package config

import (
	"os"
	"path/filepath"
	"reflect"
	"strings"
	"testing"
	"time"
)

func writeEnvFile(t *testing.T, content string) string {
	t.Helper()
	dir := t.TempDir()
	path := filepath.Join(dir, ".env")
	if err := os.WriteFile(path, []byte(content), 0o600); err != nil {
		t.Fatalf("write env file: %v", err)
	}
	return path
}

func TestLoad_DefaultsWhenUnset(t *testing.T) {
	t.Setenv("JWT_SECRET", strings.Repeat("s", 40))

	cfg, err := Load("")
	if err != nil {
		t.Fatalf("Load() error: %v", err)
	}

	if cfg.Env != "development" {
		t.Errorf("Env = %q, want development", cfg.Env)
	}
	if cfg.Server.Host != "0.0.0.0" || cfg.Server.Port != 8080 {
		t.Errorf("Server = %+v, want 0.0.0.0:8080", cfg.Server)
	}
	if cfg.LogLevel != "debug" {
		t.Errorf("LogLevel = %q, want debug", cfg.LogLevel)
	}
	if cfg.DB.SQLitePath != "./data/cyrene.db" {
		t.Errorf("SQLitePath = %q, want ./data/cyrene.db", cfg.DB.SQLitePath)
	}
	want := []string{"http://localhost:5173", "http://localhost:3000"}
	if !reflect.DeepEqual(cfg.AllowedOrigins, want) {
		t.Errorf("AllowedOrigins = %v, want %v", cfg.AllowedOrigins, want)
	}
}

func TestLoad_EnvOverridesDefault(t *testing.T) {
	t.Setenv("JWT_SECRET", strings.Repeat("s", 40))
	t.Setenv("PORT", "9090")
	t.Setenv("LOG_LEVEL", "warn")
	t.Setenv("IOT_PROVIDER", "none")

	cfg, err := Load("")
	if err != nil {
		t.Fatalf("Load() error: %v", err)
	}
	if cfg.Server.Port != 9090 {
		t.Errorf("Port = %d, want 9090", cfg.Server.Port)
	}
	if cfg.LogLevel != "warn" {
		t.Errorf("LogLevel = %q, want warn", cfg.LogLevel)
	}
	if cfg.IoT.Provider != "none" {
		t.Errorf("IoT.Provider = %q, want none", cfg.IoT.Provider)
	}
}

func TestLoad_PushOutletEnv(t *testing.T) {
	t.Setenv("JWT_SECRET", strings.Repeat("s", 40))
	t.Setenv("PUSH_EXPORTER_ENABLED", "true")
	t.Setenv("PUSH_EXPORTER_URL", "https://push.example.com/hook")
	t.Setenv("PUSH_EXPORTER_TOKEN", "tok")
	t.Setenv("PUSH_EXPORTER_TIMEOUT_SEC", "9")
	t.Setenv("GETUI_APP_ID", "app-id")

	cfg, err := Load("")
	if err != nil {
		t.Fatalf("Load() error: %v", err)
	}
	if !cfg.PushOutlet.Enabled {
		t.Error("PushOutlet.Enabled = false, want true")
	}
	if cfg.PushOutlet.URL != "https://push.example.com/hook" {
		t.Errorf("PushOutlet.URL = %q, want the configured endpoint", cfg.PushOutlet.URL)
	}
	if cfg.PushOutlet.Token != "tok" {
		t.Errorf("PushOutlet.Token = %q, want tok", cfg.PushOutlet.Token)
	}
	if cfg.PushOutlet.TimeoutSec != 9 {
		t.Errorf("PushOutlet.TimeoutSec = %d, want 9", cfg.PushOutlet.TimeoutSec)
	}
	if cfg.PushOutlet.GetuiAppID != "app-id" {
		t.Errorf("PushOutlet.GetuiAppID = %q, want app-id", cfg.PushOutlet.GetuiAppID)
	}
}

func TestLoad_DotEnvThenProcessEnv(t *testing.T) {
	path := writeEnvFile(t, `PORT=7000
LOG_LEVEL=error
# comment line
IOT_PROVIDER=none
`)
	// Process env overrides .env for PORT but leaves LOG_LEVEL from .env.
	t.Setenv("JWT_SECRET", strings.Repeat("s", 40))
	t.Setenv("PORT", "8000")

	cfg, err := Load(path)
	if err != nil {
		t.Fatalf("Load(%q) error: %v", path, err)
	}
	if cfg.Server.Port != 8000 {
		t.Errorf("Port = %d, want 8000 (process env wins)", cfg.Server.Port)
	}
	if cfg.LogLevel != "error" {
		t.Errorf("LogLevel = %q, want error from .env", cfg.LogLevel)
	}
	if cfg.IoT.Provider != "none" {
		t.Errorf("IoT.Provider = %q, want none from .env", cfg.IoT.Provider)
	}
}

