package main

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

// GiteeClient Gitee API 客户端
type GiteeClient struct {
	AccessToken string
	Owner       string
	Repo        string
	BaseURL     string
}

// NewGiteeClient 创建新的 Gitee 客户端
func NewGiteeClient(accessToken, owner, repo string) *GiteeClient {
	return &GiteeClient{
		AccessToken: accessToken,
		Owner:       owner,
		Repo:        repo,
		BaseURL:     "https://gitee.com/api/v5",
	}
}

// User 用户信息
type User struct {
	ID           int    `json:"id"`
	Login        string `json:"login"`
	Name         string `json:"name"`
	AvatarURL    string `json:"avatar_url"`
	HTMLURL      string `json:"html_url"`
	FollowersURL string `json:"followers_url"`
	FollowingURL string `json:"following_url"`
	Type         string `json:"type"`
}

// Issue Issue 结构（帖子）
type Issue struct {
	ID            int       `json:"id"`
	URL           string    `json:"url"`
	RepositoryURL string    `json:"repository_url"`
	LabelsURL     string    `json:"labels_url"`
	CommentsURL   string    `json:"comments_url"`
	HTMLURL       string    `json:"html_url"`
	ParentURL     *string   `json:"parent_url"`
	Number        string    `json:"number"`
	ParentID      int       `json:"parent_id"`
	Depth         int       `json:"depth"`
	State         string    `json:"state"`
	Title         string    `json:"title"`
	Body          string    `json:"body"`
	User          User      `json:"user"`
	Labels        []Label   `json:"labels"`
	CreatedAt     time.Time `json:"created_at"`
	UpdatedAt     time.Time `json:"updated_at"`
}

// Label 标签
type Label struct {
	ID    int    `json:"id"`
	Name  string `json:"name"`
	Color string `json:"color"`
}

// Comment 评论结构（回帖）
type Comment struct {
	ID        int       `json:"id"`
	Body      string    `json:"body"`
	User      User      `json:"user"`
	Source    *string   `json:"source"`
	Target    Target    `json:"target"`
	CreatedAt time.Time `json:"created_at"`
	UpdatedAt time.Time `json:"updated_at"`
}

// Target 评论目标
type Target struct {
	Issue       *IssueTarget `json:"issue"`
	PullRequest *string      `json:"pull_request"`
}

// IssueTarget Issue 目标信息
type IssueTarget struct {
	ID     int    `json:"id"`
	Title  string `json:"title"`
	Number string `json:"number"`
}

// CreateIssueRequest 创建 Issue 请求
type CreateIssueRequest struct {
	Title        string `json:"title"`
	Body         string `json:"body,omitempty"`
	SecurityHole string `json:"security_hole,omitempty"` // "true" 或 "false"
	Labels       string `json:"labels,omitempty"`        // 逗号分隔的标签
}

// UpdateIssueRequest 更新 Issue 请求
type UpdateIssueRequest struct {
	State  string `json:"state,omitempty"` // "open" 或 "closed"
	Title  string `json:"title,omitempty"`
	Body   string `json:"body,omitempty"`
	Labels string `json:"labels,omitempty"` // 逗号分隔的标签
}

// CreateCommentRequest 创建评论请求
type CreateCommentRequest struct {
	Body string `json:"body"`
}

// ListIssuesOptions 获取 Issues 列表的选项
type ListIssuesOptions struct {
	State     string // "open", "closed", "all"，默认 "open"
	Sort      string // "created", "updated", "comments"，默认 "created"
	Direction string // "asc", "desc"，默认 "desc"
	Page      int    // 页码，默认 1
	PerPage   int    // 每页数量，默认 20
}

// ListCommentsOptions 获取评论列表的选项
type ListCommentsOptions struct {
	Page    int    // 页码，默认 1
	PerPage int    // 每页数量，默认 20
	Order   string // "asc", "desc"，默认 "asc"
}

