package ai

import (
	"context"
	"fmt"

	"gitea.oblak.solutions/dimitar/gitFlow/internal/config"
	"gitea.oblak.solutions/dimitar/gitFlow/internal/httpclient"
	"gitea.oblak.solutions/dimitar/gitFlow/pkg/status"
)

const (
	defaultAnthropicBaseURL = "https://api.anthropic.com/v1"
	anthropicVersion        = "2023-06-01"
)

// AnthropicProvider talks to the Anthropic Messages API.
type AnthropicProvider struct {
	model   string
	baseURL string
	apiKey  string
	http    *httpclient.Client
}

// NewAnthropic builds an Anthropic provider. base_url and model fall back
// to sensible defaults when unset in the configuration.
func NewAnthropic(cfg config.AIConfig, apiKey string) *AnthropicProvider {
	baseURL := cfg.BaseURL
	if baseURL == "" {
		baseURL = defaultAnthropicBaseURL
	}
	model := cfg.Model
	if model == "" {
		model = "claude-3-5-haiku-latest"
	}
	return &AnthropicProvider{model: model, baseURL: baseURL, apiKey: apiKey, http: httpclient.New()}
}

// Name implements Provider.
func (p *AnthropicProvider) Name() string { return "anthropic" }

type anthropicRequest struct {
	Model     string        `json:"model"`
	MaxTokens int           `json:"max_tokens"`
	System    string        `json:"system"`
	Messages  []chatMessage `json:"messages"`
}

type anthropicResponse struct {
	Content []struct {
		Type string `json:"type"`
		Text string `json:"text"`
	} `json:"content"`
	Error *struct {
		Message string `json:"message"`
	} `json:"error"`
}

// Suggest implements Provider.
func (p *AnthropicProvider) Suggest(ctx context.Context, result status.ScanResult) ([]Suggestion, error) {
	req := anthropicRequest{
		Model:     p.model,
		MaxTokens: 1024,
		System:    "You are gitflow, a concise Git repository health assistant. You reply with JSON only.",
		Messages:  []chatMessage{{Role: "user", Content: BuildPrompt(result)}},
	}

	var resp anthropicResponse
	err := p.http.PostJSON(ctx, p.baseURL+"/messages",
		map[string]string{"x-api-key": p.apiKey, "anthropic-version": anthropicVersion}, req, &resp)
	if err != nil {
		return nil, err
	}
	if resp.Error != nil {
		return nil, fmt.Errorf("ai: anthropic: %s", resp.Error.Message)
	}
	for _, c := range resp.Content {
		if c.Type == "text" && c.Text != "" {
			return parseSuggestions(c.Text)
		}
	}
	return nil, fmt.Errorf("ai: anthropic: empty response")
}