// Package intelx logic
package intelx

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"time"

	jsoniter "github.com/json-iterator/go"

	"github.com/projectdiscovery/subfinder/v2/pkg/subscraping"
)

type searchResponseType struct {
	ID     string `json:"id"`
	Status int    `json:"status"`
}

type selectorType struct {
	Selectvalue string `json:"selectorvalue"`
}

type searchResultType struct {
	Selectors []selectorType `json:"selectors"`
	Status    int            `json:"status"`
}

type requestBody struct {
	Term       string
	Maxresults int
	Media      int
	Target     int
	Terminate  []int
	Timeout    int
}

// Source is the passive scraping agent
type Source struct {
	apiKeys   []apiKey
	timeTaken time.Duration
	errors    int
	results   int
	requests  int
	skipped   bool
}

type apiKey struct {
	host string
	key  string
}

// Run function returns all subdomains found with the service
func (s *Source) Run(ctx context.Context, domain string, session *subscraping.Session) <-chan subscraping.Result {
	results := make(chan subscraping.Result)
	s.errors = 0
	s.results = 0
	s.requests = 0

	go func() {
		defer func(startTime time.Time) {
			s.timeTaken = time.Since(startTime)
			close(results)
		}(time.Now())

		randomApiKey := subscraping.PickRandom(s.apiKeys, s.Name())
		if randomApiKey.host == "" || randomApiKey.key == "" {
			s.skipped = true
			return
		}

		searchURL := fmt.Sprintf("https://%s/phonebook/search?k=%s", randomApiKey.host, randomApiKey.key)
		reqBody := requestBody{
			Term:       domain,
			Maxresults: 100000,
			Media:      0,
			Target:     1,
			Timeout:    20,
		}

		body, err := json.Marshal(reqBody)
		if err != nil {
			results <- subscraping.Result{Source: s.Name(), Type: subscraping.Error, Error: err}
			s.errors++
			return
		}

		s.requests++
		resp, err := session.SimplePost(ctx, searchURL, "application/json", bytes.NewBuffer(body))
		if err != nil {
			results <- subscraping.Result{Source: s.Name(), Type: subscraping.Error, Error: err}
			s.errors++
			session.DiscardHTTPResponse(resp)
			return
		}

		var response searchResponseType
		err = jsoniter.NewDecoder(resp.Body).Decode(&response)
		if err != nil {
			results <- subscraping.Result{Source: s.Name(), Type: subscraping.Error, Error: err}
			s.errors++
			session.DiscardHTTPResponse(resp)
			return
		}

		session.DiscardHTTPResponse(resp)

		resultsURL := fmt.Sprintf("https://%s/phonebook/search/result?k=%s&id=%s&limit=10000", randomApiKey.host, randomApiKey.key, response.ID)
		status := 0
		for status == 0 || status == 3 {
			select {
			case <-ctx.Done():
				return
			default:
			}
			s.requests++
			resp, err = session.Get(ctx, resultsURL, "", nil)
			if err != nil {
				results <- subscraping.Result{Source: s.Name(), Type: subscraping.Error, Error: err}
				s.errors++
				session.DiscardHTTPResponse(resp)
				return
			}
			var response searchResultType
			err = jsoniter.NewDecoder(resp.Body).Decode(&response)
			if err != nil {
				results <- subscraping.Result{Source: s.Name(), Type: subscraping.Error, Error: err}
				s.errors++
				session.DiscardHTTPResponse(resp)
				return
			}
			session.DiscardHTTPResponse(resp)

			status = response.Status
			for _, hostname := range response.Selectors {
				select {
				case <-ctx.Done():
					return
				case results <- subscraping.Result{Source: s.Name(), Type: subscraping.Subdomain, Value: hostname.Selectvalue}:
					s.results++
				}
			}
		}
	}()

	return results
}

// Name returns the name of the source
func (s *Source) Name() string {
	return "intelx"
}

func (s *Source) IsDefault() bool {
	return true
}

func (s *Source) HasRecursiveSupport() bool {
	return false
}

func (s *Source) KeyRequirement() subscraping.KeyRequirement {
	return subscraping.RequiredKey
}

func (s *Source) NeedsKey() bool {
	return s.KeyRequirement() == subscraping.RequiredKey
}

func (s *Source) AddApiKeys(keys []string) {
	s.apiKeys = subscraping.CreateApiKeys(keys, func(k, v string) apiKey {
		return apiKey{k, v}
	})
}

func (s *Source) Statistics() subscraping.Statistics {
	return subscraping.Statistics{
		Errors:    s.errors,
		Results:   s.results,
		Requests:  s.requests,
		TimeTaken: s.timeTaken,
		Skipped:   s.skipped,
	}
}
