package ai

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

type anthropicProvider struct {
	apiKey string
	model  string
	client *http.Client
}

func newAnthropic(apiKey, model string) *anthropicProvider {
	if model == "" {
		model = "claude-sonnet-4-6"
	}
	return &anthropicProvider{
		apiKey: apiKey,
		model:  model,
		client: &http.Client{},
	}
}

func (p *anthropicProvider) Name() string { return "anthropic" }

func (p *anthropicProvider) Summarize(ctx context.Context, prompt string) (string, error) {
	body := map[string]interface{}{
		"model":      p.model,
		"max_tokens": 4096,
		"messages": []map[string]string{
			{"role": "user", "content": prompt},
		},
	}
	b, _ := json.Marshal(body)
	req, err := http.NewRequestWithContext(ctx, http.MethodPost, "https://api.anthropic.com/v1/messages", bytes.NewReader(b))
	if err != nil {
		return "", err
	}
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("x-api-key", p.apiKey)
	req.Header.Set("anthropic-version", "2023-06-01")

	resp, err := p.client.Do(req)
	if err != nil {
		return "", err
	}
	defer resp.Body.Close()

	raw, _ := io.ReadAll(resp.Body)
	if resp.StatusCode != http.StatusOK {
		return "", fmt.Errorf("anthropic API error %d: %s", resp.StatusCode, raw)
	}

	var result struct {
		Content []struct {
			Text string `json:"text"`
		} `json:"content"`
	}
	if err := json.Unmarshal(raw, &result); err != nil {
		return "", err
	}
	if len(result.Content) == 0 {
		return "", nil
	}
	return result.Content[0].Text, nil
}

func (p *anthropicProvider) ListModels(_ context.Context) ([]string, error) {
	return []string{
		"claude-opus-4-7",
		"claude-sonnet-4-6",
		"claude-haiku-4-5-20251001",
	}, nil
}