package main

import (
    "fmt"
    "github.com/noodlehaus/stash"
)

// our fake db connection
type mockDatabase struct{ id int }

// our demo custom resource
type customResource struct{ id int }

func main() {
    sharedDemo()
    factoryDemo()
    protectedDemo()
}

func sharedDemo() {

    // fake changing state
    id := 0

    // db connection loader is shared (ala singleton)
    database, _ := stash.Shared(func() *mockDatabase {
        // trigger state change
        id++
        return &mockDatabase{id: id}
    })

    // create stash and put in loader
    resources := stash.New()
    resources.Store("database", database)

    res1, _ := resources.Fetch("database")
    con1 := res1.(*mockDatabase)

    res2, _ := resources.Fetch("database")
    con2 := res2.(*mockDatabase)

    // these 2 should have the same values because of stash.Shared()
    fmt.Printf("db id: %d\n", con1.id)
    fmt.Printf("db id: %d\n", con2.id)
}

func factoryDemo() {

    // fake changing state
    id := 0

    // create our resource factory
    factory, _ := stash.Factory(func() *customResource {
        id++
        return &customResource{id: id}
    })

    // create stash and inject resource
    resources := stash.New()
    resources.Store("resource", factory)

    res1, _ := resources.Fetch("resource")
    obj1 := res1.(*customResource)

    res2, _ := resources.Fetch("resource")
    obj2 := res2.(*customResource)

    // these 2 should NOT have the same values because of stash.Factory()
    fmt.Printf("resource id: %d\n", obj1.id)
    fmt.Printf("resource id: %d\n", obj2.id)
}

func protectedDemo() {

    // let's store a func() value
    foo, _ := stash.Protected(func() {
        fmt.Println("Hello, world!")
    })

    // store our func in stash
    resources := stash.New()
    resources.Store("foo", foo)

    // fetch and use it
    res, _ := resources.Fetch("foo")
    res.(func())()
}