package config

import (
	"os"
	"path/filepath"

	"testing"
	"time"
)

func TestDefaultsAndOverrides(t *testing.T) {
	c, err := Load()
	if err != nil {
		t.Fatal(err)
	}
	if c.Addr != "127.0.0.1:8080" {
		t.Fatalf("default addr = %q; a control plane must not bind the world by default", c.Addr)
	}
	if c.Migrate {
		t.Fatal("migrations must be opt-in")
	}

	t.Setenv("TM_PLATFORM_ADDR", ":9000")
	t.Setenv("TM_PLATFORM_SESSION_IDLE", "30m")
	t.Setenv("TM_PLATFORM_TRUSTED_ORIGINS", "https://app.example.org, https://desktop.example.org ")
	c, err = Load()
	if err != nil {
		t.Fatal(err)
	}
	if c.Addr != ":9000" || c.SessionIdleTTL != 30*time.Minute {
		t.Fatalf("config = %+v", c)
	}
	if len(c.TrustedOrigins) != 2 || c.TrustedOrigins[1] != "https://desktop.example.org" {
		t.Fatalf("origins = %q", c.TrustedOrigins)
	}
}

// A RELATIVE state directory names two different directories: the exit marker is written by a unit
// whose WorkingDirectory is the BOOK's directory and read by this daemon from its own. The run then
// ends, its marker lands where nothing looks, and the reconciler restarts the run forever.
func TestARelativeStateDirectoryIsRefusedAtBoot(t *testing.T) {
	t.Setenv("TM_PLATFORM_STATE_DIR", "var/run-state")
	if _, err := Load(); err == nil {
		t.Fatal("a relative state directory was accepted; the marker it writes is unreadable by the daemon")
	}
	t.Setenv("TM_PLATFORM_STATE_DIR", "/var/lib/other")
	c, err := Load()
	if err != nil {
		t.Fatal(err)
	}
	if c.Runner.StateDir != "/var/lib/other" {
		t.Errorf("state dir = %q", c.Runner.StateDir)
	}
}

// The engine's ceiling flag landed (row 145, D39.122), so its form is the default rather than one
// more thing an operator must set before any run can start. An override that cannot carry the amount
// is refused instead of being sent as a literal.
func TestTheCeilingArgumentHasTheLandedFormByDefault(t *testing.T) {
	c, err := Load()
	if err != nil {
		t.Fatal(err)
	}
	if c.Runner.CeilingArg != "--ceiling-usd {{usd}}" {
		t.Errorf("default ceiling argument = %q", c.Runner.CeilingArg)
	}
}

func TestImpossibleSessionWindowIsRefusedAtBoot(t *testing.T) {
	t.Setenv("TM_PLATFORM_SESSION_IDLE", "100h")
	t.Setenv("TM_PLATFORM_SESSION_MAX_AGE", "1h")
	if _, err := Load(); err == nil {
		t.Fatal("an idle window longer than the absolute one must fail at boot, not at 3am")
	}
}

func TestMalformedDurationIsRefused(t *testing.T) {
	t.Setenv("TM_PLATFORM_SESSION_IDLE", "fortnight")
	if _, err := Load(); err == nil {
		t.Fatal("want a parse error")
	}
}

// A secret read from a file never enters the process environment, which is where a credential
// leaks from first (child processes inherit it, /proc exposes it). systemd hands one over this way.
func TestSecretsCanComeFromFiles(t *testing.T) {
	path := filepath.Join(t.TempDir(), "dsn")
	if err := os.WriteFile(path, []byte("postgres://u:p@h/db\n"), 0o600); err != nil {
		t.Fatal(err)
	}
	t.Setenv("TM_PLATFORM_DSN_FILE", path)
	c, err := Load()
	if err != nil {
		t.Fatal(err)
	}
	if c.DSN != "postgres://u:p@h/db" {
		t.Fatalf("DSN = %q (trailing newline must be trimmed)", c.DSN)
	}

	t.Setenv("TM_PLATFORM_DSN_FILE", filepath.Join(t.TempDir(), "absent"))
	if _, err := Load(); err == nil {
		t.Fatal("a named secret file that cannot be read must fail at boot, not at the first query")
	}
}

