/**
 * Type-level tests for template key type inference
 *
 * These tests verify compile-time type behavior of the cache system:
 * 1. Template key type inference works correctly
 * 2. Casual API blocks schema keys (including template patterns)
 * 3. Value types are correctly inferred from schema
 */

import type {
  ExpandTemplateKey,
  InferSharedCacheValue,
  InferUseCacheValue,
  IsTemplateKey,
  ProcessKey,
  SharedCacheKey,
  UseCacheCasualKey,
  UseCacheKey
} from '@shared/data/cache/cacheSchemas'
import { describe, expect, expectTypeOf, it } from 'vitest'

describe('Template Key Type Utilities', () => {
  describe('IsTemplateKey', () => {
    it('should detect template keys as true', () => {
      // Using expectTypeOf for type-level assertions
      const templateResult1: IsTemplateKey<'scroll.position.${id}'> = true
      const templateResult2: IsTemplateKey<'entity.cache.${type}_${id}'> = true
      expect(templateResult1).toBe(true)
      expect(templateResult2).toBe(true)
    })

    it('should detect fixed keys as false', () => {
      const fixedResult1: IsTemplateKey<'app.user.avatar'> = false
      const fixedResult2: IsTemplateKey<'chat.web_search.searching'> = false
      expect(fixedResult1).toBe(false)
      expect(fixedResult2).toBe(false)
    })
  })

  describe('ExpandTemplateKey', () => {
    it('should expand single placeholder', () => {
      // Type assertion: 'scroll.position.topic123' should extend the expanded type
      type Expanded = ExpandTemplateKey<'scroll.position.${id}'>
      const key1: Expanded = 'scroll.position.topic123'
      const key2: Expanded = 'scroll.position.abc'
      expect(key1).toBe('scroll.position.topic123')
      expect(key2).toBe('scroll.position.abc')
    })

    it('should expand multiple placeholders', () => {
      type Expanded = ExpandTemplateKey<'entity.cache.${type}_${id}'>
      const key1: Expanded = 'entity.cache.user_123'
      const key2: Expanded = 'entity.cache.post_456'
      expect(key1).toBe('entity.cache.user_123')
      expect(key2).toBe('entity.cache.post_456')
    })

    it('should leave fixed keys unchanged', () => {
      type Expanded = ExpandTemplateKey<'app.user.avatar'>
      const key: Expanded = 'app.user.avatar'
      expect(key).toBe('app.user.avatar')
    })
  })

  describe('ProcessKey', () => {
    it('should expand template keys', () => {
      type Processed = ProcessKey<'scroll.position.${topicId}'>
      const key: Processed = 'scroll.position.topic123'
      expect(key).toBe('scroll.position.topic123')
    })

    it('should keep fixed keys unchanged', () => {
      type Processed = ProcessKey<'app.user.avatar'>
      const key: Processed = 'app.user.avatar'
      expect(key).toBe('app.user.avatar')
    })
  })

  describe('UseCacheKey', () => {
    it('should include fixed keys', () => {
      const key1: UseCacheKey = 'app.user.avatar'
      const key2: UseCacheKey = 'chat.web_search.searching'
      expect(key1).toBe('app.user.avatar')
      expect(key2).toBe('chat.web_search.searching')
    })

    it('should match template patterns', () => {
      const key1: UseCacheKey = 'scroll.position.topic123'
      const key2: UseCacheKey = 'scroll.position.abc-def'
      const key3: UseCacheKey = 'entity.cache.user_456'
      expect(key1).toBe('scroll.position.topic123')
      expect(key2).toBe('scroll.position.abc-def')
      expect(key3).toBe('entity.cache.user_456')
    })
  })

  describe('InferUseCacheValue', () => {
    it('should infer value type for fixed keys', () => {
      // These type assertions verify the type system works
      const avatarType: InferUseCacheValue<'app.user.avatar'> = 'test'
      const generatingType: InferUseCacheValue<'chat.web_search.searching'> = true
      expectTypeOf(avatarType).toBeString()
      expectTypeOf(generatingType).toBeBoolean()
    })

    it('should infer value type for template key instances', () => {
      const scrollType: InferUseCacheValue<'scroll.position.topic123'> = 100
      const entityType: InferUseCacheValue<'entity.cache.user_456'> = { loaded: true, data: null }
      expectTypeOf(scrollType).toBeNumber()
      expectTypeOf(entityType).toMatchTypeOf<{ loaded: boolean; data: unknown }>()
    })

    it('should return never for unknown keys', () => {
      // Unknown key should infer to never
      type UnknownValue = InferUseCacheValue<'unknown.key.here'>
      expectTypeOf<UnknownValue>().toBeNever()
    })
  })

  describe('UseCacheCasualKey', () => {
    it('should block fixed schema keys', () => {
      // Fixed keys should resolve to never
      type BlockedFixed = UseCacheCasualKey<'app.user.avatar'>
      expectTypeOf<BlockedFixed>().toBeNever()
    })

    it('should block template pattern matches', () => {
      // Keys matching template patterns should resolve to never
      type BlockedTemplate = UseCacheCasualKey<'scroll.position.topic123'>
      expectTypeOf<BlockedTemplate>().toBeNever()
    })

    it('should allow non-schema keys', () => {
      // Non-schema keys should pass through
      type AllowedKey = UseCacheCasualKey<'my.custom.key'>
      const key: AllowedKey = 'my.custom.key'
      expect(key).toBe('my.custom.key')
    })
  })

  describe('Runtime template key detection', () => {
    it('should correctly detect template keys', () => {
      const isTemplate = (key: string) => key.includes('${') && key.includes('}')

      expect(isTemplate('scroll.position.${id}')).toBe(true)
      expect(isTemplate('entity.cache.${type}_${id}')).toBe(true)
      expect(isTemplate('app.user.avatar')).toBe(false)
      expect(isTemplate('chat.web_search.searching')).toBe(false)
    })
  })

  describe('SharedCacheKey', () => {
    it('should include fixed keys', () => {
      const key: SharedCacheKey = 'chat.web_search.active_searches'
      expect(key).toBe('chat.web_search.active_searches')
    })

    it('should match template patterns', () => {
      const key1: SharedCacheKey = 'web_search.provider.last_used_key.google'
      const key2: SharedCacheKey = 'ocr.provider.last_used_key.tesseract'
      expect(key1).toBe('web_search.provider.last_used_key.google')
      expect(key2).toBe('ocr.provider.last_used_key.tesseract')
    })
  })

  describe('InferSharedCacheValue', () => {
    it('should infer value type for fixed keys', () => {
      // 'chat.web_search.active_searches' -> CacheActiveSearches
      expectTypeOf<InferSharedCacheValue<'chat.web_search.active_searches'>>().toMatchTypeOf<Record<string, unknown>>()
    })

    it('should infer value type for template key instances', () => {
      const webSearchLastKey: InferSharedCacheValue<'web_search.provider.last_used_key.google'> = 'key-1'
      const ocrLastKey: InferSharedCacheValue<'ocr.provider.last_used_key.tesseract'> = 'key-2'
      expectTypeOf(webSearchLastKey).toBeString()
      expectTypeOf(ocrLastKey).toBeString()
    })

    it('should return never for unknown keys', () => {
      type UnknownValue = InferSharedCacheValue<'unknown.shared.key'>
      expectTypeOf<UnknownValue>().toBeNever()
    })
  })
})