// unsetEnvForTest clears key for the test and restores the original value (or
// absence) on cleanup, so a .env file is not shadowed by an ambient process env
// variable. config tests are not parallel, so this is safe.
func unsetEnvForTest(t *testing.T, key string) {
	t.Helper()
	if v, ok := os.LookupEnv(key); ok {
		t.Cleanup(func() { _ = os.Setenv(key, v) })
	} else {
		t.Cleanup(func() { _ = os.Unsetenv(key) })
	}
	if err := os.Unsetenv(key); err != nil {
		t.Fatalf("unset %s: %v", key, err)
	}
}

func TestLoad_LlmFallbackMaxTokens(t *testing.T) {
	t.Setenv("JWT_SECRET", strings.Repeat("s", 40))
	unsetEnvForTest(t, "LLM_FALLBACK_MAX_TOKENS")

	// Default: the last-resort fallback budget is a meaningful 8192.
	cfg, err := Load("")
	if err != nil {
		t.Fatalf("Load() error: %v", err)
	}
	if cfg.LLM.FallbackMaxTokens != 8192 {
		t.Errorf("LLM.FallbackMaxTokens = %d, want default 8192", cfg.LLM.FallbackMaxTokens)
	}

	// A .env file is parsed into the field.
	path := writeEnvFile(t, "LLM_FALLBACK_MAX_TOKENS=4096\n")
	cfg, err = Load(path)
	if err != nil {
		t.Fatalf("Load(%q) error: %v", path, err)
	}
	if cfg.LLM.FallbackMaxTokens != 4096 {
		t.Errorf("LLM.FallbackMaxTokens = %d, want 4096 from .env", cfg.LLM.FallbackMaxTokens)
	}

	// Process env wins over .env.
	t.Setenv("LLM_FALLBACK_MAX_TOKENS", "2048")
	cfg, err = Load(path)
	if err != nil {
		t.Fatalf("Load(%q) error: %v", path, err)
	}
	if cfg.LLM.FallbackMaxTokens != 2048 {
		t.Errorf("LLM.FallbackMaxTokens = %d, want 2048 (process env wins)", cfg.LLM.FallbackMaxTokens)
	}
}

// TestLoad_LlmMultimodal 钉住 LLM_MULTIMODAL 的解码面（裁决 14.4.1）：默认 false
// （= 与引入本键之前逐字节一致）、.env 与进程 env 两条路都能声明、非法值**报错**
// 而不是静默回退成 false（静默的「配了当没配」正是本键要消灭的东西）。
func TestLoad_LlmMultimodal(t *testing.T) {
	t.Setenv("JWT_SECRET", strings.Repeat("s", 40))
	unsetEnvForTest(t, "LLM_MULTIMODAL")

	cfg, err := Load("")
	if err != nil {
		t.Fatalf("Load() error: %v", err)
	}
	if cfg.LLM.Multimodal {
		t.Error("LLM.Multimodal = true, want default false")
	}

	path := writeEnvFile(t, "LLM_MULTIMODAL=true\n")
	cfg, err = Load(path)
	if err != nil {
		t.Fatalf("Load(%q) error: %v", path, err)
	}
	if !cfg.LLM.Multimodal {
		t.Error("LLM.Multimodal = false, want true from .env")
	}

	t.Setenv("LLM_MULTIMODAL", "maybe")
	if _, err := Load(""); err == nil {
		t.Fatal("expected an error for LLM_MULTIMODAL=maybe, got nil")
	} else if !strings.Contains(err.Error(), "LLM_MULTIMODAL") {
		t.Errorf("error should mention LLM_MULTIMODAL, got: %v", err)
	}
}

func TestLoad_MissingRequiredFails(t *testing.T) {
	// Do not set JWT_SECRET.
	if _, err := Load(""); err == nil {
		t.Fatal("expected error when JWT_SECRET missing, got nil")
	} else if !strings.Contains(err.Error(), "JWT_SECRET") {
		t.Errorf("error should mention JWT_SECRET, got: %v", err)
	}
}

func TestLoad_ValidationMinLength(t *testing.T) {
	t.Setenv("JWT_SECRET", "short")
	if _, err := Load(""); err == nil {
		t.Fatal("expected error for JWT_SECRET shorter than 32, got nil")
	} else if !strings.Contains(err.Error(), "at least 32") {
		t.Errorf("error should mention min length, got: %v", err)
	}
}

