package pool_test

import (
	"code.squareroundforest.org/arpio/pool"
	"code.squareroundforest.org/arpio/syncbus"
	"code.squareroundforest.org/arpio/times"
	"testing"
	"time"
)

func TestAdaptive(t *testing.T) {
	t.Run("basic", func(t *testing.T) {
		t.Run("no concurrency", func(t *testing.T) {
			testBasicSet(t, scenarioOptions{})
		})

		t.Run("low concurrency", func(t *testing.T) {
			testBasicSet(t, scenarioOptions{concurrency: 8})
		})

		t.Run("high concurrency", func(t *testing.T) {
			testBasicSet(t, scenarioOptions{concurrency: 256})
		})
	})

	t.Run("cyclic", func(t *testing.T) {
		t.Run("no concurrency", func(t *testing.T) {
			testCyclicSet(t, scenarioOptions{})
		})

		t.Run("low concurrency", func(t *testing.T) {
			testCyclicSet(t, scenarioOptions{concurrency: 8})
		})

		t.Run("high concurrency", func(t *testing.T) {
			testCyclicSet(t, scenarioOptions{concurrency: 256})
		})
	})

	t.Run("nightshift", func(t *testing.T) {
		const (
			initial           = 15
			variation         = 10
			variationCycles   = 3
			variationStepTime = 10 * time.Millisecond
			dropStepTime      = time.Millisecond
			waitCycles        = 36
			waitTime          = time.Second
		)

		bus := syncbus.New(time.Second)
		clock := times.Test()
		o := pool.Options{
			Clock:   clock,
			TestBus: bus,
		}

		alloc := func() ([]byte, error) { return make([]byte, 1<<9), nil }
		p := pool.Make(alloc, nil, o)

		var active [][]byte
		get := func() {
			b, err := p.Get()
			if err != nil {
				t.Fatal(err)
			}

			active = append(active, b)
		}

		put := func() {
			if len(active) == 0 {
				t.Fatal("put called from empty active")
			}

			var b []byte
			b, active = active[0], active[1:]
			p.Put(b)
		}

		for i := 0; i < initial; i++ {
			get()
		}

		for i := 0; i <= variationCycles; i++ {
			for j := 0; j < variation; j++ {
				put()
				clock.Pass(variationStepTime)
			}

			for j := 0; j < variation; j++ {
				get()
				clock.Pass(variationStepTime)
			}
		}

		for len(active) > 0 {
			put()
			clock.Pass(dropStepTime)
		}

		for i := 0; i < waitCycles; i++ {
			if err := bus.Wait("background-job-waiting"); err != nil {
				t.Fatal(err)
			}

			bus.ResetSignals("background-job-waiting")
			clock.Pass(waitTime)
			if err := bus.Wait("free-idle-done"); err != nil {
				t.Fatal(err)
			}

			bus.ResetSignals("free-idle-done")
		}

		if p.Stats().Idle != 0 {
			t.Fatal(p.Stats())
		}
	})

	t.Run("external put", func(t *testing.T) {
		t.Run("initial", func(t *testing.T) {
			const (
				initialCount    = 15
				steadyUseCycles = 8
			)

			alloc := func() ([]byte, error) { return make([]byte, 1<<9), nil }
			p := pool.Make(alloc, nil, pool.Options{})

			var active [][]byte
			get := func() {
				b, err := p.Get()
				if err != nil {
					t.Fatal(err)
				}

				active = append(active, b)
			}

			put := func() {
				if len(active) == 0 {
					t.Fatal("put called from empty active")
				}

				var b []byte
				b, active = active[0], active[1:]
				p.Put(b)
			}

			for i := 0; i < initialCount; i++ {
				p.Put(make([]byte, 1<<9))
			}

			for i := 0; i < steadyUseCycles; i++ {
				get()
				put()
			}

			s := p.Stats()
			e := pool.Stats{Idle: 0, Active: 0, Get: 8, Put: 23, Alloc: 8, Free: 23}
			if s != e {
				t.Fatal(s)
			}
		})

