/**
 * @ai-summary Review screen for extracted maintenance schedules from manual OCR
 * @ai-context Dialog showing extracted items with checkboxes, inline editing, batch create
 */

import React, { useState, useCallback } from 'react';
import {
  Dialog,
  DialogTitle,
  DialogContent,
  DialogActions,
  Button,
  Box,
  Typography,
  TextField,
  Checkbox,
  IconButton,
  Alert,
  CircularProgress,
  Tooltip,
  useTheme,
  useMediaQuery,
} from '@mui/material';
import EditIcon from '@mui/icons-material/Edit';
import CheckIcon from '@mui/icons-material/Check';
import CloseIcon from '@mui/icons-material/Close';
import SelectAllIcon from '@mui/icons-material/SelectAll';
import DeselectIcon from '@mui/icons-material/Deselect';
import WarningAmberIcon from '@mui/icons-material/WarningAmber';
import type { MaintenanceScheduleItem } from '../../documents/hooks/useManualExtraction';
import { useCreateSchedulesFromExtraction } from '../hooks/useCreateSchedulesFromExtraction';
import { SubtypeCheckboxGroup } from './SubtypeCheckboxGroup';
import { getSubtypesForCategory } from '../types/maintenance.types';

export interface MaintenanceScheduleReviewScreenProps {
  open: boolean;
  items: MaintenanceScheduleItem[];
  vehicleId: string;
  onClose: () => void;
  onCreated: (count: number) => void;
}

interface EditableItem extends MaintenanceScheduleItem {
  selected: boolean;
}

const ConfidenceIndicator: React.FC<{ confidence: number }> = ({ confidence }) => {
  const filledDots = Math.round(confidence * 4);
  const isLow = confidence < 0.6;

  return (
    <Box
      sx={{ display: 'flex', gap: 0.25, ml: 1 }}
      aria-label={`Confidence: ${Math.round(confidence * 100)}%`}
    >
      {[0, 1, 2, 3].map((i) => (
        <Box
          key={i}
          sx={{
            width: 6,
            height: 6,
            borderRadius: '50%',
            backgroundColor: i < filledDots
              ? (isLow ? 'warning.main' : 'success.main')
              : 'grey.300',
          }}
        />
      ))}
    </Box>
  );
};

interface InlineFieldProps {
  label: string;
  value: string | number | null;
  type?: 'text' | 'number';
  onSave: (value: string | number | null) => void;
  suffix?: string;
}

const InlineField: React.FC<InlineFieldProps> = ({ label, value, type = 'text', onSave, suffix }) => {
  const [isEditing, setIsEditing] = useState(false);
  const [editValue, setEditValue] = useState(value !== null ? String(value) : '');

  const displayValue = value !== null
    ? (suffix ? `${value} ${suffix}` : String(value))
    : '-';

  const handleSave = () => {
    let parsed: string | number | null = editValue || null;
    if (type === 'number' && editValue) {
      const num = parseFloat(editValue);
      parsed = isNaN(num) ? null : num;
    }
    onSave(parsed);
    setIsEditing(false);
  };

  const handleCancel = () => {
    setEditValue(value !== null ? String(value) : '');
    setIsEditing(false);
  };

  if (isEditing) {
    return (
      <Box sx={{ display: 'flex', alignItems: 'center', gap: 0.5 }}>
        <Typography variant="caption" color="text.secondary" sx={{ minWidth: 50, flexShrink: 0 }}>
          {label}:
        </Typography>
        <TextField
          size="small"
          value={editValue}
          onChange={(e) => setEditValue(e.target.value)}
          type={type === 'number' ? 'number' : 'text'}
          inputProps={{ step: type === 'number' ? 1 : undefined }}
          autoFocus
          sx={{ flex: 1, '& .MuiInputBase-input': { py: 0.5, px: 1, fontSize: '0.875rem' } }}
          onKeyDown={(e) => {
            if (e.key === 'Enter') handleSave();
            if (e.key === 'Escape') handleCancel();
          }}
        />
        <IconButton size="small" onClick={handleSave} color="primary" sx={{ minWidth: 44, minHeight: 44 }}>
          <CheckIcon sx={{ fontSize: 16 }} />
        </IconButton>
        <IconButton size="small" onClick={handleCancel} sx={{ minWidth: 44, minHeight: 44 }}>
          <CloseIcon sx={{ fontSize: 16 }} />
        </IconButton>
      </Box>
    );
  }

  return (
    <Box
      sx={{
        display: 'flex',
        alignItems: 'center',
        gap: 0.5,
        cursor: 'pointer',
        minHeight: 44,
        '&:hover .edit-icon': { opacity: 1 },
      }}
      onClick={() => setIsEditing(true)}
      role="button"
      tabIndex={0}
      aria-label={`Edit ${label}`}
      onKeyDown={(e) => {
        if (e.key === 'Enter' || e.key === ' ') {
          e.preventDefault();
          setIsEditing(true);
        }
      }}
    >
      <Typography variant="caption" color="text.secondary" sx={{ minWidth: 50, flexShrink: 0 }}>
        {label}:
      </Typography>
      <Typography
        variant="body2"
        sx={{
          fontWeight: value !== null ? 500 : 400,
          color: value !== null ? 'text.primary' : 'text.disabled',
        }}
      >
        {displayValue}
      </Typography>
      <EditIcon className="edit-icon" sx={{ fontSize: 14, opacity: 0, transition: 'opacity 0.2s', color: 'text.secondary' }} />
    </Box>
  );
};