// CreateIssue 创建 Issue（发帖）
func (c *GiteeClient) CreateIssue(req CreateIssueRequest) (*Issue, error) {
	apiURL := fmt.Sprintf("%s/repos/%s/issues", c.BaseURL, c.Owner)

	data := map[string]string{
		"access_token":  c.AccessToken,
		"repo":          c.Repo,
		"title":         req.Title,
		"security_hole": "false",
	}

	if req.Body != "" {
		data["body"] = req.Body
	}
	if req.SecurityHole != "" {
		data["security_hole"] = req.SecurityHole
	}
	if req.Labels != "" {
		data["labels"] = req.Labels
	}

	jsonData, err := json.Marshal(data)
	if err != nil {
		return nil, fmt.Errorf("序列化请求数据失败: %w", err)
	}

	resp, err := http.Post(apiURL, "application/json;charset=UTF-8", bytes.NewBuffer(jsonData))
	if err != nil {
		return nil, fmt.Errorf("请求失败: %w", err)
	}
	defer resp.Body.Close()

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, fmt.Errorf("读取响应失败: %w", err)
	}

	if resp.StatusCode != http.StatusCreated && resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("API 返回错误状态码 %d: %s", resp.StatusCode, string(body))
	}

	var issue Issue
	if err := json.Unmarshal(body, &issue); err != nil {
		return nil, fmt.Errorf("解析响应失败: %w", err)
	}

	return &issue, nil
}

// UpdateIssue 更新 Issue（更新帖子）
func (c *GiteeClient) UpdateIssue(number string, req UpdateIssueRequest) (*Issue, error) {
	apiURL := fmt.Sprintf("%s/repos/%s/issues/%s", c.BaseURL, c.Owner, number)

	data := map[string]string{
		"access_token": c.AccessToken,
		"repo":         c.Repo,
	}

	if req.State != "" {
		data["state"] = req.State
	}
	if req.Title != "" {
		data["title"] = req.Title
	}
	if req.Body != "" {
		data["body"] = req.Body
	}
	if req.Labels != "" {
		data["labels"] = req.Labels
	}

	jsonData, err := json.Marshal(data)
	if err != nil {
		return nil, fmt.Errorf("序列化请求数据失败: %w", err)
	}

	client := &http.Client{}
	httpReq, err := http.NewRequest(http.MethodPatch, apiURL, bytes.NewBuffer(jsonData))
	if err != nil {
		return nil, fmt.Errorf("创建请求失败: %w", err)
	}
	httpReq.Header.Set("Content-Type", "application/json;charset=UTF-8")

	resp, err := client.Do(httpReq)
	if err != nil {
		return nil, fmt.Errorf("请求失败: %w", err)
	}
	defer resp.Body.Close()

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, fmt.Errorf("读取响应失败: %w", err)
	}

	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("API 返回错误状态码 %d: %s", resp.StatusCode, string(body))
	}

	var issue Issue
	if err := json.Unmarshal(body, &issue); err != nil {
		return nil, fmt.Errorf("解析响应失败: %w", err)
	}

	return &issue, nil
}

// ListIssues 获取仓库的所有 Issues（获取帖子列表）
func (c *GiteeClient) ListIssues(opts *ListIssuesOptions) ([]Issue, error) {
	apiURL := fmt.Sprintf("%s/repos/%s/%s/issues", c.BaseURL, c.Owner, c.Repo)

