import type { ImplBlock, KindBadge, LibraryRule, PropertyRow, RuleCard, TraitBlock } from '../contract'
import { implRows, plainSay, traitRows } from './rustRows'

/** 和函数卡同一个黄，实现块看起来仍是函数那一挂。 */
const IMPL: KindBadge = { label: '实现', color: { dark: '#dcdcaa', light: '#795e26' }, icon: 'square-function' }
/** 和声明关键字同一个蓝，同特质这个种类在预览里的颜色。 */
const TRAIT: KindBadge = { label: '特质', color: { dark: '#569cd6', light: '#0000ff' }, icon: 'network' }

/**
 * impl、trait 的方法表：点方法名展开那张函数卡，函数体各句在卡里。
 * 方法挂在方法表的子行上（RuleSlot）。不看导入，Rust 文件都启用。
 */
export const rustImplRule: LibraryRule = {
  id: 'rust',
  label: 'Rust 实现与特质',
  languageIds: ['rust'],
  libraries: [],
  claim: (block, context) => {
    const say = plainSay(context.doc)
    if (block.kind === 'impl')
      return methodsCard(block, 'rust.impl', IMPL, implRows(block, say))
    if (block.kind === 'trait')
      return methodsCard(block, 'rust.trait', TRAIT, traitRows(block, say))
    return undefined
  },
  attributeNames: () => ({
    attributes: {},
    values: { kind: { 'rust.impl': '实现', 'rust.trait': '特质' } },
  }),
}

/** 带方法表的卡片：子块里的每个函数挂在「方法」那一行讲它的子行上，跟 rows 里的顺序一一对上。 */
function methodsCard(block: ImplBlock | TraitBlock, kind: string, badge: KindBadge, rows: PropertyRow[]): RuleCard {
  const row = rows.findIndex(item => item.label === '方法')
  const methods = block.children.filter(child => child.kind === 'function')
  return {
    kind,
    badge,
    rows,
    ...(block.facts.name && { defines: { startIndex: block.facts.name.startIndex, endIndex: block.facts.name.endIndex } }),
    absorbs: [],
    ...(row >= 0 && { slots: methods.map((child, item) => ({ block: child, row, item })) }),
  }
}