// Half a login configuration mounts a surface that fails at the first click instead of at boot.
func TestPartialOIDCConfigurationIsRefused(t *testing.T) {
	t.Setenv("TM_PLATFORM_OIDC_ISSUER", "https://accounts.google.com")
	t.Setenv("TM_PLATFORM_OIDC_CLIENT_ID", "id")
	if _, err := Load(); err == nil {
		t.Fatal("an issuer without a secret and a redirect must be refused")
	}
	t.Setenv("TM_PLATFORM_OIDC_CLIENT_SECRET", "s")
	t.Setenv("TM_PLATFORM_OIDC_REDIRECT_URL", "https://app.example.org/auth/callback")
	c, err := Load()
	if err != nil {
		t.Fatal(err)
	}
	if !c.LoginEnabled() {
		t.Fatal("a complete configuration must enable sign-in")
	}
}

// The free tier is a number an operator sets, and a bad one must not become a silent zero.
//
// ⚠ The DEFAULT is zero (owner, 16.08 — D39.138 п.2л, register row PD-104): during the beta credit
// is granted by hand. It is pinned here because a self-service grant with no daily aggregate cap
// behind it is bounded only by how fast an attacker can create subjects, and the version of this
// test that read "five dollars" would go green again the moment somebody restored that default
// while looking at something else.
func TestSignupGrantIsParsedNotGuessed(t *testing.T) {
	if c, err := Load(); err != nil || c.SignupGrantMicroUSD != 0 {
		t.Fatalf("default grant = %d (%v)", c.SignupGrantMicroUSD, err)
	}
	t.Setenv("TM_PLATFORM_SIGNUP_GRANT_USD", "2.50")
	c, err := Load()
	if err != nil {
		t.Fatal(err)
	}
	if c.SignupGrantMicroUSD != 2_500_000 {
		t.Fatalf("grant = %d", c.SignupGrantMicroUSD)
	}
	t.Setenv("TM_PLATFORM_SIGNUP_GRANT_USD", "five dollars")
	if _, err := Load(); err == nil {
		t.Fatal("an unparseable grant must fail at boot")
	}
}

// PD-58. The session clocks are a declared conformance point, not a preference: ASVS 5.0 7.1.1
// takes the baseline from NIST SP 800-63B-4, whose AAL1 rule is that the overall reauthentication
// timeout SHOULD be no more than 30 days. The reasoning lives in STACK_DECISIONS §13; this keeps
// the defaults from drifting past it without someone changing that document too.
// Mutation caught: raising either default beyond the norm.
func TestSessionClocksStayWithinTheDeclaredBaseline(t *testing.T) {
	c, err := Load()
	if err != nil {
		t.Fatal(err)
	}
	const aal1Overall = 30 * 24 * time.Hour
	if c.SessionMaxAge > aal1Overall {
		t.Errorf("absolute session lifetime is %s, above the NIST SP 800-63B-4 AAL1 figure of %s: a deviation needs a written justification (ASVS 7.1.1)",
			c.SessionMaxAge, aal1Overall)
	}
	if c.SessionIdleTTL <= 0 || c.SessionIdleTTL > c.SessionMaxAge {
		t.Errorf("idle window is %s against an absolute of %s: an idle window that cannot expire first is not one",
			c.SessionIdleTTL, c.SessionMaxAge)
	}
}

// The runner's settings decide whether a run can start at all, so the failure modes have to be
// visible at LOAD, where an operator is watching, rather than at the first click.
func TestTheRunnerSettingsFailAtLoadAndNotAtTheFirstRun(t *testing.T) {
	t.Setenv("TM_PLATFORM_RUN_TASKS_MAX", "not a number")
	if _, err := Load(); err == nil {
		t.Error("a non-numeric task cap was accepted")
	}
	t.Setenv("TM_PLATFORM_RUN_TASKS_MAX", "0")
	if _, err := Load(); err == nil {
		t.Error("a task cap of zero was accepted")
	}
	t.Setenv("TM_PLATFORM_RUN_TASKS_MAX", "")
	t.Setenv("TM_PLATFORM_USD_PER_CHAPTER", "0")
	if _, err := Load(); err == nil {
		t.Error("a per-chapter rate of zero was accepted: it makes every ceiling free")
	}
	t.Setenv("TM_PLATFORM_USD_PER_CHAPTER", "")
	t.Setenv("TM_PLATFORM_RESYNC_EVERY", "-5m")
	if _, err := Load(); err == nil {
		t.Error("a negative resync interval was accepted")
	}
}

