package openrouter

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"log"
	"net/http"
	"time"
)

type OpenRouterProvider struct {
	// Endpoint string
	Token string
	Model string // "openai/gpt-oss-20b:free"
}

type Message struct {
	Role    string `json:"role"` // "system" | "user" | "assistant"
	Content string `json:"content"`
}

type ChatCompletionRequest struct {
	Model       string          `json:"model"`
	Messages    []Message       `json:"messages"`
	Temperature *float64        `json:"temperature,omitempty"`
	MaxTokens   *int            `json:"max_tokens,omitempty"`
	TopP        *float64        `json:"top_p,omitempty"`
	Stop        json.RawMessage `json:"stop,omitempty"` // string or []string; keep flexible
	Provider    struct {
		Sort string `json:"sort,omitempty"`
	} `json:"provider,omitempty"`
	
}

type ChatCompletionResponse struct {
	ID      string `json:"id"`
	Choices []struct {
		Index   int `json:"index"`
		Message struct {
			Role    string `json:"role"`
			Content string `json:"content"`
		} `json:"message"`
		FinishReason string `json:"finish_reason"`
	} `json:"choices"`
}

func (p OpenRouterProvider) Complete(ctx context.Context, prompt string) (string, error) {
	req := ChatCompletionRequest{
		Model: p.Model,
		Messages: []Message{
			{
				Role:    "user",
				Content: prompt,
			},
		},
		Provider: struct {
			Sort string `json:"sort,omitempty"`
		}{
			Sort: "throughput",
		},
	}

	httpClient := http.Client{Timeout: 10 * time.Second}
	body, err := json.Marshal(req)
	if err != nil {
		return "", err
	}

	httpReq, err := http.NewRequestWithContext(ctx, "POST", "https://openrouter.ai/api/v1/chat/completions", bytes.NewReader(body))
	if err != nil {
		return "", err
	}

	httpReq.Header.Set("Authorization", fmt.Sprintf("Bearer %v", p.Token))
	httpReq.Header.Set("Content-Type", "application/json")

	resp, err := httpClient.Do(httpReq)
	if err != nil {
		return "", err
	}
	defer resp.Body.Close()

	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
		// You may want to decode OpenRouter's error JSON here for better messages
		return "", fmt.Errorf("openrouter status %d", resp.StatusCode)
	}

	var out ChatCompletionResponse
	if err := json.NewDecoder(resp.Body).Decode(&out); err != nil {
		log.Println(err)
		log.Println(out)
		return "", err
	}
	return out.Choices[0].Message.Content, nil
}