package main

import "testing"

func TestAdaptiveSizerRecoversFromMinimum(t *testing.T) {
	opts := chunkClientOptions{
		startSize:      64,
		minSize:        32,
		maxSize:        1024,
		adaptive:       true,
		adaptSuccesses: 2,
	}
	s := newAdaptiveSizer("test", 64, opts)
	_, next := s.Failure(64)
	if next != 32 {
		t.Fatalf("failure should reduce 64 -> 32, got %d", next)
	}
	for i := 0; i < 16; i++ {
		s.Success(32)
	}
	if got := s.Current(); got <= 32 {
		t.Fatalf("adaptive controller remained stuck at minimum: %d", got)
	}
}

func newTestConn(min, max int) *chunkConn {
	return &chunkConn{pipeline: max, minPipeline: min, maxPipeline: max}
}

func TestPinnedBatchNeverAdapts(t *testing.T) {
	c := newTestConn(5, 5)
	if got := c.batchCount(1400); got != 5 {
		t.Fatalf("pinned batch should request 5 records, got %d", got)
	}
	for i := 0; i < 10; i++ {
		if _, _, shrank := c.shrinkPipeline(); shrank {
			t.Fatal("pinned batch shrank on transport failure")
		}
		c.growPipeline()
	}
	if c.pipeline != 5 {
		t.Fatalf("pinned batch drifted to %d", c.pipeline)
	}
	if got := c.batchCount(1400); got != 5 {
		t.Fatalf("pinned batch should still request 5 records, got %d", got)
	}
}

func TestPinnedBatchSurvivesOneMiBCap(t *testing.T) {
	// 8 x 1 MiB records exceed the ~1 MiB useful-data cap. A pinned depth must
	// win anyway, otherwise a path that needs exactly 8 records is broken by
	// an unrelated size heuristic.
	c := newTestConn(8, 8)
	if got := c.batchCount(1024 * 1024); got != 8 {
		t.Fatalf("pinned batch should ignore the 1 MiB cap, got %d", got)
	}
	// An unpinned batch is still capped.
	c = newTestConn(1, 8)
	if got := c.batchCount(1024 * 1024); got != 1 {
		t.Fatalf("unpinned batch should be capped to 1, got %d", got)
	}
}

func TestAdaptiveBatchStopsAtFloor(t *testing.T) {
	c := newTestConn(4, 32)
	seen := map[int]bool{}
	for i := 0; i < 12; i++ {
		_, next, _ := c.shrinkPipeline()
		seen[next] = true
	}
	if c.pipeline != 4 {
		t.Fatalf("batch fell to %d, want the floor 4", c.pipeline)
	}
	if !seen[16] || !seen[8] {
		t.Fatalf("expected halving through 16 and 8, saw %v", seen)
	}
	for i := 0; i < 100; i++ {
		c.growPipeline()
	}
	if c.pipeline != 32 {
		t.Fatalf("batch grew to %d, want the ceiling 32", c.pipeline)
	}
}

func TestSingleBatchIsFixed(t *testing.T) {
	c := newTestConn(1, 1)
	if !c.pinnedBatch() {
		t.Fatal("a 1..1 batch must be treated as pinned")
	}
	c.growPipeline()
	if c.pipeline != 1 {
		t.Fatalf("batch of 1 grew to %d", c.pipeline)
	}
}

func TestReconnectZeroMeansPersistent(t *testing.T) {
	lane := newRequestLane("127.0.0.1:1", 0, 0, 0)
	if lane.reconnectEvery != 0 {
		t.Fatalf("reconnectEvery=%d, want 0", lane.reconnectEvery)
	}
}