package config

import (
	"strings"
	"testing"
)

// Why the assistant is off.
//
// "Off" was the same answer for four different mistakes, and the only symptom
// was a disabled composer. Nobody could tell "we have not switched it on" from
// "somebody misspelled a variable" — which is how it stayed off for days with
// both of us guessing.

func TestAFullyConfiguredAssistantIsOn(t *testing.T) {
	cfg := AssistantConfig{
		Provider: "openai", BaseURL: "https://api.groq.com/openai/v1",
		APIKey: "k", Balanced: "openai/gpt-oss-120b",
	}
	if !cfg.Enabled() {
		t.Fatalf("a complete config was refused: %s", cfg.Why())
	}
	if cfg.Why() != "" {
		t.Fatalf("an enabled assistant gave a reason: %q", cfg.Why())
	}
}

func TestEachMissingPieceNamesItself(t *testing.T) {
	for name, tc := range map[string]struct {
		cfg  AssistantConfig
		says string
	}{
		// Nothing set at all names the MODEL, not the provider. The provider is
		// derived from the model now, so an empty one is a consequence rather
		// than a cause — and sending an operator to set ASSISTANT_PROVIDER, a
		// variable they no longer need, while the one they actually missed goes
		// unmentioned, is the same "off for four reasons" problem in new words.
		"nothing set at all": {AssistantConfig{}, "ASSISTANT_MODEL"},
		"no provider": {
			AssistantConfig{Balanced: "m", APIKey: "k"}, "ASSISTANT_PROVIDER"},
		"unknown provider": {
			AssistantConfig{Provider: "anthropik", Balanced: "m", APIKey: "k"}, "not one this server speaks"},
		"no model":   {AssistantConfig{Provider: "openai", APIKey: "k"}, "ASSISTANT_MODEL"},
		"no api key": {AssistantConfig{Provider: "openai", Balanced: "m", BaseURL: "https://api.groq.com/openai/v1"}, "ASSISTANT_API_KEY"},
	} {
		why := tc.cfg.Why()
		if why == "" {
			t.Fatalf("%s: reported as working", name)
		}
		if !strings.Contains(why, tc.says) {
			t.Fatalf("%s: does not name the problem: %q", name, why)
		}
	}
}

func TestALocalModelNeedsNoKey(t *testing.T) {
	// Ollama and LM Studio need no credential, and demanding one would refuse
	// the setup a developer is most likely to have on their own machine.
	for _, base := range []string{
		"http://localhost:11434/v1",
		"http://127.0.0.1:1234/v1",
		"http://host.docker.internal:11434/v1",
	} {
		cfg := AssistantConfig{Provider: "openai", BaseURL: base, Balanced: "llama3"}
		if !cfg.Enabled() {
			t.Fatalf("%s was refused without a key: %s", base, cfg.Why())
		}
	}
}

func TestAHostedModelWithoutAKeyIsRefusedBeforeItFailsAtRuntime(t *testing.T) {
	// Otherwise the first question a shopkeeper asks comes back as a 401 from
	// the provider, which reads as the assistant being broken rather than as a
	// variable nobody set.
	cfg := AssistantConfig{Provider: "openai", BaseURL: "https://api.groq.com/openai/v1", Balanced: "m"}
	if cfg.Enabled() {
		t.Fatal("a hosted provider with no key reported as ready")
	}
}

func TestTheTierFallbackDoesNotHideAMissingModel(t *testing.T) {
	// `fast` and `deep` fall back to balanced, so a config with only those two
	// set has no model at all for the default tier.
	cfg := AssistantConfig{Provider: "openai", APIKey: "k", Fast: "small", Deep: "big"}
	if cfg.Enabled() {
		t.Fatal("an assistant with no balanced model reported as ready")
	}
	if cfg.ModelFor("fast") != "" && cfg.ModelFor("balanced") != "" {
		t.Fatal("balanced resolved to something despite being unset")
	}
}

