package gitea

import (
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"strings"
	"time"
)

type Client struct {
	BaseURL string
	Token   string
	Client  *http.Client
}

func NewClient(baseURL, token string) *Client {
	baseURL = strings.TrimRight(baseURL, "/")
	
	if !strings.HasPrefix(baseURL, "http://") && !strings.HasPrefix(baseURL, "https://") {
		baseURL = "https://" + baseURL
	}
	
	if strings.HasSuffix(baseURL, "/api/v1") {
		baseURL = strings.TrimSuffix(baseURL, "/api/v1")
	}
	if strings.HasSuffix(baseURL, "/api") {
		baseURL = strings.TrimSuffix(baseURL, "/api")
	}
	
	return &Client{
		BaseURL: baseURL,
		Token:   token,
		Client:  &http.Client{Timeout: 60 * time.Second},
	}
}

type GiteaRepo struct {
	ID       int64    `json:"id"`
	Name     string   `json:"name"`
	FullName string   `json:"full_name"`
	HTMLURL  string   `json:"html_url"`
	Language string   `json:"language"`
	Topics   []string `json:"topics"`
}

type GiteaCommit struct {
	SHA    string `json:"sha"`
	Commit struct {
		Author struct {
			Name  string    `json:"name"`
			Email string    `json:"email"`
			Date  time.Time `json:"date"`
		} `json:"author"`
		Message string `json:"message"`
	} `json:"commit"`
}

// do makes an authenticated HTTP request to Gitea API
func (c *Client) do(method, path string) ([]byte, error) {
	url := fmt.Sprintf("%s/api/v1%s", c.BaseURL, path)
	
	req, err := http.NewRequest(method, url, nil)
	if err != nil {
		return nil, fmt.Errorf("failed to create request for %s: %w", url, err)
	}

	req.Header.Set("Authorization", fmt.Sprintf("token %s", c.Token))
	req.Header.Set("Accept", "application/json")
	req.Header.Set("User-Agent", "gitea-wrapped/1.0")

	resp, err := c.Client.Do(req)
	if err != nil {
		return nil, fmt.Errorf("API request failed (%s %s): %w", method, url, err)
	}
	defer resp.Body.Close()

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, fmt.Errorf("failed to read response: %w", err)
	}

	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
		errMsg := string(body)
		if len(errMsg) > 500 {
			errMsg = errMsg[:500]
		}
		return nil, fmt.Errorf("API error %d: %s", resp.StatusCode, errMsg)
	}

	return body, nil
}

func (c *Client) GetUserRepos() ([]GiteaRepo, error) {
	var repos []GiteaRepo
	page := 1
	pageSize := 50
	maxPages := 100 // Safety limit to prevent infinite loops

	for page <= maxPages {
		path := fmt.Sprintf("/user/repos?page=%d&limit=%d", page, pageSize)
		body, err := c.do("GET", path)
		if err != nil {
			if len(repos) > 0 {
				return repos, nil
			}
			return nil, err
		}

		var pageRepos []GiteaRepo
		if err := json.Unmarshal(body, &pageRepos); err != nil {
			return nil, err
		}

		if len(pageRepos) == 0 {
			break
		}

		repos = append(repos, pageRepos...)

		if len(pageRepos) < pageSize {
			break
		}

		page++
	}

	return repos, nil
}

func (c *Client) GetRepoCommits(owner, repo string) ([]GiteaCommit, error) {
	var commits []GiteaCommit
	page := 1
	pageSize := 50
	maxPages := 1000 // Safety limit to prevent infinite loops

	for page <= maxPages {
		path := fmt.Sprintf("/repos/%s/%s/commits?page=%d&limit=%d", owner, repo, page, pageSize)
		body, err := c.do("GET", path)
		if err != nil {
			if len(commits) > 0 {
				return commits, nil
			}
			return nil, err
		}

		var pageCommits []GiteaCommit
		if err := json.Unmarshal(body, &pageCommits); err != nil {
			return nil, err
		}

		if len(pageCommits) == 0 {
			break
		}

		commits = append(commits, pageCommits...)

		if len(pageCommits) < pageSize {
			break
		}

		page++
	}

	return commits, nil
}

func (c *Client) TestConnection() error {
	_, err := c.do("GET", "/user")
	if err != nil {
		return err
	}
	return nil
}