package providers

import (
	"context"
	"encoding/json"
	"fmt"
	"strings"
	"time"

	"github.com/go-resty/resty/v2"
	"gophergate/internal/config"
	"gophergate/internal/models"
)

type MoonshotProvider struct {
	client *resty.Client
	config config.MoonshotConfig
	apiKey string
}

func NewMoonshotProvider(cfg config.MoonshotConfig, apiKey string) *MoonshotProvider {
	return &MoonshotProvider{
		client: resty.New().SetTimeout(10 * time.Minute),
		config: cfg,
		apiKey: strings.TrimSpace(apiKey),
	}
}

func (p *MoonshotProvider) Name() string {
	return "moonshot"
}

func (p *MoonshotProvider) ChatCompletion(ctx context.Context, req *models.UnifiedRequest) (*models.ChatCompletionResponse, error) {
	messagesJSON, err := MessagesToOpenAIJSON(req.Messages)
	if err != nil {
		return nil, fmt.Errorf("failed to convert messages: %w", err)
	}

	body := BuildOpenAIBody(req, messagesJSON, false)
	if strings.Contains(strings.ToLower(req.Model), "kimi-k2.5") {
		if maxTokens, ok := body["max_tokens"]; ok {
			delete(body, "max_tokens")
			body["max_completion_tokens"] = maxTokens
		}
	}

	baseURL := strings.TrimRight(p.config.BaseURL, "/")

	resp, err := p.client.R().
		SetContext(ctx).
		SetHeader("Authorization", "Bearer "+p.apiKey).
		SetHeader("Content-Type", "application/json").
		SetHeader("Accept", "application/json").
		SetBody(body).
		Post(fmt.Sprintf("%s/chat/completions", baseURL))

	if err != nil {
		return nil, fmt.Errorf("request failed: %w", err)
	}

	if !resp.IsSuccess() {
		return nil, fmt.Errorf("Moonshot API error (%d): %s", resp.StatusCode(), resp.String())
	}

	var respJSON map[string]interface{}
	if err := json.Unmarshal(resp.Body(), &respJSON); err != nil {
		return nil, fmt.Errorf("failed to parse response: %w", err)
	}

	return ParseOpenAIResponse(respJSON, req.Model)
}

func (p *MoonshotProvider) ChatCompletionStream(ctx context.Context, req *models.UnifiedRequest) (<-chan *models.ChatCompletionStreamResponse, error) {
	messagesJSON, err := MessagesToOpenAIJSON(req.Messages)
	if err != nil {
		return nil, fmt.Errorf("failed to convert messages: %w", err)
	}

	body := BuildOpenAIBody(req, messagesJSON, true)
	if strings.Contains(strings.ToLower(req.Model), "kimi-k2.5") {
		if maxTokens, ok := body["max_tokens"]; ok {
			delete(body, "max_tokens")
			body["max_completion_tokens"] = maxTokens
		}
	}

	baseURL := strings.TrimRight(p.config.BaseURL, "/")

	resp, err := p.client.R().
		SetContext(ctx).
		SetHeader("Authorization", "Bearer "+p.apiKey).
		SetHeader("Content-Type", "application/json").
		SetHeader("Accept", "text/event-stream").
		SetBody(body).
		SetDoNotParseResponse(true).
		Post(fmt.Sprintf("%s/chat/completions", baseURL))

	if err != nil {
		return nil, fmt.Errorf("request failed: %w", err)
	}

	if !resp.IsSuccess() {
		return nil, fmt.Errorf("Moonshot API error (%d): %s", resp.StatusCode(), resp.String())
	}

	ch := make(chan *models.ChatCompletionStreamResponse)
	go func() {
		defer close(ch)
		if err := StreamOpenAI(resp.RawBody(), ch); err != nil {
			fmt.Printf("Moonshot Stream error: %v\n", err)
		}
	}()

	return ch, nil
}

func (p *MoonshotProvider) ImageGeneration(ctx context.Context, req *models.ImageGenerationRequest) (*models.ImageGenerationResponse, error) {
	return nil, fmt.Errorf("moonshot does not support image generation")
}

func (p *MoonshotProvider) Responses(ctx context.Context, req *models.ResponsesRequest) (*models.ResponsesResponse, error) {
	return nil, fmt.Errorf("responses API not supported by moonshot")
}

func (p *MoonshotProvider) ResponsesStream(ctx context.Context, req *models.ResponsesRequest) (<-chan *models.ResponsesStreamChunk, error) {
	return nil, fmt.Errorf("responses API not supported by moonshot")
}
