// https://github.com/google-gemini/api-examples/
// https://ai.google.dev/gemini-api/docs/models?hl=zh-cn

package google

import (
	"context"
	"encoding/base64"
	"fmt"
	"net/http"
	"net/url"
	"opencatd-open/internal/model"
	"opencatd-open/llm"
	"os"
	"strings"

	"github.com/sashabaranov/go-openai"

	"google.golang.org/genai"
)

type Gemini struct {
	Ctx        context.Context
	Client     *genai.Client
	ApiKey     *model.ApiKey
	tokenUsage *llm.TokenUsage

	Done chan struct{}
}

func NewGemini(ctx context.Context, apiKey *model.ApiKey) (*Gemini, error) {
	hc := http.DefaultClient
	if os.Getenv("LOCAL_PROXY") != "" {
		proxyUrl, err := url.Parse(os.Getenv("LOCAL_PROXY"))
		if err == nil {
			hc = &http.Client{Transport: &http.Transport{Proxy: http.ProxyURL(proxyUrl)}}
		}
	}
	client, err := genai.NewClient(ctx, &genai.ClientConfig{
		APIKey:     *apiKey.ApiKey,
		Backend:    genai.BackendGeminiAPI,
		HTTPClient: hc,
	})
	if err != nil {
		return nil, err
	}

	return &Gemini{
		Ctx:        context.Background(),
		Client:     client,
		ApiKey:     apiKey,
		tokenUsage: &llm.TokenUsage{},
		Done:       make(chan struct{}),
	}, nil

}

func (g *Gemini) Chat(ctx context.Context, chatReq llm.ChatRequest) (*llm.ChatResponse, error) {
	var content []*genai.Content
	if len(chatReq.Messages) > 0 {
		for _, msg := range chatReq.Messages {
			var role genai.Role
			if msg.Role == "user" || msg.Role == "system" {
				role = genai.RoleUser
			} else {
				role = genai.RoleModel
			}

			if len(msg.MultiContent) > 0 {
				for _, c := range msg.MultiContent {
					var parts []*genai.Part

					if c.Type == "text" {
						parts = append(parts, genai.NewPartFromText(c.Text))
					}
					if c.Type == "image_url" {
						if strings.HasPrefix(c.ImageURL.URL, "http") {
							continue
						}
						if strings.HasPrefix(c.ImageURL.URL, "data:image") {
							var mediaType string
							if strings.HasPrefix(c.ImageURL.URL, "data:image/jpeg") {
								mediaType = "image/jpeg"
							}
							if strings.HasPrefix(c.ImageURL.URL, "data:image/png") {
								mediaType = "image/png"
							}
							imageString := strings.Split(c.ImageURL.URL, ",")[1]
							imageBytes, _ := base64.StdEncoding.DecodeString(imageString)

							parts = append(parts, genai.NewPartFromBytes(imageBytes, mediaType))
						}

					}
					content = append(content, genai.NewContentFromParts(parts, role))
				}
			} else {
				content = append(content, genai.NewContentFromText(msg.Content, role))
			}

		}
	}

	tools := []*genai.Tool{{GoogleSearch: &genai.GoogleSearch{}}}
	response, err := g.Client.Models.GenerateContent(g.Ctx,
		chatReq.Model,
		content,
		&genai.GenerateContentConfig{Tools: tools})
	if err != nil {
		return nil, err
	}

	if g.tokenUsage.Model == "" && response.ModelVersion != "" {
		g.tokenUsage.Model = response.ModelVersion
	}
	if response.UsageMetadata != nil {
		g.tokenUsage.PromptTokens += int(response.UsageMetadata.PromptTokenCount)
		g.tokenUsage.CompletionTokens += int(response.UsageMetadata.CandidatesTokenCount)
		g.tokenUsage.ToolsTokens += int(response.UsageMetadata.ToolUsePromptTokenCount)
		g.tokenUsage.TotalTokens += int(response.UsageMetadata.TotalTokenCount)
	}

