package backthink

import (
	"context"
	"testing"
	"time"

	"git.yeij.top/AskaEth/Cyrene_v2/internal/channel/adapter"
)

func TestPusher_ActiveFirst(t *testing.T) {
	t.Parallel()
	active := &mockActive{n: 2}
	im := &mockIMAdapter{}
	p := newPusher(active, im, &mockGate{allow: true}, discardLog())

	res := p.Push(context.Background(), PushRequest{Message: adapter.UnifiedMessage{}})

	if !res.Pushed {
		t.Fatalf("Pushed = false, want true")
	}
	if res.Route != RouteActiveClient {
		t.Fatalf("Route = %q, want %q", res.Route, RouteActiveClient)
	}
	if active.calls != 1 {
		t.Fatalf("active calls = %d, want 1", active.calls)
	}
	if im.count() != 0 {
		t.Fatalf("im calls = %d, want 0 (active should be preferred)", im.count())
	}
}

func TestPusher_IMFallback_NoActive(t *testing.T) {
	t.Parallel()
	active := &mockActive{n: 0} // no active client online
	im := &mockIMAdapter{}
	p := newPusher(active, im, &mockGate{allow: true}, discardLog())

	res := p.Push(context.Background(), PushRequest{Message: adapter.UnifiedMessage{}})

	if !res.Pushed {
		t.Fatalf("Pushed = false, want true")
	}
	if res.Route != RouteIMBridge {
		t.Fatalf("Route = %q, want %q", res.Route, RouteIMBridge)
	}
	if im.count() != 1 {
		t.Fatalf("im calls = %d, want 1", im.count())
	}
}

func TestPusher_IMFallback_ActiveError(t *testing.T) {
	t.Parallel()
	active := &mockActive{err: context.DeadlineExceeded}
	im := &mockIMAdapter{}
	p := newPusher(active, im, &mockGate{allow: true}, discardLog())

	res := p.Push(context.Background(), PushRequest{Message: adapter.UnifiedMessage{}})

	if !res.Pushed {
		t.Fatalf("Pushed = false, want true")
	}
	if res.Route != RouteIMBridge {
		t.Fatalf("Route = %q, want %q", res.Route, RouteIMBridge)
	}
	if im.count() != 1 {
		t.Fatalf("im calls = %d, want 1", im.count())
	}
}

func TestPusher_NoTarget_Skipped(t *testing.T) {
	t.Parallel()
	p := newPusher(nil, nil, &mockGate{allow: true}, discardLog())

	res := p.Push(context.Background(), PushRequest{Message: adapter.UnifiedMessage{}})

	if res.Pushed {
		t.Fatalf("Pushed = true, want false")
	}
	if res.Route != RouteNone {
		t.Fatalf("Route = %q, want %q", res.Route, RouteNone)
	}
}

func TestPusher_GateDenied(t *testing.T) {
	t.Parallel()
	active := &mockActive{n: 1}
	im := &mockIMAdapter{}
	p := newPusher(active, im, &mockGate{allow: false}, discardLog())

	res := p.Push(context.Background(), PushRequest{Message: adapter.UnifiedMessage{}})

	if res.Pushed {
		t.Fatalf("Pushed = true, want false")
	}
	if res.Route != RouteRateLimited {
		t.Fatalf("Route = %q, want %q", res.Route, RouteRateLimited)
	}
	if active.calls != 0 || im.count() != 0 {
		t.Fatalf("targets called despite denial: active=%d im=%d", active.calls, im.count())
	}
}

func TestPusher_CancelledContext_Denied(t *testing.T) {
	t.Parallel()
	active := &mockActive{n: 1}
	p := newPusher(active, nil, &mockGate{allow: true}, discardLog())
	ctx, cancel := context.WithCancel(context.Background())
	cancel()

	res := p.Push(ctx, PushRequest{Message: adapter.UnifiedMessage{}})

	if res.Pushed {
		t.Fatalf("Pushed = true, want false")
	}
	if res.Route != RouteNone {
		t.Fatalf("Route = %q, want %q", res.Route, RouteNone)
	}
	if active.calls != 0 {
		t.Fatalf("active calls = %d, want 0", active.calls)
	}
}

// TestPusher_RateLimit exercises the production rateGate over session.RateLimiter:
// with a limit of 1 push per window, only the first of three attempts passes.
func TestPusher_RateLimit(t *testing.T) {
	t.Parallel()
	active := &mockActive{n: 1}
	p := newPusher(active, nil, newRateGate(1, time.Minute, discardLog()), discardLog())

	first := p.Push(context.Background(), PushRequest{Message: adapter.UnifiedMessage{}})
	second := p.Push(context.Background(), PushRequest{Message: adapter.UnifiedMessage{}})
	third := p.Push(context.Background(), PushRequest{Message: adapter.UnifiedMessage{}})

	if !first.Pushed || first.Route != RouteActiveClient {
		t.Fatalf("first push = %+v, want active_client pushed", first)
	}
	if second.Pushed || second.Route != RouteRateLimited {
		t.Fatalf("second push = %+v, want rate_limited not pushed", second)
	}
	if third.Pushed || third.Route != RouteRateLimited {
		t.Fatalf("third push = %+v, want rate_limited not pushed", third)
	}
	if active.calls != 1 {
		t.Fatalf("active calls = %d, want 1 (rate limit caps the sink)", active.calls)
	}
}