package agent_test

import (
	"os"
	"path/filepath"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"

	"github.com/coder/coder/v2/agent"
	"github.com/coder/coder/v2/agent/agentcontextconfig"
	"github.com/coder/coder/v2/agent/agenttest"
	agentproto "github.com/coder/coder/v2/agent/proto"
	"github.com/coder/coder/v2/codersdk/agentsdk"
	"github.com/coder/coder/v2/testutil"
)

// TestAgent_ContextStatePushed verifies the agent pushes its workspace
// context over the v2.10 PushContextState RPC, and that the readiness
// gate (SetReady, wired to the lifecycle transition) holds the push
// until startup completes. The first push therefore already contains
// the seeded AGENTS.md with Initial=true and no "unreadable" issues.
func TestAgent_ContextStatePushed(t *testing.T) {
	t.Parallel()

	dir := t.TempDir()
	require.NoError(t,
		os.WriteFile(filepath.Join(dir, "AGENTS.md"), []byte("test rules"), 0o600))

	//nolint:dogsled // setupAgent returns a wide tuple; we only care about the client.
	_, client, _, _, _ := setupAgent(t,
		agentsdk.Manifest{Directory: dir},
		0,
		func(_ *agenttest.Client, opts *agent.Options) {
			opts.ContextConfig = agentcontextconfig.Config{}
		},
	)

	// The push is gated until the agent reaches lifecycle ready. Wait
	// for that first push to land.
	var pushes []*agentproto.PushContextStateRequest
	require.Eventually(t, func() bool {
		pushes = client.ContextStatePushes()
		return len(pushes) > 0
	}, testutil.WaitMedium, testutil.IntervalFast,
		"expected a context snapshot push after startup; got %d pushes", len(pushes))

	first := pushes[0]
	assert.True(t, first.GetInitial(), "first push must carry Initial=true")
	assert.NotEmpty(t, first.GetAggregateHash(), "aggregate_hash must be populated")

	// The first push must already reflect the ready workspace: the
	// seeded AGENTS.md is present and no resource is UNREADABLE.
	var foundAgents bool
	for _, r := range first.GetResources() {
		if r.GetInstructionFile() != nil &&
			filepath.Base(r.GetSource()) == "AGENTS.md" {
			foundAgents = true
		}
		assert.NotEqualf(t, agentproto.ContextResource_UNREADABLE, r.GetStatus(),
			"no resource should be UNREADABLE in the post-ready snapshot: %s", r.GetSource())
	}
	assert.True(t, foundAgents, "first push must already include the seeded AGENTS.md")

	// Subsequent pushes must not be Initial.
	for _, p := range pushes[1:] {
		assert.False(t, p.GetInitial(), "only the first push must be Initial")
	}
}