package anthropic

import (
	"strings"
	"testing"

	api "git.flytoex.net/yuanwei/flyto-agent/internal/transport"
	"git.flytoex.net/yuanwei/flyto-agent/pkg/flyto"
)

// TestBuildRequest_TemperatureTopP_Forwarded 锁 buildRequest 把
// Request.Temperature/TopP 直接透传到 api.MessageRequest 字段.
//
// Locks buildRequest forwarding Request.Temperature/TopP straight into
// the api.MessageRequest fields.
func TestBuildRequest_TemperatureTopP_Forwarded(t *testing.T) {
	p := New(Config{APIKey: "test-key"})
	req := &flyto.Request{
		Model:       "claude-sonnet-4-6",
		MaxTokens:   100,
		Temperature: flyto.Float(0.3),
		TopP:        flyto.Float(0.85),
		Messages:    []flyto.Message{{Role: flyto.RoleUser, Blocks: []flyto.Block{flyto.TextBlock("hi")}}},
	}
	apiReq, err := p.buildRequest(req)
	if err != nil {
		t.Fatalf("buildRequest: %v", err)
	}
	if apiReq.Temperature == nil || *apiReq.Temperature != 0.3 {
		t.Errorf("apiReq.Temperature = %v, want 0.3", apiReq.Temperature)
	}
	if apiReq.TopP == nil || *apiReq.TopP != 0.85 {
		t.Errorf("apiReq.TopP = %v, want 0.85", apiReq.TopP)
	}
}

// TestBuildRequest_NilSampling 锁未设时 apiReq 字段为 nil (omitempty 兜底
// 不传 wire 字段, 上游用 provider 默认).
//
// Locks the nil case: unset sampling knobs leave apiReq fields nil, which
// omitempty later strips from the wire so upstream uses its defaults.
func TestBuildRequest_NilSampling(t *testing.T) {
	p := New(Config{APIKey: "test-key"})
	req := &flyto.Request{
		Model:     "claude-sonnet-4-6",
		MaxTokens: 100,
		Messages:  []flyto.Message{{Role: flyto.RoleUser, Blocks: []flyto.Block{flyto.TextBlock("hi")}}},
	}
	apiReq, err := p.buildRequest(req)
	if err != nil {
		t.Fatalf("buildRequest: %v", err)
	}
	if apiReq.Temperature != nil {
		t.Errorf("apiReq.Temperature = %v, want nil", *apiReq.Temperature)
	}
	if apiReq.TopP != nil {
		t.Errorf("apiReq.TopP = %v, want nil", *apiReq.TopP)
	}
}

// TestApplyThinkingSamplingConstraints_NoThinking_NoOp 锁 thinking 未启用
// 时 helper 不动 apiReq 字段 (绝大多数请求走此分支).
//
// Locks the no-op path: when thinking is not enabled, the helper leaves
// apiReq Temperature/TopP untouched (the common case for most requests).
func TestApplyThinkingSamplingConstraints_NoThinking_NoOp(t *testing.T) {
	apiReq := &api.MessageRequest{
		Temperature: flyto.Float(0.3),
		TopP:        flyto.Float(0.5),
	}
	applyThinkingSamplingConstraints(apiReq)
	if *apiReq.Temperature != 0.3 {
		t.Errorf("Temperature mutated without thinking: got %v", *apiReq.Temperature)
	}
	if *apiReq.TopP != 0.5 {
		t.Errorf("TopP mutated without thinking: got %v", *apiReq.TopP)
	}
}

// TestApplyThinkingSamplingConstraints_TemperatureOverride 锁 thinking
// 启用时, temperature != 1.0 被覆盖为 1.0 (服务端硬约束).
//
// Locks the override behavior: when thinking is enabled, a non-1.0
// temperature is rewritten to 1.0 to comply with Anthropic's server-side
// constraint.
func TestApplyThinkingSamplingConstraints_TemperatureOverride(t *testing.T) {
	apiReq := &api.MessageRequest{
		Thinking:    &api.ThinkingConfig{Type: "enabled", BudgetTokens: 8000},
		Temperature: flyto.Float(0.3),
	}
	applyThinkingSamplingConstraints(apiReq)
	if apiReq.Temperature == nil || *apiReq.Temperature != 1.0 {
		t.Errorf("Temperature with thinking + 0.3 = %v, want 1.0", apiReq.Temperature)
	}
}

// TestApplyThinkingSamplingConstraints_TopPBelowFloor_Override 锁 thinking
// 启用时, top_p < 0.95 被覆盖为 1.0 (Anthropic API 限制 [0.95, 1.0]).
//
// Locks the top_p override: with thinking on, top_p < 0.95 is rewritten
// to 1.0 (Anthropic restricts top_p to [0.95, 1.0] in thinking mode).
func TestApplyThinkingSamplingConstraints_TopPBelowFloor_Override(t *testing.T) {
	apiReq := &api.MessageRequest{
		Thinking: &api.ThinkingConfig{Type: "enabled", BudgetTokens: 8000},
		TopP:     flyto.Float(0.5),
	}
	applyThinkingSamplingConstraints(apiReq)
	if apiReq.TopP == nil || *apiReq.TopP != 1.0 {
		t.Errorf("TopP with thinking + 0.5 = %v, want 1.0 (override)", apiReq.TopP)
	}
}

