package gitea

import (
	"context"
	"encoding/json"
	"fmt"
	"net/http"
	"time"

	"github.com/rs/zerolog"

	"github.com/vincentc-afk/gitea-notification-hub/internal/config"
)

// GiteaUser represents a user from Gitea API
type GiteaUser struct {
	ID        int64  `json:"id"`
	Login     string `json:"login"`
	FullName  string `json:"full_name"`
	Email     string `json:"email"`
	AvatarURL string `json:"avatar_url"`
}

// Provider implements email lookup via Gitea API
type Provider struct {
	baseURL    string
	token      string
	httpClient *http.Client
	logger     zerolog.Logger
}

// New creates a new Gitea API provider
func New(cfg *config.GiteaConfig, logger zerolog.Logger) *Provider {
	return &Provider{
		baseURL: cfg.URL,
		token:   cfg.Token,
		httpClient: &http.Client{
			Timeout: 10 * time.Second,
		},
		logger: logger.With().Str("component", "gitea-provider").Logger(),
	}
}

// LookupEmail fetches the real email for a Gitea username via API
func (p *Provider) LookupEmail(ctx context.Context, username string) (string, error) {
	url := fmt.Sprintf("%s/api/v1/users/%s", p.baseURL, username)

	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
	if err != nil {
		return "", fmt.Errorf("creating request: %w", err)
	}

	// Add authorization header if token is provided
	if p.token != "" {
		req.Header.Set("Authorization", "token "+p.token)
	}
	req.Header.Set("Accept", "application/json")

	resp, err := p.httpClient.Do(req)
	if err != nil {
		return "", fmt.Errorf("fetching user from Gitea: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode == http.StatusNotFound {
		return "", fmt.Errorf("user %s not found in Gitea", username)
	}

	if resp.StatusCode != http.StatusOK {
		return "", fmt.Errorf("Gitea API returned status %d", resp.StatusCode)
	}

	var user GiteaUser
	if err := json.NewDecoder(resp.Body).Decode(&user); err != nil {
		return "", fmt.Errorf("decoding Gitea response: %w", err)
	}

	if user.Email == "" {
		return "", fmt.Errorf("user %s has no email in Gitea", username)
	}

	p.logger.Debug().
		Str("username", username).
		Str("email", user.Email).
		Str("full_name", user.FullName).
		Msg("found user email via Gitea API")

	return user.Email, nil
}

// GetUser fetches full user info from Gitea API
func (p *Provider) GetUser(ctx context.Context, username string) (*GiteaUser, error) {
	url := fmt.Sprintf("%s/api/v1/users/%s", p.baseURL, username)

	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
	if err != nil {
		return nil, fmt.Errorf("creating request: %w", err)
	}

	if p.token != "" {
		req.Header.Set("Authorization", "token "+p.token)
	}
	req.Header.Set("Accept", "application/json")

	resp, err := p.httpClient.Do(req)
	if err != nil {
		return nil, fmt.Errorf("fetching user from Gitea: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode == http.StatusNotFound {
		return nil, fmt.Errorf("user %s not found in Gitea", username)
	}

	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("Gitea API returned status %d", resp.StatusCode)
	}

	var user GiteaUser
	if err := json.NewDecoder(resp.Body).Decode(&user); err != nil {
		return nil, fmt.Errorf("decoding Gitea response: %w", err)
	}

	return &user, nil
}