package service

import (
	"context"
	"errors"
	"io"
	"strings"
	"testing"

	"github.com/aritmolab/thothii/tools/tht/internal/compose"
	"github.com/aritmolab/thothii/tools/tht/internal/config"
)

// Catches --build being ignored, which would run stale images after a checkout update.
func TestStartBuildsBeforeStartingAndCheckingHealth(t *testing.T) {
	stubModelProjection(t, nil)
	runner := &recordingRunner{}
	installation := testInstallation()

	if err := Start(context.Background(), installation, runner, true); err != nil {
		t.Fatal(err)
	}
	if got, want := strings.Join(runner.stages, " -> "), "build -> up -> health"; got != want {
		t.Fatalf("Start(..., build=true) stages = %q, want %q", got, want)
	}
}

// Catches a normal start unnecessarily rebuilding images.
func TestStartSkipsBuildUnlessRequested(t *testing.T) {
	stubModelProjection(t, nil)
	runner := &recordingRunner{}
	installation := testInstallation()

	if err := Start(context.Background(), installation, runner, false); err != nil {
		t.Fatal(err)
	}
	if got, want := strings.Join(runner.stages, " -> "), "up -> health"; got != want {
		t.Fatalf("Start(..., build=false) stages = %q, want %q", got, want)
	}
}

func TestStartRefusesProjectedAuthenticationBeforeComposeWhenNotReady(t *testing.T) {
	stubModelProjection(t, nil)
	for _, state := range []string{"missing", "blocked", "divergent"} {
		t.Run(state, func(t *testing.T) {
			previous := requireRuntimeAuthProjectionReady
			requireRuntimeAuthProjectionReady = func(installation config.Installation) error {
				if !installation.HasRuntimeAuthProjection() {
					t.Fatal("readiness gate received an unprojected installation")
				}
				return errors.New("synthetic " + state + " projection")
			}
			t.Cleanup(func() { requireRuntimeAuthProjectionReady = previous })

			runner := &recordingRunner{}
			err := Start(context.Background(), projectedTestInstallation(), runner, true)
			if err == nil {
				t.Fatalf("Start() accepted %s runtime projection", state)
			}
			if len(runner.stages) != 0 {
				t.Fatalf("Start() reached Compose for %s projection: %v", state, runner.stages)
			}
		})
	}
}

func TestStartRefusesProjectionFailureBeforeCompose(t *testing.T) {
	stubModelProjection(t, errors.New("synthetic projection failure"))
	runner := &recordingRunner{}

	err := Start(context.Background(), testInstallation(), runner, false)
	if err == nil || !strings.Contains(err.Error(), "model runtime projection") {
		t.Fatalf("Start() error = %v", err)
	}
	if len(runner.stages) != 0 {
		t.Fatalf("Start() reached Compose: %v", runner.stages)
	}
}

func stubModelProjection(t *testing.T, result error) {
	t.Helper()
	previous := generateModelProjections
	generateModelProjections = func(config.Installation) error { return result }
	t.Cleanup(func() { generateModelProjections = previous })
}

type recordingRunner struct{ stages []string }

func (r *recordingRunner) Run(_ context.Context, args []string, _ io.Reader) (compose.Result, error) {
	joined := strings.Join(args, " ")
	switch {
	case strings.HasSuffix(joined, " build"):
		r.stages = append(r.stages, "build")
	case strings.HasSuffix(joined, " up --detach --remove-orphans"):
		r.stages = append(r.stages, "up")
	case strings.HasSuffix(joined, " ps --all --format json"):
		r.stages = append(r.stages, "health")
		return compose.Result{Stdout: healthyServices}, nil
	}
	return compose.Result{}, nil
}

func testInstallation() config.Installation {
	return config.Installation{
		Path:             "/tmp/thothii/deploy/local/thothii-installation.yaml",
		Profile:          "local",
		ProjectDirectory: "/tmp/thothii",
		EnvFile:          "/tmp/thothii/deploy/local/operator.env",
	}
}

func projectedTestInstallation() config.Installation {
	installation := testInstallation()
	installation.Profile = "server"
	installation.Authentication.RuntimeProjection = &config.RuntimeProjection{
		Directory: "/runtime-auth", UID: 10001, GID: 10001,
	}
	return installation
}

const healthyServices = `[
  {"Service":"core","State":"running","Health":"healthy"},
  {"Service":"frontend","State":"running","Health":"healthy"},
  {"Service":"qdrant","State":"running","Health":"healthy"},
  {"Service":"embedding","State":"running","Health":"healthy"},
  {"Service":"embedding-model-init","State":"exited","ExitCode":0}
]`