// TestApplyThinkingSamplingConstraints_TopPInWindow_Untouched 锁
// thinking 启用时, top_p 在 [0.95, 1.0] 窗口内不动 (合法值不覆盖, 否则会丢失
// 调用方意图).
//
// Locks: with thinking on, a top_p already inside [0.95, 1.0] is not
// rewritten -- legal values must survive the override path or caller
// intent is lost.
func TestApplyThinkingSamplingConstraints_TopPInWindow_Untouched(t *testing.T) {
	apiReq := &api.MessageRequest{
		Thinking: &api.ThinkingConfig{Type: "enabled", BudgetTokens: 8000},
		TopP:     flyto.Float(0.97),
	}
	applyThinkingSamplingConstraints(apiReq)
	if *apiReq.TopP != 0.97 {
		t.Errorf("TopP 0.97 (in [0.95, 1.0]) was overridden to %v", *apiReq.TopP)
	}
}

// TestApplyThinkingSamplingConstraints_TemperatureOne_Untouched 锁
// thinking 启用时, temperature == 1.0 不动 (合法值原地保留).
//
// Locks: with thinking on, temperature == 1.0 (the only legal value) is
// not rewritten.
func TestApplyThinkingSamplingConstraints_TemperatureOne_Untouched(t *testing.T) {
	apiReq := &api.MessageRequest{
		Thinking:    &api.ThinkingConfig{Type: "enabled", BudgetTokens: 8000},
		Temperature: flyto.Float(1.0),
	}
	applyThinkingSamplingConstraints(apiReq)
	if *apiReq.Temperature != 1.0 {
		t.Errorf("Temperature 1.0 (legal) was modified to %v", *apiReq.Temperature)
	}
}

// TestDetectFeatureWarnings_ThinkingTemperatureOverride 锁 detectFeatureWarnings
// 在 thinking + temp != 1.0 时发出 parameter_overridden warning, message
// 含被覆盖的具体值, Detail 含 model + parameter 名 (运维 grep 友好).
//
// Locks the WarningEvent emitted when thinking + non-1.0 temperature
// triggers an override: code = parameter_overridden, message includes
// the overridden value, Detail includes model + parameter for ops grep.
func TestDetectFeatureWarnings_ThinkingTemperatureOverride(t *testing.T) {
	p := New(Config{APIKey: "test-key"})
	req := &flyto.Request{
		Model:         "claude-sonnet-4-6",
		NeedsThinking: true,
		Temperature:   flyto.Float(0.3),
	}
	warnings := p.detectFeatureWarnings(req)

	var found *flyto.WarningEvent
	for _, w := range warnings {
		if w.Code == "parameter_overridden" && strings.Contains(w.Detail, "parameter=temperature") {
			found = w
			break
		}
	}
	if found == nil {
		t.Fatalf("expected parameter_overridden warning for temperature, got %+v", warnings)
	}
	if !strings.Contains(found.Message, "0.3") {
		t.Errorf("warning Message should mention overridden value 0.3, got %q", found.Message)
	}
	if !strings.Contains(found.Detail, "claude-sonnet-4-6") {
		t.Errorf("warning Detail should mention model, got %q", found.Detail)
	}
}

// TestDetectFeatureWarnings_ThinkingTopPOverride 锁 thinking + topP < 0.95
// 时发 parameter_overridden warning, parameter=top_p, message 含原值.
//
// Locks the WarningEvent for the top_p override path: parameter=top_p
// in Detail, original value present in Message.
func TestDetectFeatureWarnings_ThinkingTopPOverride(t *testing.T) {
	p := New(Config{APIKey: "test-key"})
	req := &flyto.Request{
		Model:         "claude-sonnet-4-6",
		NeedsThinking: true,
		TopP:          flyto.Float(0.5),
	}
	warnings := p.detectFeatureWarnings(req)

	var found *flyto.WarningEvent
	for _, w := range warnings {
		if w.Code == "parameter_overridden" && strings.Contains(w.Detail, "parameter=top_p") {
			found = w
			break
		}
	}
	if found == nil {
		t.Fatalf("expected parameter_overridden warning for top_p, got %+v", warnings)
	}
	if !strings.Contains(found.Message, "0.5") {
		t.Errorf("warning Message should mention overridden value 0.5, got %q", found.Message)
	}
}

// TestDetectFeatureWarnings_NoThinking_NoOverrideWarning 锁未启用 thinking
// 时绝不发 parameter_overridden warning (绝大多数请求走此分支, 防止 noise).
//
// Locks: without thinking enabled, no parameter_overridden warning is
// emitted -- the common path must stay quiet.
func TestDetectFeatureWarnings_NoThinking_NoOverrideWarning(t *testing.T) {
	p := New(Config{APIKey: "test-key"})
	req := &flyto.Request{
		Model:       "claude-sonnet-4-6", // thinking 未启用
		Temperature: flyto.Float(0.3),
		TopP:        flyto.Float(0.5),
	}
	warnings := p.detectFeatureWarnings(req)
	for _, w := range warnings {
		if w.Code == "parameter_overridden" {
			t.Errorf("unexpected parameter_overridden warning without thinking: %+v", w)
		}
	}
}

// TestDetectFeatureWarnings_ThinkingLegalValues_NoWarning 锁 thinking 启用
// 但 temperature == 1.0 + topP 在 [0.95, 1.0] 时不发 override warning
// (合法值不应误报).
//
// Locks: with thinking on but temperature == 1.0 and top_p in [0.95, 1.0]
// (both legal), no override warning is emitted.
func TestDetectFeatureWarnings_ThinkingLegalValues_NoWarning(t *testing.T) {
	p := New(Config{APIKey: "test-key"})
	req := &flyto.Request{
		Model:         "claude-sonnet-4-6",
		NeedsThinking: true,
		Temperature:   flyto.Float(1.0),
		TopP:          flyto.Float(0.97),
	}
	warnings := p.detectFeatureWarnings(req)
	for _, w := range warnings {
		if w.Code == "parameter_overridden" {
			t.Errorf("unexpected override warning for legal thinking values: %+v", w)
		}
	}
}