package convert

import (
	"encoding/json"
	"testing"
)

func TestChatToMessages(t *testing.T) {
	maxTokens := 1024
	temp := 0.7

	req := &ChatCompletionRequest{
		Model: "claude-3-sonnet-20240229",
		Messages: []Message{
			{Role: "system", Content: "You are a helpful assistant."},
			{Role: "user", Content: "Hello!"},
		},
		MaxTokens: &maxTokens,
		Temperature: &temp,
	}

	result, err := ChatToMessages(req)
	if err != nil {
		t.Fatalf("ChatToMessages() error = %v", err)
	}

	if result.Model != "claude-3-sonnet-20240229" {
		t.Errorf("Model = %q, want %q", result.Model, "claude-3-sonnet-20240229")
	}

	if len(result.Messages) != 1 {
		t.Errorf("Messages length = %d, want 1", len(result.Messages))
	}

	if result.Messages[0].Role != "user" {
		t.Errorf("Messages[0].Role = %q, want %q", result.Messages[0].Role, "user")
	}

	if result.System == nil {
		t.Error("System is nil, want non-nil")
	}

	if result.MaxTokens != 1024 {
		t.Errorf("MaxTokens = %d, want 1024", result.MaxTokens)
	}
}

func TestMessagesToChat(t *testing.T) {
	resp := &MessagesResponse{
		ID:   "msg-123",
		Model: "claude-3-sonnet-20240229",
		Content: []ContentBlock{
			{Type: "text", Text: "Hello! How can I help?"},
		},
		StopReason: "end_turn",
		Usage: Usage{
			PromptTokens:     10,
			CompletionTokens: 20,
		},
	}

	result, err := MessagesToChat(resp)
	if err != nil {
		t.Fatalf("MessagesToChat() error = %v", err)
	}

	if result.ID != "msg-123" {
		t.Errorf("ID = %q, want %q", result.ID, "msg-123")
	}

	if result.Object != "chat.completion" {
		t.Errorf("Object = %q, want %q", result.Object, "chat.completion")
	}

	if len(result.Choices) != 1 {
		t.Errorf("Choices length = %d, want 1", len(result.Choices))
		return
	}

	if result.Choices[0].Message.Role != "assistant" {
		t.Errorf("Choices[0].Message.Role = %q, want %q", result.Choices[0].Message.Role, "assistant")
	}

	if result.Choices[0].Message.Content != "Hello! How can I help?" {
		t.Errorf("Choices[0].Message.Content = %q, want %q", result.Choices[0].Message.Content, "Hello! How can I help?")
	}

	if result.Choices[0].FinishReason != "stop" {
		t.Errorf("FinishReason = %q, want %q", result.Choices[0].FinishReason, "stop")
	}

	if result.Usage.TotalTokens != 30 {
		t.Errorf("Usage.TotalTokens = %d, want 30", result.Usage.TotalTokens)
	}
}

func TestChatToResponses(t *testing.T) {
	maxTokens := 2048

	req := &ChatCompletionRequest{
		Model: "gpt-4o",
		Messages: []Message{
			{Role: "system", Content: "You are a helpful assistant."},
			{Role: "user", Content: "What is 2+2?"},
		},
		MaxTokens: &maxTokens,
	}

	result, err := ChatToResponses(req)
	if err != nil {
		t.Fatalf("ChatToResponses() error = %v", err)
	}

	if result.Model != "gpt-4o" {
		t.Errorf("Model = %q, want %q", result.Model, "gpt-4o")
	}

	if len(result.Input) == 0 {
		t.Errorf("Input empty, want 1 item")
	} else {
		var items []InputItem
		if err := json.Unmarshal(result.Input, &items); err != nil {
			t.Fatalf("Input unmarshal = %v", err)
		}
		if len(items) != 1 {
			t.Errorf("Input length = %d, want 1", len(items))
		} else if items[0].Role != "user" {
			t.Errorf("Input[0].Role = %q, want %q", items[0].Role, "user")
		}
	}

	if result.Instructions != "You are a helpful assistant." {
		t.Errorf("Instructions = %q, want %q", result.Instructions, "You are a helpful assistant.")
	}
}

func TestResponsesToChat(t *testing.T) {
	resp := &ResponsesResponse{
		ID:     "resp-123",
		Model:  "gpt-4o",
		Status: "completed",
		Output: []OutputItem{
			{
				Type: "message",
				Content: []OutputContent{
					{Type: "output_text", Text: "2+2 equals 4."},
				},
			},
		},
		Usage: Usage{
			PromptTokens:     15,
			CompletionTokens: 10,
		},
	}

	result, err := ResponsesToChat(resp)
	if err != nil {
		t.Fatalf("ResponsesToChat() error = %v", err)
	}

	if result.ID != "resp-123" {
		t.Errorf("ID = %q, want %q", result.ID, "resp-123")
	}

	if len(result.Choices) != 1 {
		t.Errorf("Choices length = %d, want 1", len(result.Choices))
		return
	}

	if result.Choices[0].Message.Content != "2+2 equals 4." {
		t.Errorf("Content = %q, want %q", result.Choices[0].Message.Content, "2+2 equals 4.")
	}
}

func TestMapStopReason(t *testing.T) {
	tests := []struct {
		input    string
		expected string
	}{
		{"end_turn", "stop"},
		{"stop_sequence", "stop"},
		{"tool_use", "tool_calls"},
		{"max_tokens", "length"},
		{"unknown", "stop"},
	}

	for _, tt := range tests {
		t.Run(tt.input, func(t *testing.T) {
			result := mapStopReason(tt.input)
			if result != tt.expected {
				t.Errorf("mapStopReason(%q) = %q, want %q", tt.input, result, tt.expected)
			}
		})
	}
}

func TestMessagesToChatToolUse(t *testing.T) {
	resp := &MessagesResponse{
		ID:   "msg-456",
		Model: "claude-3-sonnet-20240229",
		Content: []ContentBlock{
			{Type: "text", Text: "Let me search for that."},
			{Type: "tool_use", ID: "toolu-123", Name: "web_search"},
		},
		StopReason: "tool_use",
		Usage: Usage{
			PromptTokens:     20,
			CompletionTokens: 30,
		},
	}

	result, err := MessagesToChat(resp)
	if err != nil {
		t.Fatalf("MessagesToChat() error = %v", err)
	}

	if len(result.Choices) != 1 {
		t.Errorf("Choices length = %d, want 1", len(result.Choices))
		return
	}

	if result.Choices[0].FinishReason != "tool_calls" {
		t.Errorf("FinishReason = %q, want %q", result.Choices[0].FinishReason, "tool_calls")
	}

	if len(result.Choices[0].Message.ToolCalls) != 1 {
		t.Errorf("ToolCalls length = %d, want 1", len(result.Choices[0].Message.ToolCalls))
		return
	}

	if result.Choices[0].Message.ToolCalls[0].ID != "toolu-123" {
		t.Errorf("ToolCall ID = %q, want %q", result.Choices[0].Message.ToolCalls[0].ID, "toolu-123")
	}

	if result.Choices[0].Message.ToolCalls[0].Function.Name != "web_search" {
		t.Errorf("Function.Name = %q, want %q", result.Choices[0].Message.ToolCalls[0].Function.Name, "web_search")
	}
}