		t.Run("expect higher load", func(t *testing.T) {
			const (
				initialCount    = 15
				steadyUseCycles = 8
				adjustCount     = 15
				highLoadCycles  = 8
			)

			alloc := func() ([]byte, error) { return make([]byte, 1<<9), nil }
			p := pool.Make(alloc, nil, pool.Options{})

			var active [][]byte
			get := func() {
				b, err := p.Get()
				if err != nil {
					t.Fatal(err)
				}

				active = append(active, b)
			}

			put := func() {
				if len(active) == 0 {
					t.Fatal("put called from empty active")
				}

				var b []byte
				b, active = active[0], active[1:]
				p.Put(b)
			}

			for i := 0; i < initialCount; i++ {
				get()
			}

			for i := 0; i < steadyUseCycles; i++ {
				get()
				put()
			}

			for i := 0; i < adjustCount; i++ {
				p.Put(make([]byte, 1<<9))
			}

			for i := 0; i < highLoadCycles; i++ {
				get()
				get()
				put()
			}

			s := p.Stats()
			e := pool.Stats{Idle: 1, Active: 8, Get: 39, Put: 31, Alloc: 20, Free: 11}
			if s != e {
				t.Fatal(s)
			}
		})
	})

	t.Run("load", func(t *testing.T) {
		t.Run("prewarm", func(t *testing.T) {
			const (
				initialCount    = 15
				steadyUseCycles = 8
			)

			alloc := func() ([]byte, error) { return make([]byte, 1<<9), nil }
			p := pool.Make(alloc, nil, pool.Options{})

			var active [][]byte
			get := func() {
				b, err := p.Get()
				if err != nil {
					t.Fatal(err)
				}

				active = append(active, b)
			}

			put := func() {
				if len(active) == 0 {
					t.Fatal("put called from empty active")
				}

				var b []byte
				b, active = active[0], active[1:]
				p.Put(b)
			}

			l := make([][]byte, initialCount)
			for i := 0; i < initialCount; i++ {
				l[i] = make([]byte, 1<<9)
			}

			p.Load(l)
			for i := 0; i < steadyUseCycles; i++ {
				get()
				put()
			}

			s := p.Stats()
			e := pool.Stats{Idle: 3, Active: 0, Get: 8, Put: 8, Alloc: 0, Load: initialCount, Free: 12}
			if s != e {
				t.Fatal(s)
			}
		})

		t.Run("expect higher load", func(t *testing.T) {
			const (
				initialCount    = 15
				steadyUseCycles = 8
				adjustCount     = 15
				highLoadCycles  = 8
			)

			alloc := func() ([]byte, error) { return make([]byte, 1<<9), nil }
			p := pool.Make(alloc, nil, pool.Options{})

			var active [][]byte
			get := func() {
				b, err := p.Get()
				if err != nil {
					t.Fatal(err)
				}

				active = append(active, b)
			}

			put := func() {
				if len(active) == 0 {
					t.Fatal("put called from empty active")
				}

				var b []byte
				b, active = active[0], active[1:]
				p.Put(b)
			}

			for i := 0; i < initialCount; i++ {
				get()
			}

			for i := 0; i < steadyUseCycles; i++ {
				get()
				put()
			}

			l := make([][]byte, adjustCount)
			for i := 0; i < adjustCount; i++ {
				l[i] = make([]byte, 1<<9)
			}

			p.Load(l)
			for i := 0; i < highLoadCycles; i++ {
				get()
				get()
				put()
			}

			s := p.Stats()
			e := pool.Stats{Idle: 8, Active: 23, Get: 39, Put: 16, Alloc: 16, Load: adjustCount, Free: 0}
			if s != e {
				t.Fatal(s)
			}
		})
	})
}