  };

  const count = invoices.length;
  const noun = count === 1 ? "invoice" : "invoices";

  if (phase === "confirm") {
    return (
      <Modal
        open={open}
        modalHeading={count === 1 ? `Send ${invoices[0]?.number} to ERPNext` : `Send ${count} invoices to ERPNext`}
        primaryButtonText={`Send ${count} ${noun}`}
        secondaryButtonText="Cancel"
        primaryButtonDisabled={count === 0}
        onRequestClose={onClose}
        onRequestSubmit={() => void run()}
      >
        <div className="voiced-stack">
          <RadioButtonGroup legendText="What should ERPNext do with it?" name="erp-send-mode" orientation="vertical" valueSelected={submit ? "submit" : "draft"} onChange={(v) => setSubmit(v === "submit")}>
            <RadioButton id="erp-send-draft" value="draft" labelText="Save as a draft for review" />
            <RadioButton id="erp-send-submit" value="submit" labelText="Submit it (posts to the books)" />
          </RadioButtonGroup>
          <p className="voiced-muted">
            An invoice that is already in ERPNext is never overwritten or created twice.
            {skipped > 0 ? ` ${skipped} cancelled ${skipped === 1 ? "invoice is" : "invoices are"} left out: cancelled invoices are never sent.` : ""}
          </p>
        </div>
      </Modal>
    );
  }

  const summary = phase === "done" ? summarizeBatch(results) : null;
  return (
    <Modal
      open={open}
      passiveModal
      modalHeading={phase === "running" ? "Sending to ERPNext" : "Send finished"}
      preventCloseOnClickOutside
      onRequestClose={() => {
        if (phase === "done") onClose();
      }}
    >
      <div className="voiced-stack">
        {phase === "running" ? (
          <InlineLoading description={`Sent ${results.length} of ${count}…`} />
        ) : (
          <p role="status">
            <strong>{summary?.title}</strong>
          </p>
        )}
        <ul className="voiced-erp__results" aria-label="Results">
          {results.map((r) => {
            const note = describePush(r);
            return (
              <li key={r.invoiceId}>
                <Tag type={TAG[note.kind]} size="sm">
                  {r.ok ? (r.noOp ? "Up to date" : r.remoteDocstatus === 1 ? "Submitted" : "Draft") : r.status === "conflict" ? "Conflict" : r.status === "refused" ? "Not sent" : "Error"}
                </Tag>{" "}
                <strong>{r.number || `#${r.invoiceId}`}</strong>
                {r.remoteName && r.ok ? <span className="voiced-muted"> {r.remoteName}</span> : null}
                {!r.ok && r.error ? <div className="voiced-muted">{r.error}</div> : null}
                {r.ok && r.warnings.length > 0 ? <div className="voiced-muted">{r.warnings.join(" ")}</div> : null}
              </li>
            );
          })}
        </ul>
        {phase === "done" ? (
          <Button kind="primary" size="md" onClick={onClose}>
            Close
          </Button>
        ) : null}
      </div>
    </Modal>
  );
}