package deploy

import (
	"os"
	"slices"
	"strings"
	"testing"

	"go.yaml.in/yaml/v4"
)

type composeDocument struct {
	Services map[string]composeService `yaml:"services"`
	Volumes  map[string]any            `yaml:"volumes"`
}

type composeService struct {
	Image     string   `yaml:"image"`
	Command   []string `yaml:"command"`
	Ports     []string `yaml:"ports"`
	Volumes   []string `yaml:"volumes"`
	Tmpfs     []string `yaml:"tmpfs"`
	DependsOn any      `yaml:"depends_on"`
}

func TestPostgresIntegrationFixtureIsIsolatedAndEphemeral(t *testing.T) {
	document := loadComposeFile(t, "docker-compose.test.yml")
	postgres, ok := document.Services["postgres"]
	if !ok {
		t.Fatal("docker-compose.test.yml has no postgres service")
	}
	if postgres.Image != "postgres:18-alpine" {
		t.Fatalf("postgres image = %q, want postgres:18-alpine", postgres.Image)
	}
	if !slices.Equal(postgres.Ports, []string{"127.0.0.1:15432:5432"}) {
		t.Fatalf("postgres ports = %v, want loopback test port", postgres.Ports)
	}
	if !slices.Contains(postgres.Tmpfs, "/var/lib/postgresql") || len(postgres.Volumes) != 0 {
		t.Fatalf("postgres tmpfs = %v, volumes = %v; want ephemeral PG18 data root", postgres.Tmpfs, postgres.Volumes)
	}
}

func TestRedisFixtureScriptUsesDedicatedComposeProject(t *testing.T) {
	payload, err := os.ReadFile("../scripts/test-redis.ps1")
	if err != nil {
		t.Fatalf("read test-redis.ps1: %v", err)
	}
	script := string(payload)
	for _, required := range []string{
		`-p $composeProject`,
		`up -d --wait --wait-timeout 60 redis`,
		`down --volumes --remove-orphans`,
	} {
		if !strings.Contains(script, required) {
			t.Errorf("test-redis.ps1 missing %q", required)
		}
	}
}

func TestPostgresFixtureScriptUsesDedicatedComposeProject(t *testing.T) {
	payload, err := os.ReadFile("../scripts/test-postgres.ps1")
	if err != nil {
		t.Fatalf("read test-postgres.ps1: %v", err)
	}
	script := string(payload)
	for _, required := range []string{
		`-p $composeProject`,
		`up -d --wait --wait-timeout 60 postgres`,
		`PROXY_POOL_TEST_POSTGRES_URL`,
		`go test -count=1 -tags=integration -timeout 60s ./internal/adapters/postgresadmin/...`,
		`down --volumes --remove-orphans`,
	} {
		if !strings.Contains(script, required) {
			t.Errorf("test-postgres.ps1 missing %q", required)
		}
	}
}

func TestControllerFixtureScriptStartsBothStoresInDedicatedProject(t *testing.T) {
	payload, err := os.ReadFile("../scripts/test-controller.ps1")
	if err != nil {
		t.Fatalf("read test-controller.ps1: %v", err)
	}
	script := string(payload)
	for _, required := range []string{
		`-p $composeProject`,
		`up -d --wait --wait-timeout 60 postgres redis`,
		`PROXY_POOL_TEST_POSTGRES_URL`,
		`PROXY_POOL_TEST_REDIS_URL`,
		`go test -count=1 -tags=integration -timeout 60s ./internal/controller/bootstrap`,
		`down --volumes --remove-orphans`,
	} {
		if !strings.Contains(script, required) {
			t.Errorf("test-controller.ps1 missing %q", required)
		}
	}
}

func TestLocalRedisIsExplicitlyEphemeral(t *testing.T) {
	document := loadComposeDocument(t)
	redis, ok := document.Services["redis"]
	if !ok {
		t.Fatal("docker-compose.yml has no redis service")
	}
	if value, ok := commandFlag(redis.Command, "--appendonly"); !ok || value != "no" {
		t.Fatalf("redis --appendonly = %q, %t; want no", value, ok)
	}
	if value, ok := commandFlag(redis.Command, "--save"); !ok || value != "" {
		t.Fatalf("redis --save = %q, %t; want empty schedule", value, ok)
	}
	if len(redis.Volumes) != 0 {
		t.Fatalf("redis volumes = %v; want no persistent mount", redis.Volumes)
	}
	if _, exists := document.Volumes["redis-data"]; exists {
		t.Fatal("docker-compose.yml still declares redis-data")
	}
}

func TestLocalGatewaysDoNotDependOnControlPlaneStorage(t *testing.T) {
	document := loadComposeDocument(t)
	for _, name := range []string{"gateway-a", "gateway-b"} {
		gateway, ok := document.Services[name]
		if !ok {
			t.Fatalf("docker-compose.yml has no %s service", name)
		}
		for _, storage := range []string{"postgres", "redis"} {
			if composeDependsOn(gateway.DependsOn, storage) {
				t.Errorf("%s depends on %s; gateway startup must be storage-independent", name, storage)
			}
		}
	}
}

func loadComposeDocument(t *testing.T) composeDocument {
	t.Helper()
	return loadComposeFile(t, "docker-compose.yml")
}

func loadComposeFile(t *testing.T, name string) composeDocument {
	t.Helper()
	payload, err := os.ReadFile(name)
	if err != nil {
		t.Fatalf("read %s: %v", name, err)
	}
	var document composeDocument
	if err := yaml.Unmarshal(payload, &document); err != nil {
		t.Fatalf("parse %s: %v", name, err)
	}
	return document
}

func composeDependsOn(value any, service string) bool {
	switch dependencies := value.(type) {
	case map[string]any:
		_, exists := dependencies[service]
		return exists
	case []any:
		for _, dependency := range dependencies {
			if dependency == service {
				return true
			}
		}
	}
	return false
}

func commandFlag(command []string, name string) (string, bool) {
	for index := 0; index+1 < len(command); index++ {
		if command[index] == name {
			return command[index+1], true
		}
	}
	return "", false
}