package commands

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

type SetAcmeRecordArgs struct {
	APIToken    string
	ZoneID      string
	RecordName  string
	RecordValue string
}

type cfDNSRecordRequest struct {
	Type    string `json:"type"`
	Name    string `json:"name"`
	Content string `json:"content"`
	TTL     int    `json:"ttl"`
}

type cfDNSRecord struct {
	ID      string `json:"id"`
	Name    string `json:"name"`
	Content string `json:"content"`
}

type cfDNSRecordResponse struct {
	Success bool `json:"success"`
	Errors  []struct {
		Message string `json:"message"`
	} `json:"errors"`
	Result cfDNSRecord `json:"result"`
}

type cfDNSListResponse struct {
	Success bool `json:"success"`
	Errors  []struct {
		Message string `json:"message"`
	} `json:"errors"`
	Result []cfDNSRecord `json:"result"`
}

func cfRequest(method, url, token string, body []byte) (*http.Response, error) {
	req, err := http.NewRequest(method, url, bytes.NewReader(body))
	if err != nil {
		return nil, fmt.Errorf("error creating request: %w", err)
	}
	req.Header.Set("Authorization", "Bearer "+token)
	req.Header.Set("Content-Type", "application/json")
	return (&http.Client{}).Do(req)
}

func SetAcmeRecord(args SetAcmeRecordArgs, stdout, stderr io.Writer) error {
	listURL := fmt.Sprintf("https://api.cloudflare.com/client/v4/zones/%s/dns_records?type=TXT&name=%s", args.ZoneID, args.RecordName)
	resp, err := cfRequest("GET", listURL, args.APIToken, nil)
	if err != nil {
		return fmt.Errorf("error listing DNS records: %w", err)
	}
	defer resp.Body.Close()

	var listResult cfDNSListResponse
	if err := json.NewDecoder(resp.Body).Decode(&listResult); err != nil {
		return fmt.Errorf("error decoding list response: %w", err)
	}
	if !listResult.Success {
		msg := "Cloudflare API error:"
		for _, e := range listResult.Errors {
			msg += " " + e.Message
		}
		return fmt.Errorf("%s", msg)
	}

	record := cfDNSRecordRequest{
		Type:    "TXT",
		Name:    args.RecordName,
		Content: args.RecordValue,
		TTL:     1,
	}
	body, err := json.Marshal(record)
	if err != nil {
		return fmt.Errorf("error marshaling request: %w", err)
	}

	var method, recordURL, action string
	if len(listResult.Result) > 0 {
		method = "PUT"
		recordURL = fmt.Sprintf("https://api.cloudflare.com/client/v4/zones/%s/dns_records/%s", args.ZoneID, listResult.Result[0].ID)
		action = "Updated"
	} else {
		method = "POST"
		recordURL = fmt.Sprintf("https://api.cloudflare.com/client/v4/zones/%s/dns_records", args.ZoneID)
		action = "Created"
	}

	resp2, err := cfRequest(method, recordURL, args.APIToken, body)
	if err != nil {
		return fmt.Errorf("error calling Cloudflare API: %w", err)
	}
	defer resp2.Body.Close()

	var result cfDNSRecordResponse
	if err := json.NewDecoder(resp2.Body).Decode(&result); err != nil {
		return fmt.Errorf("error decoding response: %w", err)
	}
	if !result.Success {
		msg := "Cloudflare API error:"
		for _, e := range result.Errors {
			msg += " " + e.Message
		}
		return fmt.Errorf("%s", msg)
	}

	fmt.Fprintf(stdout, "%s TXT record:\n  ID: %s\n  Name: %s\n  Content: %s\n",
		action, result.Result.ID, result.Result.Name, result.Result.Content)
	return nil
}