import React, { useState, useEffect } from "react";
import { useNavigate } from "react-router-dom";
import { useDispatch, useSelector } from "react-redux";
import {
  Container,
  Grid,
  Typography,
  CircularProgress,
  Box,
  Link,
  TextField,
  InputAdornment,
} from "@material-ui/core";
import { Button } from "@mui/material";
import { CloudUploadOutlined } from "@material-ui/icons";
import CloudDoneOutlinedIcon from "@mui/icons-material/CloudDoneOutlined";
import SyncIcon from "@material-ui/icons/Sync";
import { useDropzone } from "react-dropzone";
import api from "../services/api";
import { setUsername, setDataSource } from "../services/action";
const VERSION = require("../../package.json").version;

const UploadDiary = () => {
  const [file, setFile] = useState(null);
  const [uploading, setUploading] = useState(false);
  const [usernameInput, setUsernameInput] = useState("");
  const [syncing, setSyncing] = useState(false);
  const [syncError, setSyncError] = useState(null);
  const navigate = useNavigate();
  const dispatch = useDispatch();
  const storedUsername = useSelector((state) => state.username);

  useEffect(() => {
    if (storedUsername) setUsernameInput(storedUsername);
  }, [storedUsername]);

  useEffect(() => {
    const checkCSVFile = async () => {
      try {
        const response = await api.get("/api/check-csv");
        if (response.data.fileExists) {
          navigate("/PosterSelector");
        }
      } catch (error) {
        console.error("Error checking CSV file:", error);
      }
    };
    checkCSVFile();
  }, [navigate]);

  const { getRootProps, getInputProps } = useDropzone({
    onDrop: (acceptedFiles) => {
      setFile(acceptedFiles[0]);
    },
    maxFiles: 1,
    accept: ".csv",
  });

  const handleUpload = async () => {
    if (!file) return;
    setUploading(true);
    try {
      const formData = new FormData();
      formData.append("file", file);
      await api.post("/api/upload-csv", formData, {
        headers: { "Content-Type": "multipart/form-data" },
      });
      dispatch(setDataSource('csv'));
      navigate("/PosterSelector");
    } catch (error) {
      console.error("Error processing diary:", error);
    } finally {
      setUploading(false);
    }
  };

  const handleRssSync = async () => {
    const username = usernameInput.trim();
    if (!username) return;
    setSyncing(true);
    setSyncError(null);
    try {
      const res = await api.post("/api/sync-rss", { username });
      dispatch(setUsername(username));
      if (res.data.fresh) dispatch(setDataSource('rss'));
      navigate("/PosterSelector");
    } catch (err) {
      const msg = err.response?.data?.error || "Could not fetch RSS feed.";
      setSyncError(msg);
    } finally {
      setSyncing(false);
    }
  };

  return (
    <Box className="upload-page">
      <Container className="upload-diary">
        <div className="upload-card-wrapper">
        <div className="upload-card">
          <div className="logo-container">
            <img src="/icon.svg" alt="logo" className="logo" />
          </div>

          {/* CSV upload */}
          <Typography variant="h4" className="title">
            Upload Letterboxd Diary
          </Typography>
          <div {...getRootProps()} className="dropzone">
            <input {...getInputProps()} />
            {file ? (
              <>
                <CloudDoneOutlinedIcon className="dropzone-icon" />
                <Typography variant="h6" className="dropzone-text">
                  Your file has been uploaded: {file.name}
                </Typography>
              </>
            ) : (
              <>
                <CloudUploadOutlined className="dropzone-icon" />
                <Typography variant="h6" className="dropzone-text">
                  Drag and drop a CSV file here or click to select
                </Typography>
              </>
            )}
          </div>
          <Grid container justifyContent="center" className="progress-container">
            {uploading ? (
              <CircularProgress />
            ) : (
              <Button
                className="submit-button"
                variant="contained"
                onClick={handleUpload}
                disabled={!file}
              >
                SUBMIT
              </Button>
            )}
          </Grid>

          {/* Divider */}
          <div className="upload-divider">
            <span className="upload-divider-line" />
            <span className="upload-divider-text">or</span>
            <span className="upload-divider-line" />
          </div>

          {/* RSS sync */}
          <Typography variant="body1" className="rss-label">
            Sync from Letterboxd RSS
          </Typography>
          <div className="rss-row">
            <TextField
              className="rss-input"
              variant="outlined"
              size="small"
              placeholder="your-username"
              value={usernameInput}
              onChange={(e) => { setUsernameInput(e.target.value); setSyncError(null); }}
              onKeyDown={(e) => e.key === "Enter" && handleRssSync()}
              InputProps={{
                startAdornment: (
                  <InputAdornment position="start">
                    <span className="rss-url-prefix">letterboxd.com/</span>
                  </InputAdornment>
                ),
              }}
            />
            <Button
              className="rss-sync-button"
              variant="contained"
              onClick={handleRssSync}
              disabled={syncing || !usernameInput.trim()}
              startIcon={syncing ? <CircularProgress size={14} color="inherit" /> : <SyncIcon />}
            >
              {syncing ? "Syncing…" : "Sync"}
            </Button>
          </div>
          {syncError && (
            <Typography className="rss-error">{syncError}</Typography>
          )}
          <Typography className="rss-note">
            Syncs your ~50 most recent diary entries via the public RSS feed.
            Use CSV export for full history.
          </Typography>
        </div>
        </div>

        <Typography variant="body1" className="overview-text">
          This tool allows you to easily import your Letterboxd diary and select
          your favorite movie poster. Follow these simple steps:
          <br />
          <strong>1. Export your diary:</strong>{" "}
          <Link
            href="https://letterboxd.com/data/export/"
            target="_blank"
            rel="noopener noreferrer"
            className="link"
          >
            Export your Letterboxd data
          </Link>{" "}
          and extract the <code>diary.csv</code> file from the ZIP.
          <br />
          <strong>2. Upload the CSV:</strong> Drop your <code>diary.csv</code>{" "}
          file above or click to select it.
          <br />
          <strong>3. Poster Selection:</strong> After processing, you'll be
          redirected to the calendar where you can browse and choose your
          favorite poster for each movie.
        </Typography>
      </Container>
      <Box component="footer" className="footer">
        <Box className="footer-text">
          <Typography variant="body2" style={{ opacity: 0.7 }}>
            v{VERSION}
          </Typography>
          <Typography variant="body2" style={{ opacity: 0.5 }}>
            •
          </Typography>
          <Link
            href="https://github.com/Hugyouu/Letterboxd-Diary-Posters-Picker"
            target="_blank"
            rel="noopener noreferrer"
            className="link"
            onMouseEnter={(e) => (e.currentTarget.style.opacity = 1)}
            onMouseLeave={(e) => (e.currentTarget.style.opacity = 0.7)}
          >
            <span>Hugyouu</span>
          </Link>
        </Box>
      </Box>
    </Box>
  );
};

export default UploadDiary;