// The default rate is resolved HERE and nowhere else, so there is one answer to "what is this
// instance using" instead of one per caller. (It used to be resolved by the daemon, which meant a
// zero in the config and a real number in the process — found by the owner's question, 08.08.)
func TestThePerChapterRateAlwaysHasAValue(t *testing.T) {
	t.Setenv("TM_PLATFORM_USD_PER_CHAPTER", "")
	c, err := Load()
	if err != nil {
		t.Fatal(err)
	}
	if c.Runner.PerChapterMicroUSD <= 0 {
		t.Fatalf("the rate is %d: the default has to be resolved in config", c.Runner.PerChapterMicroUSD)
	}
	t.Setenv("TM_PLATFORM_USD_PER_CHAPTER", "0.05")
	if c, err = Load(); err != nil || c.Runner.PerChapterMicroUSD != 50_000 {
		t.Fatalf("an explicit rate gave %d (%v)", c.Runner.PerChapterMicroUSD, err)
	}
}

// An instance with no engine binary is a read replica, not a broken one: the library is not run
// machinery, and refusing to start would turn a partial capability into a total outage.
func TestAnInstanceWithoutAnEngineStillLoads(t *testing.T) {
	t.Setenv("TM_PLATFORM_ENGINE_BIN", "")
	c, err := Load()
	if err != nil {
		t.Fatal(err)
	}
	if c.RunsEnabled() {
		t.Error("runs are reported as enabled with no engine binary configured")
	}
}

// ⚠ The one shape of the development sign-in that is dangerous: a deployment with a real identity
// provider AND a keyless door into a session. It is refused at BOOT — the service does not start —
// rather than warned about, because the way it comes about is an operator copying a dev unit file
// onto a host that carries the production environment, and a warning in a log is read by nobody.
//
// Mutation caught: turning the refusal into a log line, and checking only the full OIDC quartet.
func TestTheDevelopmentSignInCannotCoexistWithAnIdentityProvider(t *testing.T) {
	full := map[string]string{
		"TM_PLATFORM_OIDC_ISSUER":        "https://accounts.example.org",
		"TM_PLATFORM_OIDC_CLIENT_ID":     "id",
		"TM_PLATFORM_OIDC_CLIENT_SECRET": "secret",
		"TM_PLATFORM_OIDC_REDIRECT_URL":  "https://app.example.org/auth/callback",
	}
	// Every way an OIDC provider can be present, including the half-configured ones: any of them
	// alongside the dev sign-in must stop the boot.
	for name, env := range map[string]map[string]string{
		"a whole provider":     full,
		"only an issuer":       {"TM_PLATFORM_OIDC_ISSUER": full["TM_PLATFORM_OIDC_ISSUER"]},
		"only a client id":     {"TM_PLATFORM_OIDC_CLIENT_ID": "id"},
		"only a redirect url":  {"TM_PLATFORM_OIDC_REDIRECT_URL": full["TM_PLATFORM_OIDC_REDIRECT_URL"]},
		"only a client secret": {"TM_PLATFORM_OIDC_CLIENT_SECRET": "secret"},
	} {
		t.Run(name, func(t *testing.T) {
			t.Setenv("TM_PLATFORM_DEV_LOGIN", "dev@stand")
			for k, v := range env {
				t.Setenv(k, v)
			}
			if _, err := Load(); err == nil {
				t.Fatal("the service started with both a real identity provider and a development sign-in")
			}
		})
	}
	// And on its own it is legitimate — the stand is the whole point.
	t.Run("on its own", func(t *testing.T) {
		t.Setenv("TM_PLATFORM_DEV_LOGIN", "dev@stand")
		c, err := Load()
		if err != nil {
			t.Fatal(err)
		}
		if !c.DevLoginEnabled() || c.LoginEnabled() {
			t.Errorf("dev=%v oidc=%v", c.DevLoginEnabled(), c.LoginEnabled())
		}
	})
	// Absent, nothing is mounted. This is the default and what every deployment file here sets.
	t.Run("absent by default", func(t *testing.T) {
		c, err := Load()
		if err != nil {
			t.Fatal(err)
		}
		if c.DevLoginEnabled() {
			t.Error("the development sign-in is on without anybody asking for it")
		}
	})
}