	// 构建查询参数
	params := url.Values{}
	params.Add("access_token", c.AccessToken)

	if opts != nil {
		if opts.State != "" {
			params.Add("state", opts.State)
		} else {
			params.Add("state", "open")
		}

		if opts.Sort != "" {
			params.Add("sort", opts.Sort)
		} else {
			params.Add("sort", "created")
		}

		if opts.Direction != "" {
			params.Add("direction", opts.Direction)
		} else {
			params.Add("direction", "desc")
		}

		if opts.Page > 0 {
			params.Add("page", fmt.Sprintf("%d", opts.Page))
		} else {
			params.Add("page", "1")
		}

		if opts.PerPage > 0 {
			params.Add("per_page", fmt.Sprintf("%d", opts.PerPage))
		} else {
			params.Add("per_page", "20")
		}
	} else {
		// 默认参数
		params.Add("state", "open")
		params.Add("sort", "created")
		params.Add("direction", "desc")
		params.Add("page", "1")
		params.Add("per_page", "20")
	}

	fullURL := fmt.Sprintf("%s?%s", apiURL, params.Encode())

	resp, err := http.Get(fullURL)
	if err != nil {
		return nil, fmt.Errorf("请求失败: %w", err)
	}
	defer resp.Body.Close()

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, fmt.Errorf("读取响应失败: %w", err)
	}

	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("API 返回错误状态码 %d: %s", resp.StatusCode, string(body))
	}

	var issues []Issue
	if err := json.Unmarshal(body, &issues); err != nil {
		return nil, fmt.Errorf("解析响应失败: %w", err)
	}

	return issues, nil
}

// CreateComment 创建某个 Issue 的评论（发回帖）
func (c *GiteeClient) CreateComment(issueNumber string, req CreateCommentRequest) (*Comment, error) {
	apiURL := fmt.Sprintf("%s/repos/%s/%s/issues/%s/comments", c.BaseURL, c.Owner, c.Repo, issueNumber)

	data := map[string]string{
		"access_token": c.AccessToken,
		"body":         req.Body,
	}

	jsonData, err := json.Marshal(data)
	if err != nil {
		return nil, fmt.Errorf("序列化请求数据失败: %w", err)
	}

	resp, err := http.Post(apiURL, "application/json;charset=UTF-8", bytes.NewBuffer(jsonData))
	if err != nil {
		return nil, fmt.Errorf("请求失败: %w", err)
	}
	defer resp.Body.Close()

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, fmt.Errorf("读取响应失败: %w", err)
	}

	if resp.StatusCode != http.StatusCreated && resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("API 返回错误状态码 %d: %s", resp.StatusCode, string(body))
	}

	var comment Comment
	if err := json.Unmarshal(body, &comment); err != nil {
		return nil, fmt.Errorf("解析响应失败: %w", err)
	}

	return &comment, nil
}

// ListComments 获取仓库某个 Issue 的所有评论（获取帖子详情）
func (c *GiteeClient) ListComments(issueNumber string, opts *ListCommentsOptions) ([]Comment, error) {
	apiURL := fmt.Sprintf("%s/repos/%s/%s/issues/%s/comments", c.BaseURL, c.Owner, c.Repo, issueNumber)

	// 构建查询参数
	params := url.Values{}
	params.Add("access_token", c.AccessToken)

	if opts != nil {
		if opts.Page > 0 {
			params.Add("page", fmt.Sprintf("%d", opts.Page))
		} else {
			params.Add("page", "1")
		}

		if opts.PerPage > 0 {
			params.Add("per_page", fmt.Sprintf("%d", opts.PerPage))
		} else {
			params.Add("per_page", "20")
		}

		if opts.Order != "" {
			params.Add("order", opts.Order)
		} else {
			params.Add("order", "asc")
		}
	} else {
		// 默认参数
		params.Add("page", "1")
		params.Add("per_page", "20")
		params.Add("order", "asc")
	}

	fullURL := fmt.Sprintf("%s?%s", apiURL, params.Encode())

	resp, err := http.Get(fullURL)
	if err != nil {
		return nil, fmt.Errorf("请求失败: %w", err)
	}
	defer resp.Body.Close()

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, fmt.Errorf("读取响应失败: %w", err)
	}

	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("API 返回错误状态码 %d: %s", resp.StatusCode, string(body))
	}

	var comments []Comment
	if err := json.Unmarshal(body, &comments); err != nil {
		return nil, fmt.Errorf("解析响应失败: %w", err)
	}

	return comments, nil
}