	// var text string
	// if response.Candidates != nil && response.Candidates[0].Content != nil {
	// 	for _, part := range response.Candidates[0].Content.Parts {
	// 		text += part.Text
	// 	}
	// }

	return &llm.ChatResponse{
		Model: response.ModelVersion,
		Choices: []openai.ChatCompletionChoice{
			{
				Message:      openai.ChatCompletionMessage{Content: response.Text(), Role: "assistant"},
				FinishReason: openai.FinishReason(response.Candidates[0].FinishReason),
			},
		},
		Usage: openai.Usage{PromptTokens: g.tokenUsage.PromptTokens + g.tokenUsage.ToolsTokens, CompletionTokens: g.tokenUsage.CompletionTokens, TotalTokens: g.tokenUsage.TotalTokens},
	}, nil

}

func (g *Gemini) StreamChat(ctx context.Context, chatReq llm.ChatRequest) (chan *llm.StreamChatResponse, error) {
	var contents []*genai.Content
	if len(chatReq.Messages) > 0 {
		for _, msg := range chatReq.Messages {
			var role genai.Role
			if msg.Role == "user" {
				role = genai.RoleUser
			} else {
				role = genai.RoleModel
			}

			if len(msg.MultiContent) > 0 {
				for _, c := range msg.MultiContent {
					var parts []*genai.Part

					if c.Type == "text" {
						parts = append(parts, genai.NewPartFromText(c.Text))
					}
					if c.Type == "image_url" {
						if strings.HasPrefix(c.ImageURL.URL, "http") {
							continue
						}
						if strings.HasPrefix(c.ImageURL.URL, "data:image") {
							var mediaType string
							if strings.HasPrefix(c.ImageURL.URL, "data:image/jpeg") {
								mediaType = "image/jpeg"
							}
							if strings.HasPrefix(c.ImageURL.URL, "data:image/png") {
								mediaType = "image/png"
							}
							imageString := strings.Split(c.ImageURL.URL, ",")[1]
							imageBytes, _ := base64.StdEncoding.DecodeString(imageString)

							parts = append(parts, genai.NewPartFromBytes(imageBytes, mediaType))
						}

					}
					contents = append(contents, genai.NewContentFromParts(parts, role))
				}
			} else {
				contents = append(contents, genai.NewContentFromText(msg.Content, role))
			}

		}
	}

	datachan := make(chan *llm.StreamChatResponse)
	var generr error

	tools := []*genai.Tool{{GoogleSearch: &genai.GoogleSearch{}}}

	go func() {
		defer close(datachan)
		for result, err := range g.Client.Models.GenerateContentStream(g.Ctx, chatReq.Model, contents, &genai.GenerateContentConfig{Tools: tools}) {
			if err != nil {
				fmt.Println(err)
				generr = err
				return
			}
			if result.UsageMetadata != nil {
				g.tokenUsage.PromptTokens += int(result.UsageMetadata.PromptTokenCount)
				g.tokenUsage.CompletionTokens += int(result.UsageMetadata.CandidatesTokenCount)
				g.tokenUsage.ToolsTokens += int(result.UsageMetadata.ToolUsePromptTokenCount)
				g.tokenUsage.TotalTokens += int(result.UsageMetadata.TotalTokenCount)
			}

			datachan <- &llm.StreamChatResponse{
				Model: result.ModelVersion,
				Choices: []openai.ChatCompletionStreamChoice{
					{
						Delta: openai.ChatCompletionStreamChoiceDelta{
							Role: "assistant",
							// Content: result.Candidates[0].Content.Parts[0].Text,
							Content: result.Text(),
						},
						FinishReason: openai.FinishReason(result.Candidates[0].FinishReason),
					},
				},
				Usage: &openai.Usage{PromptTokens: g.tokenUsage.PromptTokens + g.tokenUsage.ToolsTokens, CompletionTokens: g.tokenUsage.CompletionTokens, TotalTokens: g.tokenUsage.TotalTokens},
			}

		}
	}()

	return datachan, generr
}

func (g *Gemini) GetTokenUsage() *llm.TokenUsage {
	return g.tokenUsage
}