package pool_test

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

var errTest = errors.New("test error")

func TestPool(t *testing.T) {
	t.Run("initial stats", func(t *testing.T) {
		alloc := func() ([]byte, error) { return make([]byte, 1<<9), nil }
		p := pool.Make(alloc, nil, pool.Options{Algo: pool.NoShrink()})
		s := p.Stats()
		e := pool.Stats{}
		if s != e {
			t.Fatal(s)
		}
	})

	t.Run("get when empty", func(t *testing.T) {
		alloc := func() ([]byte, error) { return make([]byte, 1<<9), nil }
		p := pool.Make(alloc, nil, pool.Options{Algo: pool.NoShrink()})
		b, err := p.Get()
		if err != nil {
			t.Fatal(err)
		}

		if len(b) != 1<<9 {
			t.Fatal(len(b))
		}

		s := p.Stats()
		e := pool.Stats{Alloc: 1, Get: 1, Active: 1}
		if s != e {
			t.Fatal(s)
		}
	})

	t.Run("get pooled own", func(t *testing.T) {
		alloc := func() ([]byte, error) { return make([]byte, 1<<9), nil }
		p := pool.Make(alloc, nil, pool.Options{Algo: pool.NoShrink()})
		b, err := p.Get()
		if err != nil {
			t.Fatal(err)
		}

		if len(b) != 1<<9 {
			t.Fatal(len(b))
		}

		p.Put(b)
		b, err = p.Get()
		if err != nil {
			t.Fatal(err)
		}

		if len(b) != 1<<9 {
			t.Fatal(len(b))
		}

		s := p.Stats()
		e := pool.Stats{Alloc: 1, Get: 2, Put: 1, Active: 1}
		if s != e {
			t.Fatal(s)
		}
	})

	t.Run("get pooled foreign", func(t *testing.T) {
		alloc := func() ([]byte, error) { return make([]byte, 1<<9), nil }
		p := pool.Make(alloc, nil, pool.Options{Algo: pool.NoShrink()})
		p.Put(make([]byte, 1<<6))
		b, err := p.Get()
		if err != nil {
			t.Fatal(err)
		}

		if len(b) != 1<<6 {
			t.Fatal(len(b))
		}

		s := p.Stats()
		e := pool.Stats{Get: 1, Put: 1, Active: 1}
		if s != e {
			t.Fatal(s)
		}
	})

	t.Run("get own alloc not available", func(t *testing.T) {
		p := pool.Make[[]byte](nil, nil, pool.Options{Algo: pool.NoShrink()})
		_, err := p.Get()
		if !errors.Is(err, pool.ErrEmpty) {
			t.Fatal(err)
		}

		s := p.Stats()
		e := pool.Stats{Alloc: 1, Get: 1}
		if s != e {
			t.Fatal(s)
		}
	})

	t.Run("get foreign no alloc", func(t *testing.T) {
		p := pool.Make[[]byte](nil, nil, pool.Options{Algo: pool.NoShrink()})
		p.Put(make([]byte, 1<<6))
		b, err := p.Get()
		if err != nil {
			t.Fatal(err)
		}

		if len(b) != 1<<6 {
			t.Fatal(len(b))
		}

		s := p.Stats()
		e := pool.Stats{Get: 1, Put: 1, Active: 1}
		if s != e {
			t.Fatal(s)
		}
	})

	t.Run("allocation error", func(t *testing.T) {
		alloc := func() ([]byte, error) { return nil, errTest }
		p := pool.Make(alloc, nil, pool.Options{Algo: pool.NoShrink()})
		_, err := p.Get()
		if !errors.Is(err, errTest) {
			t.Fatal(err)
		}
	})

	t.Run("put foreign not empty", func(t *testing.T) {
		p := pool.Make[[]byte](nil, nil, pool.Options{Algo: pool.NoShrink()})
		p.Put(make([]byte, 1<<6))
		p.Put(make([]byte, 1<<6))
		b, err := p.Get()
		if err != nil {
			t.Fatal(err)
		}

		if len(b) != 1<<6 {
			t.Fatal(len(b))
		}

		s := p.Stats()
		e := pool.Stats{Get: 1, Put: 2, Active: 1, Idle: 1}
		if s != e {
			t.Fatal(s)
		}
	})

	t.Run("load items", func(t *testing.T) {
		p := pool.Make[[]byte](nil, nil, pool.Options{Algo: pool.NoShrink()})
		l := make([][]byte, 9)
		for i := 0; i < len(l); i++ {
			l[i] = make([]byte, 1<<9)
		}

		p.Load(l)
		s := p.Stats()
		if s.Idle != 9 {
			t.Fatal(s)
		}
	})