func TestLoad_InvalidPortFails(t *testing.T) {
	t.Setenv("JWT_SECRET", strings.Repeat("s", 40))
	t.Setenv("PORT", "not-a-number")
	if _, err := Load(""); err == nil {
		t.Fatal("expected error for invalid PORT, got nil")
	} else if !strings.Contains(err.Error(), "PORT") {
		t.Errorf("error should mention PORT, got: %v", err)
	}
}

func TestLoad_MissingDotEnvIsTolerated(t *testing.T) {
	t.Setenv("JWT_SECRET", strings.Repeat("s", 40))
	// A non-existent .env path must not error.
	cfg, err := Load(filepath.Join(t.TempDir(), "does-not-exist.env"))
	if err != nil {
		t.Fatalf("Load(nonexistent) error: %v", err)
	}
	if cfg.Server.Port != 8080 {
		t.Errorf("Port = %d, want default 8080", cfg.Server.Port)
	}
}

func TestLoad_AuthRefreshDefaults(t *testing.T) {
	t.Setenv("JWT_SECRET", strings.Repeat("s", 40))

	cfg, err := Load("")
	if err != nil {
		t.Fatalf("Load() error: %v", err)
	}
	if cfg.Auth.RefreshTTL != 720*time.Hour {
		t.Errorf("Auth.RefreshTTL = %v, want 720h", cfg.Auth.RefreshTTL)
	}
	if cfg.Auth.RefreshRotateDisabled {
		t.Errorf("Auth.RefreshRotateDisabled = true, want false (rotation on by default)")
	}
}

func TestLoad_AuthRefreshEnvOverrides(t *testing.T) {
	t.Setenv("JWT_SECRET", strings.Repeat("s", 40))
	t.Setenv("AUTH_REFRESH_TTL", "30m")
	t.Setenv("AUTH_REFRESH_ROTATE_DISABLED", "true")

	cfg, err := Load("")
	if err != nil {
		t.Fatalf("Load() error: %v", err)
	}
	if cfg.Auth.RefreshTTL != 30*time.Minute {
		t.Errorf("Auth.RefreshTTL = %v, want 30m", cfg.Auth.RefreshTTL)
	}
	if !cfg.Auth.RefreshRotateDisabled {
		t.Errorf("Auth.RefreshRotateDisabled = false, want true")
	}
}

func TestLoad_CapacityDefaults(t *testing.T) {
	t.Setenv("JWT_SECRET", strings.Repeat("s", 40))

	cfg, err := Load("")
	if err != nil {
		t.Fatalf("Load() error: %v", err)
	}
	if cfg.Capacity.Enabled {
		t.Errorf("Capacity.Enabled = true, want false (default, opt-in)")
	}
	if cfg.Capacity.MinConfidence != 0.6 {
		t.Errorf("Capacity.MinConfidence = %v, want 0.6", cfg.Capacity.MinConfidence)
	}
}
func TestLoad_CapacityEnvOverrides(t *testing.T) {
	t.Setenv("JWT_SECRET", strings.Repeat("s", 40))
	t.Setenv("CAPACITY_ENABLED", "true")
	t.Setenv("CAPACITY_MIN_CONFIDENCE", "0.75")

	cfg, err := Load("")
	if err != nil {
		t.Fatalf("Load() error: %v", err)
	}
	if !cfg.Capacity.Enabled {
		t.Errorf("Capacity.Enabled = false, want true")
	}
	if cfg.Capacity.MinConfidence != 0.75 {
		t.Errorf("Capacity.MinConfidence = %v, want 0.75", cfg.Capacity.MinConfidence)
	}
}

func TestLoad_VoiceDefaults(t *testing.T) {
	t.Setenv("JWT_SECRET", strings.Repeat("s", 40))