// The OTHER half of the same accident, which the acceptance reached with a live daemon: the stand's
// environment sets two variables, and dropping only the sign-in from it left a service issuing real
// Google sessions in cookies without Secure or __Host-, with HSTS off.
//
// What judges it is the deployment's own address rather than a guess: the OIDC callback is this
// platform's public URL, so plain http there IS the stand the switch is for, and anything else
// contradicts it.
//
// Mutation caught: removing the refusal, and judging it by anything other than the callback's scheme.
func TestCookiesWithoutSecureAreRefusedNextToAProductionProvider(t *testing.T) {
	oidc := func(t *testing.T, callback string) {
		t.Helper()
		t.Setenv("TM_PLATFORM_OIDC_ISSUER", "https://accounts.example.org")
		t.Setenv("TM_PLATFORM_OIDC_CLIENT_ID", "id")
		t.Setenv("TM_PLATFORM_OIDC_CLIENT_SECRET", "secret")
		t.Setenv("TM_PLATFORM_OIDC_REDIRECT_URL", callback)
	}
	// Both cases must fail FOR THIS GUARD. An earlier draft carried a third — an empty callback —
	// which passes with the guard deleted, because half a provider is refused by the partial-OIDC
	// check above it (pinned separately by TestPartialOIDCConfigurationIsRefused). A row that stays
	// green under the mutation it is written for is coverage that is not there; found by the
	// cross-family review of this dofix.
	for name, callback := range map[string]string{
		"a public deployment":       "https://app.example.org/auth/callback",
		"a callback nothing parses": "://app.example.org",
	} {
		t.Run(name, func(t *testing.T) {
			t.Setenv("TM_PLATFORM_INSECURE_COOKIES", "1")
			oidc(t, callback)
			if _, err := Load(); err == nil {
				t.Fatal("the service started with a real identity provider and cookies without Secure")
			}
		})
	}
	// A stand that runs a local provider over plain http is legitimate and keeps working: Secure and
	// __Host- cannot be used there at all, so refusing it would only push an operator into a worse
	// arrangement.
	t.Run("a local provider over http", func(t *testing.T) {
		t.Setenv("TM_PLATFORM_INSECURE_COOKIES", "1")
		oidc(t, "http://127.0.0.1:8080/auth/callback")
		c, err := Load()
		if err != nil {
			t.Fatalf("a plain-http stand with a local provider was refused: %v", err)
		}
		if !c.InsecureCookies || !c.LoginEnabled() {
			t.Errorf("insecure=%v oidc=%v", c.InsecureCookies, c.LoginEnabled())
		}
	})
	// And with no provider at all it is the ordinary development switch.
	t.Run("on its own", func(t *testing.T) {
		t.Setenv("TM_PLATFORM_INSECURE_COOKIES", "1")
		c, err := Load()
		if err != nil {
			t.Fatal(err)
		}
		if !c.InsecureCookies {
			t.Error("the development cookie profile did not apply")
		}
	})
}

// The development sign-in's identity namespace is RESERVED, and this is the guard the adversarial
// review of that feature asked for.
//
// The identity key is (provider, subject) and TM_PLATFORM_OIDC_PROVIDER is free-form operator input.
// An issuer configured under the name `dev` therefore files its subjects in the namespace a
// development stand writes into — and a `sub` that equals the dev subject resolves to the DEV
// account, with whatever credit was seeded onto it. That is the account-linking class §10a warns
// about, one env var away.
//
// Mutation caught: removing the reserved-name refusal from Load.
func TestAnIssuerCannotBeConfiguredUnderTheDevelopmentProvidersName(t *testing.T) {
	for _, name := range []string{"dev"} {
		t.Setenv("TM_PLATFORM_OIDC_PROVIDER", name)
		t.Setenv("TM_PLATFORM_OIDC_ISSUER", "https://accounts.example.org")
		t.Setenv("TM_PLATFORM_OIDC_CLIENT_ID", "id")
		t.Setenv("TM_PLATFORM_OIDC_CLIENT_SECRET", "secret")
		t.Setenv("TM_PLATFORM_OIDC_REDIRECT_URL", "https://app.example.org/auth/callback")
		if _, err := Load(); err == nil {
			t.Fatalf("an issuer was accepted under the name %q: its subjects would share the development namespace", name)
		}
	}
	// An ordinary provider name is untouched.
	t.Setenv("TM_PLATFORM_OIDC_PROVIDER", "google")
	if _, err := Load(); err != nil {
		t.Fatalf("an ordinary provider name was refused: %v", err)
	}
}

// "Mounted only when it NAMES a subject" has to mean a subject, not a space. A value of whitespace
// would otherwise mount a keyless sign-in whose identity is " ".
func TestAWhitespaceDevelopmentSubjectMountsNothing(t *testing.T) {
	t.Setenv("TM_PLATFORM_DEV_LOGIN", "   ")
	c, err := Load()
	if err != nil {
		t.Fatal(err)
	}
	if c.DevLoginEnabled() {
		t.Error("a whitespace subject mounted the development sign-in")
	}
}