'use client';

import { useState } from "react";
import { 
  Box, Button, Typography, Paper, Stack, 
  TextField, MenuItem, IconButton, Grid, Divider 
} from "@mui/material";
import SaveIcon from "@mui/icons-material/Save";
import ArrowBackIcon from '@mui/icons-material/ArrowBack';
import AssignmentIcon from '@mui/icons-material/Assignment';
import AddCircleOutlineIcon from '@mui/icons-material/AddCircleOutline';
import DeleteOutlineIcon from '@mui/icons-material/DeleteOutline';
import FolderIcon from "@mui/icons-material/Folder";
import { useRouter } from "next/navigation";
import { updateFileAction } from "./_actions";

interface MetadataPair {
  key: string;
  value: string;
}

export default function UpdateView({ fileNode, folders }: any) {
  const router = useRouter();
  const [loading, setLoading] = useState(false);

  // 1. Initialize Basic Info
  const [name, setName] = useState(fileNode.name);
  const [description, setDescription] = useState(fileNode.description || "");
  const [parentId, setParentId] = useState(fileNode.parentId || "");

  // 2. Parse existing JSON metadata into Key/Value array for the UI
  // We filter out 'type' and 'mimeType' as they are system-managed
  const initialMetadata = Object.entries(fileNode.metadata || {})
    .filter(([key]) => !['type', 'mimeType'].includes(key))
    .map(([key, value]) => ({ key, value: String(value) }));

  const [customMetadata, setCustomMetadata] = useState<MetadataPair[]>(initialMetadata);

  const handleUpdate = async () => {
    setLoading(true);
    const formData = new FormData();
    formData.append("id", fileNode.id);
    formData.append("name", name);
    formData.append("description", description);
    formData.append("parentId", parentId);
    
    // Convert array back to object for storage
    const metadataObj = customMetadata.reduce((acc, curr) => {
      if (curr.key.trim()) acc[curr.key.trim()] = curr.value;
      return acc;
    }, {} as Record<string, string>);
    
    formData.append("customMetadata", JSON.stringify(metadataObj));

    const res = await updateFileAction(formData);
    if (res.success) {
      router.push("/dashboard");
      router.refresh();
    } else {
      alert("Update failed");
      setLoading(false);
    }
  };

  return (
    <Paper sx={{ p: { xs: 3, md: 6 }, borderRadius: 4 }} elevation={3}>
      <Button startIcon={<ArrowBackIcon />} onClick={() => router.back()} sx={{ mb: 2 }}>
        Back
      </Button>

      <Typography variant="h4" fontWeight={900} color="primary" gutterBottom>
        Edit File Details
      </Typography>

      <Stack spacing={4} sx={{ mt: 2 }}>
        {/* Name Field */}
        <TextField 
          label="File Name" 
          fullWidth value={name} 
          onChange={(e) => setName(e.target.value)}
          slotProps={{ inputLabel: { shrink: true } }}
        />

        {/* Folder Select */}
        <TextField
          id="update-dest-select"
          select fullWidth label="Destination Folder"
          value={parentId}
          onChange={(e) => setParentId(e.target.value)}
          slotProps={{
            select: { displayEmpty: true },
            inputLabel: { shrink: true }
          }}
        >
          <MenuItem value=""><em>-- Root --</em></MenuItem>
          {folders.map((f: any) => (
            <MenuItem key={f.id} value={f.id}>{f.name}</MenuItem>
          ))}
        </TextField>

        {/* Custom Metadata Section */}
        <Box>
          <Box sx={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', mb: 2 }}>
            <Typography variant="h6" fontWeight="700" sx={{ display: 'flex', alignItems: 'center', gap: 1 }}>
              <AssignmentIcon color="primary" /> Custom Attributes
            </Typography>
            <Button 
              startIcon={<AddCircleOutlineIcon />} 
              size="small" 
              onClick={() => setCustomMetadata([...customMetadata, { key: "", value: "" }])}
            >
              Add Field
            </Button>
          </Box>
          
          <Stack spacing={2}>
            {customMetadata.map((row, index) => (
              <Grid container spacing={1} key={index} alignItems="center">
                <Grid size={ {xs:5}}>
                  <TextField 
                    fullWidth size="small" placeholder="Key" 
                    value={row.key} 
                    onChange={(e) => {
                      const updated = [...customMetadata];
                      updated[index].key = e.target.value;
                      setCustomMetadata(updated);
                    }}
                  />
                </Grid>
                <Grid size={{xs:6}}>
                  <TextField 
                    fullWidth size="small" placeholder="Value" 
                    value={row.value} 
                    onChange={(e) => {
                      const updated = [...customMetadata];
                      updated[index].value = e.target.value;
                      setCustomMetadata(updated);
                    }}
                  />
                </Grid>
                <Grid size={{xs:1}}>
                  <IconButton color="error" onClick={() => setCustomMetadata(customMetadata.filter((_, i) => i !== index))}>
                    <DeleteOutlineIcon />
                  </IconButton>
                </Grid>
              </Grid>
            ))}
          </Stack>
        </Box>

        <TextField
          label="Description"
          multiline rows={4} fullWidth
          value={description}
          onChange={(e) => setDescription(e.target.value)}
          slotProps={{ inputLabel: { shrink: true } }}
        />

        <Button 
          variant="contained" size="large" fullWidth
          startIcon={<SaveIcon />}
          onClick={handleUpdate}
          disabled={loading}
          sx={{ py: 1.5, fontWeight: 'bold' }}
        >
          {loading ? "Saving..." : "Save Changes"}
        </Button>
      </Stack>
    </Paper>
  );
}