export const MaintenanceScheduleReviewScreen: React.FC<MaintenanceScheduleReviewScreenProps> = ({
  open,
  items,
  vehicleId,
  onClose,
  onCreated,
}) => {
  const theme = useTheme();
  const isMobile = useMediaQuery(theme.breakpoints.down('sm'));
  const createMutation = useCreateSchedulesFromExtraction();

  const validRoutineSubtypes = getSubtypesForCategory('routine_maintenance');
  const [editableItems, setEditableItems] = useState<EditableItem[]>(() =>
    items.map((item) => ({
      ...item,
      subtypes: item.subtypes.filter((st) => validRoutineSubtypes.includes(st)),
      selected: true,
    }))
  );
  const [createError, setCreateError] = useState<string | null>(null);

  const selectedCount = editableItems.filter((i) => i.selected).length;
  const hasInvalidSubtypes = editableItems.some((i) => i.selected && i.subtypes.length === 0);
  const hasInvalidIntervals = editableItems.some(
    (i) => i.selected && i.intervalMiles === null && i.intervalMonths === null
  );

  const handleToggle = useCallback((index: number) => {
    setEditableItems((prev) =>
      prev.map((item, i) => (i === index ? { ...item, selected: !item.selected } : item))
    );
  }, []);

  const handleSelectAll = useCallback(() => {
    setEditableItems((prev) => prev.map((item) => ({ ...item, selected: true })));
  }, []);

  const handleDeselectAll = useCallback(() => {
    setEditableItems((prev) => prev.map((item) => ({ ...item, selected: false })));
  }, []);

  const handleFieldUpdate = useCallback((index: number, field: keyof MaintenanceScheduleItem, value: string | number | null) => {
    setEditableItems((prev) =>
      prev.map((item, i) => (i === index ? { ...item, [field]: value } : item))
    );
  }, []);

  const handleSubtypesChange = useCallback((index: number, subtypes: string[]) => {
    setEditableItems((prev) =>
      prev.map((item, i) => (i === index ? { ...item, subtypes } : item))
    );
  }, []);

  const handleCreate = async () => {
    setCreateError(null);
    const selectedItems = editableItems.filter((i) => i.selected);
    if (selectedItems.length === 0) return;

    try {
      await createMutation.mutateAsync({ vehicleId, items: selectedItems });
      onCreated(selectedItems.length);
    } catch (err: any) {
      setCreateError(err?.message || 'Failed to create maintenance schedules');
    }
  };

  const isEmpty = items.length === 0;

  return (
    <Dialog
      open={open}
      onClose={onClose}
      maxWidth="md"
      fullWidth
      fullScreen={isMobile}
      PaperProps={{
        sx: { maxHeight: isMobile ? '100vh' : '90vh' },
      }}
    >
      <DialogTitle sx={{ display: 'flex', alignItems: 'center', justifyContent: 'space-between' }}>
        <Typography variant="h6" component="span">
          Extracted Maintenance Schedules
        </Typography>
        <IconButton onClick={onClose} size="small" aria-label="Close">
          <CloseIcon />
        </IconButton>
      </DialogTitle>

      <DialogContent dividers>
        {isEmpty ? (
          <Box sx={{ textAlign: 'center', py: 6 }}>
            <Typography variant="h6" color="text.secondary" gutterBottom>
              No maintenance items found
            </Typography>
            <Typography variant="body2" color="text.secondary">
              The manual did not contain any recognizable routine maintenance schedules.
            </Typography>
          </Box>
        ) : (
          <>
            <Box sx={{ display: 'flex', alignItems: 'center', justifyContent: 'space-between', mb: 2 }}>
              <Typography variant="body2" color="text.secondary">
                {selectedCount} of {editableItems.length} items selected
              </Typography>
              <Box sx={{ display: 'flex', gap: 1 }}>
                <Button
                  size="small"
                  startIcon={<SelectAllIcon />}
                  onClick={handleSelectAll}
                  disabled={selectedCount === editableItems.length}
                >
                  Select All
                </Button>
                <Button
                  size="small"
                  startIcon={<DeselectIcon />}
                  onClick={handleDeselectAll}
                  disabled={selectedCount === 0}
                >
                  Deselect All
                </Button>
              </Box>
            </Box>