	t.Run("release on put no free", func(t *testing.T) {
		p := pool.Make[[]byte](nil, nil, pool.Options{Algo: pool.Max(2)})
		p.Put(make([]byte, 1<<9))
		p.Put(make([]byte, 1<<9))
		p.Put(make([]byte, 1<<9))
		s := p.Stats()
		e := pool.Stats{Put: 3, Idle: 2, Free: 1}
		if s != e {
			t.Fatal(s)
		}
	})

	t.Run("release on put with free", func(t *testing.T) {
		var freeCount int
		f := func([]byte) { freeCount++ }
		p := pool.Make(nil, f, pool.Options{Algo: pool.Max(2)})
		p.Put(make([]byte, 1<<9))
		p.Put(make([]byte, 1<<9))
		p.Put(make([]byte, 1<<9))
		if freeCount != 1 {
			t.Fatal(freeCount)
		}

		s := p.Stats()
		e := pool.Stats{Put: 3, Idle: 2, Free: 1}
		if s != e {
			t.Fatal(s)
		}
	})

	t.Run("release all no free", func(t *testing.T) {
		p := pool.Make[[]byte](nil, nil, pool.Options{Algo: pool.NoShrink()})
		p.Put(make([]byte, 1<<9))
		p.Put(make([]byte, 1<<9))
		p.Put(make([]byte, 1<<9))
		p.Free()
		s := p.Stats()
		e := pool.Stats{Put: 3, Idle: 0, Free: 3}
		if s != e {
			t.Fatal(s)
		}
	})

	t.Run("release all with free", func(t *testing.T) {
		var freeCount int
		f := func([]byte) { freeCount++ }
		p := pool.Make[[]byte](nil, f, pool.Options{Algo: pool.NoShrink()})
		p.Put(make([]byte, 1<<9))
		p.Put(make([]byte, 1<<9))
		p.Put(make([]byte, 1<<9))
		p.Free()
		if freeCount != 3 {
			t.Fatal(freeCount)
		}

		s := p.Stats()
		e := pool.Stats{Put: 3, Idle: 0, Free: 3}
		if s != e {
			t.Fatal(s)
		}
	})

	t.Run("release all when empty", func(t *testing.T) {
		p := pool.Make[[]byte](nil, nil, pool.Options{Algo: pool.NoShrink()})
		p.Free()
		s := p.Stats()

		var e pool.Stats
		if s != e {
			t.Fatal(s)
		}
	})

	t.Run("release on timeout no free", func(t *testing.T) {
		c := times.Test()
		b := syncbus.New(time.Second)
		o := pool.Options{
			Algo:    pool.Timeout(3 * time.Millisecond),
			Clock:   c,
			TestBus: b,
		}

		p := pool.Make[[]byte](nil, nil, o)
		p.Put(make([]byte, 1<<9))
		if err := b.Wait("background-job-waiting"); err != nil {
			t.Fatal(err)
		}

		c.Pass(2 * time.Millisecond)
		p.Put(make([]byte, 1<<9))
		c.Pass(2 * time.Millisecond)
		if err := b.Wait("free-idle-done"); err != nil {
			t.Fatal(err)
		}

		s := p.Stats()
		e := pool.Stats{Put: 2, Idle: 1, Free: 1}
		if s != e {
			t.Fatal(s)
		}
	})

	t.Run("release on timeout with free", func(t *testing.T) {
		var freeCount int
		f := func([]byte) { freeCount++ }
		c := times.Test()
		b := syncbus.New(time.Second)
		o := pool.Options{
			Algo:    pool.Timeout(3 * time.Millisecond),
			Clock:   c,
			TestBus: b,
		}

		p := pool.Make[[]byte](nil, f, o)
		p.Put(make([]byte, 1<<9))
		if err := b.Wait("background-job-waiting"); err != nil {
			t.Fatal(err)
		}

		c.Pass(2 * time.Millisecond)
		p.Put(make([]byte, 1<<9))
		c.Pass(2 * time.Millisecond)
		if err := b.Wait("free-idle-done"); err != nil {
			t.Fatal(err)
		}

		s := p.Stats()
		e := pool.Stats{Put: 2, Idle: 1, Free: 1}
		if s != e || freeCount != 1 {
			t.Fatal(s, freeCount)
		}
	})

	t.Run("use default algo", func(t *testing.T) {
		alloc := func() ([]byte, error) { return make([]byte, 1<<9), nil }
		p := pool.Make(alloc, nil, pool.Options{})

		var bs [][]byte
		for i := 0; i < 9; i++ {
			b, err := p.Get()
			if err != nil {
				t.Fatal(err)
			}

			bs = append(bs, b)
		}

		for _, b := range bs[:2*len(bs)/3] {
			p.Put(b)
		}

		s := p.Stats()
		e := pool.Stats{Alloc: 9, Get: 9, Put: 6, Active: 3, Idle: 6, Free: 0}
		if s != e {
			t.Fatal(s)
		}
	})
}