import React, { useState, useEffect, useRef } from "react";
import { Box, Typography, CircularProgress, Alert, Paper } from "@mui/material";
import { useNavigate } from "react-router-dom";

// Starting messages with their timing
const STARTING_MESSAGES = [
  { message: "Initializing evaluation environment...", progress: 22 },
  { message: "Starting evaluation process...", progress: 54 },
  { message: "Evaluating models...", progress: 71 },
  { message: "Storing evaluation results...", progress: 100 },
];

const BenchmarkEvaluation = ({ sessionId, onComplete }) => {
  const [evaluationComplete, setEvaluationComplete] = useState(false);
  const [error, setError] = useState(null);
  const [elapsedTime, setElapsedTime] = useState(0);
  const [startingMessageIndex, setStartingMessageIndex] = useState(0);

  const timerIntervalRef = useRef(null);
  const startTimeRef = useRef(null);
  const startingMessageIntervalRef = useRef(null);
  const pollingIntervalRef = useRef(null);

  const navigate = useNavigate();

  // Add effect to handle automatic redirection when evaluation is complete
  useEffect(() => {
    if (evaluationComplete) {
      navigate(`/evaluation-display?session=${sessionId}`);
    }
  }, [evaluationComplete, sessionId, navigate]);

  // Add effect to handle starting messages
  useEffect(() => {
    startingMessageIntervalRef.current = setInterval(() => {
      setStartingMessageIndex((prev) => {
        if (prev < STARTING_MESSAGES.length - 1) {
          return prev + 1;
        }
        return prev;
      });
    }, 20000); // Change message every 20 seconds

    return () => {
      if (startingMessageIntervalRef.current) {
        clearInterval(startingMessageIntervalRef.current);
      }
    };
  }, []);

  // Start evaluation when component mounts
  useEffect(() => {
    // Set start time
    startTimeRef.current = Date.now();

    // Start timer
    timerIntervalRef.current = setInterval(() => {
      const timeElapsed = Math.floor(
        (Date.now() - startTimeRef.current) / 1000
      );
      setElapsedTime(timeElapsed);
    }, 1000);

    startEvaluation();

    // Clean up intervals on unmount
    return () => {
      if (pollingIntervalRef.current) {
        clearInterval(pollingIntervalRef.current);
      }
      if (timerIntervalRef.current) {
        clearInterval(timerIntervalRef.current);
      }
    };
  }, []);

  // Format elapsed time as HH:MM:SS
  const formatElapsedTime = () => {
    const hours = Math.floor(elapsedTime / 3600);
    const minutes = Math.floor((elapsedTime % 3600) / 60);
    const seconds = elapsedTime % 60;

    return [
      hours.toString().padStart(2, "0"),
      minutes.toString().padStart(2, "0"),
      seconds.toString().padStart(2, "0"),
    ].join(":");
  };

  // Start benchmark evaluation
  const startEvaluation = async () => {
    if (!sessionId) {
      setError("Missing session ID");
      return;
    }

    try {
      // Call API to start evaluation
      const response = await fetch("http://localhost:3001/evaluate-benchmark", {
        method: "POST",
        headers: {
          "Content-Type": "application/json",
        },
        body: JSON.stringify({
          session_id: sessionId,
        }),
      });

      const result = await response.json();

      if (response.ok) {
        // Set up polling to check completion
        pollingIntervalRef.current = setInterval(async () => {
          try {
            const logsResponse = await fetch(
              `http://localhost:3001/evaluation-logs/${sessionId}`
            );

            if (logsResponse.ok) {
              const logsResult = await logsResponse.json();
              if (logsResult.is_completed) {
                setEvaluationComplete(true);
                clearInterval(pollingIntervalRef.current);
              }
            }
          } catch (error) {
            console.log("Error polling logs:", error);
          }
        }, 2000);
      } else {
        setError(result.error || "Benchmark evaluation failed");
      }
    } catch (error) {
      console.error("Error starting evaluation:", error);
      setError("Error connecting to server");
    }
  };

  return (
    <Paper
      elevation={3}
      sx={{
        p: 4,
        mt: 3,
        mb: 3,
        display: "flex",
        flexDirection: "column",
        alignItems: "center",
        justifyContent: "center",
        minHeight: 200,
      }}
    >
      {error ? (
        <Alert severity="error" sx={{ width: "100%" }}>
          {error}
        </Alert>
      ) : (
        <>
          {evaluationComplete ? (
            <Alert severity="success" sx={{ width: "100%", mb: 3 }}>
              Evaluation completed successfully!
            </Alert>
          ) : (
            <>
              <CircularProgress size={60} sx={{ mb: 2 }} />
              <Typography variant="h6" component="div" gutterBottom>
                Benchmark evaluation...
              </Typography>

              {/* Step progress indicator */}
              <Typography variant="body1" color="text.secondary">
                {`${STARTING_MESSAGES[startingMessageIndex].message} (${STARTING_MESSAGES[startingMessageIndex].progress}%)`}
              </Typography>

              {/* Timer display */}
              <Box
                sx={{
                  display: "flex",
                  alignItems: "center",
                  mt: 1,
                  color: "text.secondary",
                  opacity: 0.5,
                }}
              >
                <Typography variant="body2">{formatElapsedTime()}</Typography>
              </Box>
            </>
          )}
        </>
      )}
    </Paper>
  );
};

export default BenchmarkEvaluation;