	cfg, err := Load("")
	if err != nil {
		t.Fatalf("Load() error: %v", err)
	}
	if cfg.Voice.DashscopeBaseURL != "https://dashscope.aliyuncs.com/api/v1" {
		t.Errorf("DashscopeBaseURL = %q, want the default Bailian URL", cfg.Voice.DashscopeBaseURL)
	}
	if cfg.Voice.STTModel != "qwen-audio-3.0-asr-flash" {
		t.Errorf("STTModel = %q, want qwen-audio-3.0-asr-flash", cfg.Voice.STTModel)
	}
	if cfg.Voice.STTLanguage != "zh" {
		t.Errorf("STTLanguage = %q, want zh", cfg.Voice.STTLanguage)
	}
	if cfg.Voice.TTSModel != "cosyvoice-v3-flash" {
		t.Errorf("TTSModel = %q, want cosyvoice-v3-flash", cfg.Voice.TTSModel)
	}
	if cfg.Voice.TTSVoiceID != "longxiaochun_v3" {
		t.Errorf("TTSVoiceID = %q, want longxiaochun_v3", cfg.Voice.TTSVoiceID)
	}
	if cfg.Voice.TTSFormat != "wav" {
		t.Errorf("TTSFormat = %q, want wav", cfg.Voice.TTSFormat)
	}
	if cfg.Voice.TTSSampleRate != 24000 {
		t.Errorf("TTSSampleRate = %d, want 24000", cfg.Voice.TTSSampleRate)
	}
	if cfg.Voice.VoiceTTSInstruction != "" {
		t.Errorf("VoiceTTSInstruction = %q, want empty (default)", cfg.Voice.VoiceTTSInstruction)
	}
	if cfg.Voice.VoiceClonePrefix != "cyrene" {
		t.Errorf("VoiceClonePrefix = %q, want cyrene (default)", cfg.Voice.VoiceClonePrefix)
	}
}

func TestLoad_VoiceEnvOverrides(t *testing.T) {
	t.Setenv("JWT_SECRET", strings.Repeat("s", 40))
	t.Setenv("VOICE_TTS_VOICE_ID", "custom-voice-1")
	t.Setenv("VOICE_STT_MODEL", "qwen-audio-3.0-asr-flash")

	cfg, err := Load("")
	if err != nil {
		t.Fatalf("Load() error: %v", err)
	}
	if cfg.Voice.TTSVoiceID != "custom-voice-1" {
		t.Errorf("TTSVoiceID = %q, want custom-voice-1", cfg.Voice.TTSVoiceID)
	}
	if cfg.Voice.STTModel != "qwen-audio-3.0-asr-flash" {
		t.Errorf("STTModel = %q, want qwen-audio-3.0-asr-flash", cfg.Voice.STTModel)
	}
}

func TestLoad_VoiceCloneInstructionEnvOverrides(t *testing.T) {
	t.Setenv("JWT_SECRET", strings.Repeat("s", 40))
	t.Setenv("VOICE_TTS_INSTRUCTION", "语气开朗俏皮，像女朋友撒娇")
	t.Setenv("VOICE_CLONE_PREFIX", "xilian")

	cfg, err := Load("")
	if err != nil {
		t.Fatalf("Load() error: %v", err)
	}
	if cfg.Voice.VoiceTTSInstruction != "语气开朗俏皮，像女朋友撒娇" {
		t.Errorf("VoiceTTSInstruction = %q, want the env instruction", cfg.Voice.VoiceTTSInstruction)
	}
	if cfg.Voice.VoiceClonePrefix != "xilian" {
		t.Errorf("VoiceClonePrefix = %q, want xilian", cfg.Voice.VoiceClonePrefix)
	}
}

func TestParseDotEnv_QuotedAndExport(t *testing.T) {
	path := writeEnvFile(t, `export FOO=bar
BAZ='quoted value'
EMPTY=
`)
	m, err := parseDotEnv(path)
	if err != nil {
		t.Fatalf("parseDotEnv error: %v", err)
	}
	if m["FOO"] != "bar" {
		t.Errorf("FOO = %q, want bar", m["FOO"])
	}
	if m["BAZ"] != "quoted value" {
		t.Errorf("BAZ = %q, want 'quoted value'", m["BAZ"])
	}
	if v, ok := m["EMPTY"]; !ok || v != "" {
		t.Errorf("EMPTY = %q (present=%v), want empty", v, ok)
	}
}

// TestLoad_SubagentTimeout 验证子代理时限配置（design/05 §7 裁决 02.4.4：
// agent_timeout 可配置，默认 10min）：缺省 600 秒，环境变量可覆盖。
func TestLoad_SubagentTimeout(t *testing.T) {
	t.Setenv("JWT_SECRET", strings.Repeat("s", 40))

	cfg, err := Load("")
	if err != nil {
		t.Fatalf("Load() error: %v", err)
	}
	if cfg.Subagent.TimeoutSec != 600 {
		t.Errorf("Subagent.TimeoutSec = %d, want the 600s (10min) default", cfg.Subagent.TimeoutSec)
	}

	t.Setenv("SUBAGENT_TIMEOUT_SEC", "90")
	cfg, err = Load("")
	if err != nil {
		t.Fatalf("Load() with override error: %v", err)
	}
	if cfg.Subagent.TimeoutSec != 90 {
		t.Errorf("Subagent.TimeoutSec = %d, want 90 from the environment", cfg.Subagent.TimeoutSec)
	}
}