            <Box sx={{ display: 'flex', flexDirection: 'column', gap: 1 }}>
              {editableItems.map((item, index) => (
                <Box
                  key={index}
                  sx={{
                    display: 'flex',
                    alignItems: 'flex-start',
                    p: 1.5,
                    borderRadius: 1,
                    border: '1px solid',
                    borderColor: item.selected ? 'primary.light' : 'divider',
                    backgroundColor: item.selected ? 'primary.50' : 'transparent',
                    opacity: item.selected ? 1 : 0.6,
                    transition: 'all 0.15s ease',
                    '&:hover': { borderColor: 'primary.main' },
                  }}
                >
                  <Checkbox
                    checked={item.selected}
                    onChange={() => handleToggle(index)}
                    sx={{ mt: -0.5, mr: 1, '& .MuiSvgIcon-root': { fontSize: 24 }, minWidth: 44, minHeight: 44 }}
                    inputProps={{ 'aria-label': `Select ${item.service}` }}
                  />
                  <Box sx={{ flex: 1, minWidth: 0 }}>
                    <Box sx={{ display: 'flex', alignItems: 'center', mb: 0.5 }}>
                      <InlineField
                        label="Service"
                        value={item.service}
                        onSave={(v) => handleFieldUpdate(index, 'service', v)}
                      />
                      <ConfidenceIndicator confidence={item.confidence} />
                    </Box>

                    <Box sx={{
                      display: 'flex',
                      flexDirection: isMobile ? 'column' : 'row',
                      gap: isMobile ? 0.5 : 2,
                      alignItems: 'center',
                    }}>
                      <InlineField
                        label="Miles"
                        value={item.intervalMiles}
                        type="number"
                        onSave={(v) => handleFieldUpdate(index, 'intervalMiles', v)}
                        suffix="mi"
                      />
                      <InlineField
                        label="Months"
                        value={item.intervalMonths}
                        type="number"
                        onSave={(v) => handleFieldUpdate(index, 'intervalMonths', v)}
                        suffix="mo"
                      />
                      {item.selected && item.intervalMiles === null && item.intervalMonths === null && (
                        <Tooltip title="At least one interval (miles or months) is required">
                          <WarningAmberIcon color="warning" sx={{ fontSize: 18 }} />
                        </Tooltip>
                      )}
                    </Box>

                    {item.details && (
                      <Typography variant="caption" color="text.secondary" sx={{ display: 'block', mt: 0.5 }}>
                        {item.details}
                      </Typography>
                    )}

                    <Box sx={{ mt: 1 }}>
                      <Box sx={{ display: 'flex', alignItems: 'center', gap: 1, mb: 0.5 }}>
                        <Typography variant="caption" color="text.secondary">
                          Subtypes:
                        </Typography>
                        {item.subtypes.length === 0 && item.selected && (
                          <Tooltip title="At least one subtype is required">
                            <WarningAmberIcon color="warning" sx={{ fontSize: 18 }} />
                          </Tooltip>
                        )}
                      </Box>
                      <SubtypeCheckboxGroup
                        category="routine_maintenance"
                        selected={item.subtypes}
                        onChange={(subtypes) => handleSubtypesChange(index, subtypes)}
                      />
                    </Box>
                  </Box>
                </Box>
              ))}
            </Box>

            {hasInvalidSubtypes && (
              <Alert severity="warning" sx={{ mt: 2 }}>
                Some selected items are missing subtypes. Please select at least one subtype for each selected item.
              </Alert>
            )}

            {hasInvalidIntervals && (
              <Alert severity="warning" sx={{ mt: 2 }}>
                Some selected items are missing intervals. Please set at least one interval (miles or months) for each selected item.
              </Alert>
            )}

            <Typography variant="body2" color="text.secondary" sx={{ mt: 2, textAlign: 'center' }}>
              Tap any field to edit before creating schedules.
            </Typography>
          </>
        )}

        {createError && (
          <Alert severity="error" sx={{ mt: 2 }}>
            {createError}
          </Alert>
        )}
      </DialogContent>

      <DialogActions
        sx={{
          flexDirection: isMobile ? 'column' : 'row',
          gap: 1,
          p: 2,
        }}
      >
        <Button
          onClick={onClose}
          sx={{ order: isMobile ? 2 : 1, width: isMobile ? '100%' : 'auto' }}
        >
          {isEmpty ? 'Close' : 'Skip'}
        </Button>
        {!isEmpty && (
          <>
            <Box sx={{ flex: 1, display: isMobile ? 'none' : 'block' }} />
            <Button
              variant="contained"
              onClick={handleCreate}
              disabled={selectedCount === 0 || hasInvalidSubtypes || hasInvalidIntervals || createMutation.isPending}
              startIcon={createMutation.isPending ? <CircularProgress size={16} /> : <CheckIcon />}
              sx={{ minHeight: 44, order: isMobile ? 1 : 2, width: isMobile ? '100%' : 'auto' }}
            >
              {createMutation.isPending
                ? 'Creating...'
                : `Create ${selectedCount} Schedule${selectedCount !== 1 ? 's' : ''}`}
            </Button>
          </>
        )}
      </DialogActions>
    </Dialog>
  );
};

export default MaintenanceScheduleReviewScreen;