// Where a secret is allowed to live.
//
// `.env`, `.env.local` and `.env.production` are all tracked by git, so a key
// written to any of them is a key published. There was nowhere else, and the
// standing instruction was to export it in the shell on every run — which is
// the kind of instruction people route around by editing a tracked file.
func TestASecretsFileIsReadBeforeAnyTrackedEnvFile(t *testing.T) {
	order := envFileOrder("local")

	if len(order) == 0 || order[0] != ".env.secrets" {
		t.Fatalf(".env.secrets is not read first, so a tracked file wins: %v", order)
	}
	// godotenv does not overwrite, so being first IS what makes it authoritative.
	// Being merely present would let .env.local decide the key instead.
	for _, tracked := range []string{".env.local", ".env"} {
		for i, name := range order {
			if name == tracked && i == 0 {
				t.Fatalf("%s is read first; a secret there would be committed", tracked)
			}
		}
	}
}

func TestTheEnvironmentsOwnFileBeatsTheSharedOne(t *testing.T) {
	// `.env.production` must be consulted before the shared `.env`, or a
	// production deployment silently takes the local defaults.
	order := envFileOrder("production")

	var production, shared int = -1, -1
	for i, name := range order {
		switch name {
		case ".env.production":
			production = i
		case ".env":
			shared = i
		}
	}
	if production < 0 || shared < 0 || production > shared {
		t.Fatalf("the environment's own file does not take precedence: %v", order)
	}
}

// One variable, not four.
//
// The assistant sat switched off for days because `ASSISTANT_PROVIDER` had not
// been typed into a hosting platform's environment tab — a variable whose only
// correct value is "openai", because every endpoint this server speaks is
// OpenAI-compatible. The base URL and the model had one right answer too.
//
// So three of the four are constants now. The key is the only one that varies
// between deployments and the only one that cannot live in the repository.
func TestTheKeyAloneSwitchesTheAssistantOn(t *testing.T) {
	for _, name := range []string{
		"ASSISTANT_PROVIDER", "ASSISTANT_BASE_URL", "ASSISTANT_MODEL",
		"ASSISTANT_MODEL_BALANCED", "ASSISTANT_MODEL_FAST", "ASSISTANT_MODEL_DEEP",
	} {
		t.Setenv(name, "")
	}
	t.Setenv("ASSISTANT_API_KEY", "gsk_not-a-real-key")

	cfg := AssistantConfig{
		Provider: assistantProvider(),
		BaseURL:  env("ASSISTANT_BASE_URL", defaultAssistantBaseURL),
		APIKey:   env("ASSISTANT_API_KEY", ""),
		Balanced: env("ASSISTANT_MODEL_BALANCED", env("ASSISTANT_MODEL", defaultAssistantModel)),
	}

	if !cfg.Enabled() {
		t.Fatalf("the key alone did not switch it on: %s", cfg.Why())
	}
	if cfg.Provider != "openai" {
		t.Fatalf("provider defaulted to %q", cfg.Provider)
	}
	if cfg.ModelFor("fast") != defaultAssistantModel {
		t.Fatalf("the fast tier fell through to %q", cfg.ModelFor("fast"))
	}
}

func TestNoKeyIsStillOffAndSaysWhich(t *testing.T) {
	// The defaults must not make an unconfigured deployment look ready. Without
	// a key every question would reach Groq and come back 401, which reads as
	// the assistant being broken rather than as not being set up.
	cfg := AssistantConfig{
		Provider: defaultAssistantProvider,
		BaseURL:  defaultAssistantBaseURL,
		Balanced: defaultAssistantModel,
	}
	if cfg.Enabled() {
		t.Fatal("reported ready with no key")
	}
	if !strings.Contains(cfg.Why(), "ASSISTANT_API_KEY") {
		t.Fatalf("did not name the one variable left to set: %q", cfg.Why())
	}
}

func TestEachDefaultIsStillOverridable(t *testing.T) {
	// Running against Ollama on a laptop must not need a code change.
	t.Setenv("ASSISTANT_PROVIDER", "ollama")
	t.Setenv("ASSISTANT_BASE_URL", "http://localhost:11434/v1")
	t.Setenv("ASSISTANT_MODEL", "llama3")

	cfg := AssistantConfig{
		Provider: assistantProvider(),
		BaseURL:  env("ASSISTANT_BASE_URL", defaultAssistantBaseURL),
		APIKey:   env("ASSISTANT_API_KEY", ""),
		Balanced: env("ASSISTANT_MODEL_BALANCED", env("ASSISTANT_MODEL", defaultAssistantModel)),
	}

	if cfg.Provider != "ollama" || cfg.Balanced != "llama3" {
		t.Fatalf("an override was ignored: %+v", cfg)
	}
	// Local endpoints need no key, so this must be on without one.
	if !cfg.Enabled() {
		t.Fatalf("a local model was refused: %s", cfg.Why())
	}
}