// root module
import { CacheModule } from 'nestjs-omacache'

@Module({
    // this import enables set-on-start caching
    imports: [CacheModule],
    ...
})
export class AppModule {}

// imported 'Cache' is factory to receive storage that implements ICacheStorage
import { Cache, ICacheStorage } from "nestjs-omacache";

// for example, we can use redis for storage
// What ever your implementation is, it must satisfies ICacheStorage interface.
// set() ttl param is optional, but implementing signature including ttl is strongly recommended
class RedisStorage implements ICacheStorage {
    get(key: string) {...}
    set(key: string, val: any, ttl: number) {...}
    has(key: string) {...}
    delete(key: string) {...}
}

// Then you can make External Redis Cache!
const ExternalCache = Cache({ storage: new RedisStorage() })

// ...or
// you can just initialize it using default storage(in-memory cache)
// default storage is based on lru-cache package, so it can handle TTL and cache eviction
// default max size is 10000
// make sure you are not making memory overhead by using default in-memory storage
const InMemoryCache = Cache();

// you can implement your custom in-memory cache, which is more configurable.

// regardless class is Controller or Injectable, you can use produced cache decorator
@Controller()
class AppController {
    @Get()
    @ExternalCache({
        // persistent cache also needs key to control cache internally
        key: 'some key',
        // persistent cache sets cache automatically on server start
        kind: 'persistent',
        // refresh interval is optional
        // use it if you want cache refreshing
        refreshIntervalSec: 60 * 60 * 3 // 3 hours
    })
    async noParameterMethod() {
        ...
    }

    @Get('/:id')
    @ExternalCache({
        key: 'other key',
        kind: 'temporal',
        ttl: 10 * MIN, // 10 mins
        // You have to specify parameter indexes which will be referenced dynamically
        // In this case, cache key will be concatenated string of key, id param, q2 query
        paramIndex: [0, 2]
    })
    async haveParametersMethod(
        @Param('id') id: number,
        // q1 will not affect cache key because paramIndex is specified to refer param index 0 and 2
        @Query('query_1') q1: string,
        @Query('query_2') q2: string
    ) {
        ...
    }
}

// let's say SomeService have three methods: taskA, taskB, taskC
// assume that taskA and taskC can be cached, but taskB not
// each of task takes 1 second to complete

// in this scenario, @Nestjs/cache-manager can't handle caching because it's stick with interceptor
// but we can cover this case using partial caching
@Injectable()
class SomeService {

    @InMemoryCache(...)
    taskA() {} // originally takes 1 second

    // not cacheable
    taskB() {} // takes 1 second

    @InMemoryCache(...)
    taskC() {} // originally takes 1 second
}


@Controller()
class SomeController {
    constructor(
        private someService: SomeService
    ) {}

    // this route can take slightest time because taskA and taskC is partially cached
    // execution time can be reduced 3 seconds to 1 second
    @Get()
    route1() {
        someService.taskA(); // takes no time
        someService.taskB(); // still takes 1 second
        someService.taskC(); // takes no time
    }
}

// we need to set same key to set & unset cache
// keep in mind that cache control by parameters is supported for temporal cache only
@Controller()
class SomeController {
    @Get()
    @InMemoryCache({
        key: 'hello',
        kind: 'persistent',
    })
    getSomethingHeavy() {
        ...
    }

    @Put()
    // in this case, we are busting persistent cache
    // after busting persistent cache, when busting method is done,
    // persistent cached method(getSomethingHeavy in this case) will invoked immediately
    // so you can still get the updated cache from persistent cache route!
    @InMemoryCache({
        key: 'hello',
        kind: 'bust',
    })
    updateSomethingHeavy() {
        ...
    }


    // this route sets cache for key 'some'
    @Get('/some')
    @InMemoryCache({
        key: 'some',
        kind:'temporal',
        ttl: 30 * SECOND, // 30 seconds
    })
    getSome() {
        ...
    }

    // and this route will unset cache for key 'some', before the 'some' cache's ttl expires
    @Patch('/some')
    @InMemoryCache({
        key: 'some',
        kind: 'bust',
    })
    updateSome() {
        ...
    }

    // above operation also can handle parameter based cache
    @Get('/:p1/:p2')
    @ExternalCache({
        key: 'some',
        kind:'temporal',
        ttl: 30 * SECOND, // 30 seconds
        paramIndex: [0, 1]
    })
    getSomeOther(@Param('p1') p1: string, @Param('p2') p2: string) {
        ...
    }

    // will unset cache of some + p1 + p2
    @Patch('/:p1/:p2')
    @ExternalCache({
        key: 'some',
        kind: 'bust',
        paramIndex: [0, 1]
    })
    updateSomeOther(@Param('p1') p1: string, @Param('p2') p2: string) {
        ...
    }

    // if you want to unset all cache based on a key, you can use bustAllChildren option.
    // this will only work for temporal cache.
    @Get('/foo')
    @ExternalCache({
        key: 'foo',
        kind: 'temporal',
        ttl: 30 * SECOND,
    })
    getFoo() {
        ...
    }

    @Get('foo/:p1/:p2')
    @ExternalCache({
        key: 'foo',
        kind: 'temporal',
        ttl: 30 * SECOND,
        paramIndex: [0, 1]
    })
    getFooOther(@Param('p1') p1: string, @Param('p2') p2: string) {
        ...
    }

    @Patch('/foo')
    @ExternalCache({
        key: 'foo',
        kind: 'bust',
        bustAllChildren: true
    })
    updateFoo() {
        ...
    }
}

@Put("/users/:userId")
@InMemoryCache({
    kind: "bust",
    key: "user",
    paramIndex:[0],
    // additional bustings
    // It's same type of "bust" but except kind & addition
    addition: [
        {
            key: "my_page",
            // this would not remove cache if
            // route that sets "my_page" cache construct cache key with different parameter poisition
            paramIndex:[0]
        },
        {
            key: "friends",
            bustAllChildren: true
        }
    ]
})
modifyUser(@Param("userId") userId: string, @Body() body: any) {
    ...
}