package handler

import (
	"encoding/base64"
	"encoding/json"
	"fmt"
	"net/http"
	"net/url"
	"os"
	"strings"
	"time"

	"cyberstrike-ai/internal/config"

	"github.com/gin-gonic/gin"
	"go.uber.org/zap"
)

type FofaHandler struct {
	cfg    *config.Config
	logger *zap.Logger
	client *http.Client
}

func NewFofaHandler(cfg *config.Config, logger *zap.Logger) *FofaHandler {
	return &FofaHandler{
		cfg:    cfg,
		logger: logger,
		client: &http.Client{Timeout: 30 * time.Second},
	}
}

type fofaSearchRequest struct {
	Query  string `json:"query" binding:"required"`
	Size   int    `json:"size,omitempty"`
	Page   int    `json:"page,omitempty"`
	Fields string `json:"fields,omitempty"`
	Full   bool   `json:"full,omitempty"`
}

type fofaAPIResponse struct {
	Error   bool            `json:"error"`
	ErrMsg  string          `json:"errmsg"`
	Size    int             `json:"size"`
	Page    int             `json:"page"`
	Total   int             `json:"total"`
	Mode    string          `json:"mode"`
	Query   string          `json:"query"`
	Results [][]interface{} `json:"results"`
}

type fofaSearchResponse struct {
	Query        string                   `json:"query"`
	Size         int                      `json:"size"`
	Page         int                      `json:"page"`
	Total        int                      `json:"total"`
	Fields       []string                 `json:"fields"`
	ResultsCount int                      `json:"results_count"`
	Results      []map[string]interface{} `json:"results"`
}

func (h *FofaHandler) resolveCredentials() (email, apiKey string) {
	// 优先环境变量（便于容器部署），其次配置文件
	email = strings.TrimSpace(os.Getenv("FOFA_EMAIL"))
	apiKey = strings.TrimSpace(os.Getenv("FOFA_API_KEY"))
	if email != "" && apiKey != "" {
		return email, apiKey
	}
	if h.cfg != nil {
		if email == "" {
			email = strings.TrimSpace(h.cfg.FOFA.Email)
		}
		if apiKey == "" {
			apiKey = strings.TrimSpace(h.cfg.FOFA.APIKey)
		}
	}
	return email, apiKey
}

func (h *FofaHandler) resolveBaseURL() string {
	if h.cfg != nil {
		if v := strings.TrimSpace(h.cfg.FOFA.BaseURL); v != "" {
			return v
		}
	}
	return "https://fofa.info/api/v1/search/all"
}

// Search FOFA 查询（后端代理，避免前端暴露 key）
func (h *FofaHandler) Search(c *gin.Context) {
	var req fofaSearchRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "无效的请求参数: " + err.Error()})
		return
	}

	req.Query = strings.TrimSpace(req.Query)
	if req.Query == "" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "query 不能为空"})
		return
	}
	if req.Size <= 0 {
		req.Size = 100
	}
	if req.Page <= 0 {
		req.Page = 1
	}
	// FOFA 接口 size 上限和账户权限相关，这里只做一个合理的保护
	if req.Size > 10000 {
		req.Size = 10000
	}
	if req.Fields == "" {
		req.Fields = "host,ip,port,domain,title,protocol,country,province,city,server"
	}

	email, apiKey := h.resolveCredentials()
	if email == "" || apiKey == "" {
		c.JSON(http.StatusBadRequest, gin.H{
			"error":   "FOFA 未配置：请在系统设置中填写 FOFA Email/API Key，或设置环境变量 FOFA_EMAIL/FOFA_API_KEY",
			"need":    []string{"fofa.email", "fofa.api_key"},
			"env_key": []string{"FOFA_EMAIL", "FOFA_API_KEY"},
		})
		return
	}

	baseURL := h.resolveBaseURL()
	qb64 := base64.StdEncoding.EncodeToString([]byte(req.Query))

	u, err := url.Parse(baseURL)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "FOFA base_url 无效: " + err.Error()})
		return
	}

	params := u.Query()
	params.Set("email", email)
	params.Set("key", apiKey)
	params.Set("qbase64", qb64)
	params.Set("size", fmt.Sprintf("%d", req.Size))
	params.Set("page", fmt.Sprintf("%d", req.Page))
	params.Set("fields", strings.TrimSpace(req.Fields))
	if req.Full {
		params.Set("full", "true")
	} else {
		// 明确传 false，便于排查
		params.Set("full", "false")
	}
	u.RawQuery = params.Encode()

	httpReq, err := http.NewRequestWithContext(c.Request.Context(), http.MethodGet, u.String(), nil)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "创建请求失败: " + err.Error()})
		return
	}

	resp, err := h.client.Do(httpReq)
	if err != nil {
		c.JSON(http.StatusBadGateway, gin.H{"error": "请求 FOFA 失败: " + err.Error()})
		return
	}
	defer resp.Body.Close()

	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
		c.JSON(http.StatusBadGateway, gin.H{"error": fmt.Sprintf("FOFA 返回非 2xx: %d", resp.StatusCode)})
		return
	}

	var apiResp fofaAPIResponse
	if err := json.NewDecoder(resp.Body).Decode(&apiResp); err != nil {
		c.JSON(http.StatusBadGateway, gin.H{"error": "解析 FOFA 响应失败: " + err.Error()})
		return
	}
	if apiResp.Error {
		msg := strings.TrimSpace(apiResp.ErrMsg)
		if msg == "" {
			msg = "FOFA 返回错误"
		}
		c.JSON(http.StatusBadGateway, gin.H{"error": msg})
		return
	}

	fields := splitAndCleanCSV(req.Fields)
	results := make([]map[string]interface{}, 0, len(apiResp.Results))
	for _, row := range apiResp.Results {
		item := make(map[string]interface{}, len(fields))
		for i, f := range fields {
			if i < len(row) {
				item[f] = row[i]
			} else {
				item[f] = nil
			}
		}
		results = append(results, item)
	}

	c.JSON(http.StatusOK, fofaSearchResponse{
		Query:        req.Query,
		Size:         apiResp.Size,
		Page:         apiResp.Page,
		Total:        apiResp.Total,
		Fields:       fields,
		ResultsCount: len(results),
		Results:      results,
	})
}

func splitAndCleanCSV(s string) []string {
	parts := strings.Split(s, ",")
	out := make([]string, 0, len(parts))
	seen := make(map[string]struct{}, len(parts))
	for _, p := range parts {
		v := strings.TrimSpace(p)
		if v == "" {
			continue
		}
		if _, ok := seen[v]; ok {
			continue
		}
		seen[v] = struct{}{}
		out = append(out, v)
	}
	return out
}