import React from "react";
import { Box, Alert, AlertTitle } from "@mui/material";
import {
  BobStateName,
  GetSwapInfoResponseExt,
  GetSwapInfoResponseExtRunningSwap,
  isGetSwapInfoResponseRunningSwap,
  TimelockCancel,
  TimelockNone,
} from "models/tauriModelExt";
import { ReactNode } from "react";
import { exhaustiveGuard } from "utils/typescriptUtils";
import HumanizedBitcoinBlockDuration from "../../other/HumanizedBitcoinBlockDuration";
import TruncatedText from "../../other/TruncatedText";
import { SwapMoneroRecoveryButton } from "../../pages/history/table/SwapMoneroRecoveryButton";
import { TimelockTimeline } from "./TimelockTimeline";
import { useIsSpecificSwapRunning, useAppSelector } from "store/hooks";
import { selectSwapTimelock } from "store/selectors";
import { ExpiredTimelocks } from "models/tauriModel";

/**
 * Component for displaying a list of messages.
 * @param messages - Array of messages to display.
 * @returns JSX.Element
 */
function MessageList({ messages }: { messages: ReactNode[] }) {
  return (
    <Box
      component="ul"
      sx={{
        padding: "0px",
        margin: "0px",
        "& li": {
          marginBottom: 0.5,
          "&:last-child": {
            marginBottom: 0,
          },
        },
      }}
    >
      {messages
        .filter((msg) => msg != null)
        .map((msg, i) => (
          <li key={i}>{msg}</li>
        ))}
    </Box>
  );
}

/**
 * Sub-component for displaying alerts when the swap is in a safe state.
 * @param swap - The swap information.
 * @returns JSX.Element
 */
function BitcoinRedeemedStateAlert({ swap }: { swap: GetSwapInfoResponseExt }) {
  return (
    <Box
      sx={{
        display: "flex",
        flexDirection: "column",
        gap: 1,
      }}
    >
      <MessageList
        messages={[
          "The Bitcoin has been redeemed by the other party",
          "There is no risk of losing funds. Take as much time as you need",
          "The Monero will automatically be redeemed to your provided address once you resume the swap",
          "If this step fails, you can manually redeem your funds",
        ]}
      />
      <SwapMoneroRecoveryButton
        swap={swap}
        size="small"
        variant="contained"
      />
    </Box>
  );
}

/**
 * Sub-component for displaying alerts when the swap is in a state with no timelock info.
 * @param swap - The swap information.
 * @param punishTimelockOffset - The punish timelock offset.
 * @returns JSX.Element
 */
function BitcoinLockedNoTimelockExpiredStateAlert({
  timelock,
  cancelTimelockOffset,
  punishTimelockOffset,
  isRunning,
}: {
  timelock: TimelockNone;
  cancelTimelockOffset: number;
  punishTimelockOffset: number;
  isRunning: boolean;
}) {
  return (
    <MessageList
      messages={[
        <>
          If the swap isn't completed in{" "}
          <HumanizedBitcoinBlockDuration
            blocks={timelock.content.blocks_left}
            displayBlocks={false}
          />
          , it will be refunded
        </>,
        "For that, you need to have the app open sometime within the refund period",
        <>
          After that, cooperation from the other party would be required to
          recover the funds
        </>,
        isRunning ? null : "Please resume the swap to continue",
      ]}
    />
  );
}

/**
 * Sub-component for displaying alerts when the swap timelock is expired
 * The swap could be cancelled but not necessarily (the transaction might not have been published yet)
 * But it doesn't matter because the swap cannot be completed anymore
 * @param swap - The swap information.
 * @returns JSX.Element
 */
function BitcoinPossiblyCancelledAlert({
  swap,
  timelock,
}: {
  swap: GetSwapInfoResponseExt;
  timelock: TimelockCancel;
}) {
  return (
    <MessageList
      messages={[
        "The swap is being cancelled because it was not completed in time",
        "To refund your Bitcoin, resume the swap",
        <>
          If we haven't refunded in{" "}
          <HumanizedBitcoinBlockDuration
            blocks={timelock.content.blocks_left}
          />
          , cooperation from the other party will be required to recover the
          funds
        </>,
      ]}
    />
  );
}

/**
 * Sub-component for displaying alerts requiring immediate action.
 * @returns JSX.Element
 */
function PunishTimelockExpiredAlert() {
  return (
    <MessageList
      messages={[
        "We couldn't refund within the refund period",
        "We might still be able to redeem the Monero. However, this will require cooperation from the other party",
        "Resume the swap as soon as possible",
      ]}
    />
  );
}

