/**
 * @license
 * Copyright 2025 Qwen
 * SPDX-License-Identifier: Apache-2.0
 */

import { useState, useMemo, useEffect } from 'react';
import { Box, Text } from 'ink';
import { RadioButtonSelect } from '../../shared/RadioButtonSelect.js';
import { ToolCategory } from '../types.js';
import { Kind, Config } from '@qwen-code/qwen-code-core';
import { Colors } from '../../../colors.js';

interface ToolOption {
  label: string;
  value: string;
  category: ToolCategory;
}

interface ToolSelectorProps {
  tools?: string[];
  onSelect: (tools: string[]) => void;
  config: Config | null;
}

/**
 * Tool selection with categories.
 */
export function ToolSelector({
  tools = [],
  onSelect,
  config,
}: ToolSelectorProps) {
  // Generate tool categories from actual tool registry
  const {
    toolCategories,
    readTools,
    editTools,
    executeTools,
    initialCategory,
  } = useMemo(() => {
    if (!config) {
      // Fallback categories if config not available
      return {
        toolCategories: [
          {
            id: 'all',
            name: 'All Tools (Default)',
            tools: [],
          },
        ],
        readTools: [],
        editTools: [],
        executeTools: [],
        initialCategory: 'all',
      };
    }

    const toolRegistry = config.getToolRegistry();
    const allTools = toolRegistry.getAllTools();

    // Categorize tools by Kind
    const readTools = allTools
      .filter(
        (tool) =>
          tool.kind === Kind.Read ||
          tool.kind === Kind.Search ||
          tool.kind === Kind.Fetch ||
          tool.kind === Kind.Think,
      )
      .map((tool) => tool.displayName)
      .sort();

    const editTools = allTools
      .filter(
        (tool) =>
          tool.kind === Kind.Edit ||
          tool.kind === Kind.Delete ||
          tool.kind === Kind.Move,
      )
      .map((tool) => tool.displayName)
      .sort();

    const executeTools = allTools
      .filter((tool) => tool.kind === Kind.Execute)
      .map((tool) => tool.displayName)
      .sort();

    const toolCategories = [
      {
        id: 'all',
        name: 'All Tools',
        tools: [],
      },
      {
        id: 'read',
        name: 'Read-only Tools',
        tools: readTools,
      },
      {
        id: 'edit',
        name: 'Read & Edit Tools',
        tools: [...readTools, ...editTools],
      },
      {
        id: 'execute',
        name: 'Read & Edit & Execution Tools',
        tools: [...readTools, ...editTools, ...executeTools],
      },
    ].filter((category) => category.id === 'all' || category.tools.length > 0);

    // Determine initial category based on tools prop
    let initialCategory = 'all'; // default to first option

    if (tools.length === 0) {
      // Empty array represents all tools
      initialCategory = 'all';
    } else {
      // Try to match tools array to a category
      const matchingCategory = toolCategories.find((category) => {
        if (category.id === 'all') return false;

        // Check if the tools array exactly matches this category's tools
        const categoryToolsSet = new Set(category.tools);
        const inputToolsSet = new Set(tools);

        return (
          categoryToolsSet.size === inputToolsSet.size &&
          [...categoryToolsSet].every((tool) => inputToolsSet.has(tool))
        );
      });

      if (matchingCategory) {
        initialCategory = matchingCategory.id;
      }
      // If no exact match found, keep default 'all'
    }

    return {
      toolCategories,
      readTools,
      editTools,
      executeTools,
      initialCategory,
    };
  }, [config, tools]);

  const [selectedCategory, setSelectedCategory] =
    useState<string>(initialCategory);

  // Update selected category when initialCategory changes (when tools prop changes)
  useEffect(() => {
    setSelectedCategory(initialCategory);
  }, [initialCategory]);

  const toolOptions: ToolOption[] = toolCategories.map((category) => ({
    label: category.name,
    value: category.id,
    category,
  }));

  const handleHighlight = (selectedValue: string) => {
    setSelectedCategory(selectedValue);
  };

  const handleSelect = (selectedValue: string) => {
    const category = toolCategories.find((cat) => cat.id === selectedValue);
    if (category) {
      if (category.id === 'all') {
        onSelect([]); // Empty array for 'all'
      } else {
        onSelect(category.tools);
      }
    }
  };

  // Get the currently selected category for displaying tools
  const currentCategory = toolCategories.find(
    (cat) => cat.id === selectedCategory,
  );

  return (
    <Box flexDirection="column" gap={1}>
      <Box flexDirection="column">
        <RadioButtonSelect
          items={toolOptions.map((option) => ({
            label: option.label,
            value: option.value,
          }))}
          initialIndex={toolOptions.findIndex(
            (opt) => opt.value === selectedCategory,
          )}
          onSelect={handleSelect}
          onHighlight={handleHighlight}
          isFocused={true}
        />
      </Box>

      {/* Show help information or tools for selected category */}
      {currentCategory && (
        <Box flexDirection="column">
          {currentCategory.id === 'all' ? (
            <Text color={Colors.Gray}>
              All tools selected, including MCP tools
            </Text>
          ) : currentCategory.tools.length > 0 ? (
            <>
              <Text color={Colors.Gray}>Selected tools:</Text>
              <Box flexDirection="column" marginLeft={2}>
                {(() => {
                  // Filter the already categorized tools to show only those in current category
                  const categoryReadTools = currentCategory.tools.filter(
                    (tool) => readTools.includes(tool),
                  );
                  const categoryEditTools = currentCategory.tools.filter(
                    (tool) => editTools.includes(tool),
                  );
                  const categoryExecuteTools = currentCategory.tools.filter(
                    (tool) => executeTools.includes(tool),
                  );

                  return (
                    <>
                      {categoryReadTools.length > 0 && (
                        <Text color={Colors.Gray}>
                          • Read-only tools: {categoryReadTools.join(', ')}
                        </Text>
                      )}
                      {categoryEditTools.length > 0 && (
                        <Text color={Colors.Gray}>
                          • Edit tools: {categoryEditTools.join(', ')}
                        </Text>
                      )}
                      {categoryExecuteTools.length > 0 && (
                        <Text color={Colors.Gray}>
                          • Execution tools: {categoryExecuteTools.join(', ')}
                        </Text>
                      )}
                    </>
                  );
                })()}
              </Box>
            </>
          ) : null}
        </Box>
      )}
    </Box>
  );
}