/**
 * Main component for displaying the appropriate swap alert status text.
 * @param swap - The swap information.
 * @returns JSX.Element | null
 */
export function StateAlert({
  swap,
  timelock,
  isRunning,
}: {
  swap: GetSwapInfoResponseExtRunningSwap;
  timelock: ExpiredTimelocks | null;
  isRunning: boolean;
}) {
  switch (swap.state_name) {
    // This is the state where the swap is safe because the other party has redeemed the Bitcoin
    // It cannot be punished anymore
    case BobStateName.BtcRedeemed:
      return <BitcoinRedeemedStateAlert swap={swap} />;

    // These are states that are at risk of punishment because the Bitcoin have been locked
    // but has not been redeemed yet by the other party
    case BobStateName.BtcLocked:
    case BobStateName.XmrLockProofReceived:
    case BobStateName.XmrLocked:
    case BobStateName.EncSigSent:
    case BobStateName.CancelTimelockExpired:
    case BobStateName.BtcCancelled:
    case BobStateName.BtcRefundPublished: // Even if the transactions have been published, it cannot be
    case BobStateName.BtcEarlyRefundPublished: // guaranteed that they will be confirmed in time
      if (timelock != null) {
        switch (timelock.type) {
          case "None":
            return (
              <BitcoinLockedNoTimelockExpiredStateAlert
                timelock={timelock}
                cancelTimelockOffset={swap.cancel_timelock}
                punishTimelockOffset={swap.punish_timelock}
                isRunning={isRunning}
              />
            );
          case "Cancel":
            return (
              <BitcoinPossiblyCancelledAlert
                timelock={timelock}
                swap={swap}
              />
            );
          case "Punish":
            return <PunishTimelockExpiredAlert />;
          default:
            exhaustiveGuard(timelock);
        }
      }
      return <PunishTimelockExpiredAlert />;

    // If the Bitcoin lock transaction has not been published yet
    // there is no need to display an alert
    case BobStateName.BtcLockReadyToPublish:
      return null;
    default:
      exhaustiveGuard(swap.state_name);
  }
}

// How many blocks need to be left for the timelock to be considered unusual
// A bit arbitrary but we don't want to alarm the user
// 72 is the default cancel timelock in blocks
// 4 blocks are around 40 minutes
// If the swap has taken longer than 40 minutes, we consider it unusual
const UNUSUAL_AMOUNT_OF_TIME_HAS_PASSED_THRESHOLD = 72 - 4;

/**
 * Main component for displaying the swap status alert.
 * @param swap - The swap information.
 * @returns JSX.Element | null
 */
export default function SwapStatusAlert({
  swap,
  onlyShowIfUnusualAmountOfTimeHasPassed,
}: {
  swap: GetSwapInfoResponseExt;
  onlyShowIfUnusualAmountOfTimeHasPassed?: boolean;
}) {
  const timelock = useAppSelector(selectSwapTimelock(swap.swap_id));

  if (!isGetSwapInfoResponseRunningSwap(swap)) {
    return null;
  }

  if (timelock == null) {
    return null;
  }

  const hasUnusualAmountOfTimePassed =
    timelock.type === "None" &&
    timelock.content.blocks_left > UNUSUAL_AMOUNT_OF_TIME_HAS_PASSED_THRESHOLD;

  if (onlyShowIfUnusualAmountOfTimeHasPassed && hasUnusualAmountOfTimePassed) {
    return null;
  }

  const isRunning = useIsSpecificSwapRunning(swap.swap_id);

  return (
    <Alert
      key={swap.swap_id}
      severity="warning"
      variant="filled"
      classes={{ message: "alert-message-flex-grow" }}
      sx={{
        "& .alert-message-flex-grow": {
          flexGrow: 1,
        },
      }}
    >
      <AlertTitle>
        {isRunning ? (
          hasUnusualAmountOfTimePassed ? (
            "Swap has been running for a while"
          ) : (
            "Swap is running"
          )
        ) : (
          <>
            Swap <TruncatedText>{swap.swap_id}</TruncatedText> is
            not running
          </>
        )}
      </AlertTitle>
      <Box
        sx={{
          display: "flex",
          flexDirection: "column",
          gap: 1,
        }}
      >
        <StateAlert swap={swap} timelock={timelock} isRunning={isRunning} />
        <TimelockTimeline swap={swap} timelock={timelock} />
      </Box>
    </Alert>
  );
}