package api

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"mime/multipart"
	"net/http"
	"strconv"
	"strings"
)

// ServiceTrade attachment purpose constants with file type restrictions
const (
	// AttachmentPurposeJobPaperwork - PDF documents accepted
	AttachmentPurposeJobPaperwork = 1

	// AttachmentPurposeJobVendorBill - PDF documents accepted
	AttachmentPurposeJobVendorBill = 2

	// AttachmentPurposeJobPicture - Only image files: *.gif, *.jpeg, *.jpg, *.png, *.tif, *.tiff
	AttachmentPurposeJobPicture = 3

	// AttachmentPurposeDeficiencyRepairProposal - PDF documents accepted
	AttachmentPurposeDeficiencyRepairProposal = 5

	// AttachmentPurposeGenericAttachment - PDF documents accepted
	AttachmentPurposeGenericAttachment = 7

	// AttachmentPurposeAvatarImage - Only image files: *.gif, *.jpeg, *.jpg, *.png, *.tif, *.tiff
	AttachmentPurposeAvatarImage = 8

	// AttachmentPurposeImport - Only text files: *.csv, *.txt
	AttachmentPurposeImport = 9

	// AttachmentPurposeBlankPaperwork - PDF documents accepted
	AttachmentPurposeBlankPaperwork = 10

	// AttachmentPurposeWorkAcknowledgement - Only JSON files: *.json
	AttachmentPurposeWorkAcknowledgement = 11

	// AttachmentPurposeLogo - Only image files: *.gif, *.jpeg, *.jpg, *.png, *.tif, *.tiff
	AttachmentPurposeLogo = 12

	// AttachmentPurposeJobInvoice - PDF documents accepted
	AttachmentPurposeJobInvoice = 14
)

// UploadAttachment uploads a file as an attachment to a job
func (s *Session) UploadAttachment(jobID, filename, purpose string, fileContent []byte) (map[string]interface{}, error) {
	url := fmt.Sprintf("%s/attachment", BaseURL)

	// Create a buffer to hold the form data
	var b bytes.Buffer
	w := multipart.NewWriter(&b)

	// Log received values
	log.Printf("Uploading attachment to job ID: %s", jobID)
	log.Printf("Filename: %s", filename)
	log.Printf("Purpose value: '%s'", purpose)
	log.Printf("File content length: %d bytes", len(fileContent))

	// The ServiceTrade API expects the purpose ID as an integer
	purposeStr := strings.TrimSpace(purpose)

	// Try to parse the purpose as an integer, removing any leading zeros first
	purposeStr = strings.TrimLeft(purposeStr, "0")
	if purposeStr == "" {
		purposeStr = "0" // If only zeros were provided
	}

	purposeInt, err := strconv.Atoi(purposeStr)
	if err != nil {
		return nil, fmt.Errorf("invalid purpose value '%s': must be a valid integer: %v", purpose, err)
	}

	log.Printf("Using purpose value: %d for job: %s", purposeInt, jobID)

	// Add the purposeId (attachment type) as an integer
	// NOTE: The API expects "purposeId", not "purpose"
	if err := w.WriteField("purposeId", fmt.Sprintf("%d", purposeInt)); err != nil {
		return nil, fmt.Errorf("error writing purposeId field: %v", err)
	}

	// Add the entityType (3 for Job) and entityId (jobID)
	if err := w.WriteField("entityType", "3"); err != nil { // 3 = Job
		return nil, fmt.Errorf("error writing entityType field: %v", err)
	}

	if err := w.WriteField("entityId", jobID); err != nil {
		return nil, fmt.Errorf("error writing entityId field: %v", err)
	}

	// Ensure we have a file with content to upload
	if len(fileContent) == 0 {
		return nil, fmt.Errorf("no file content provided for upload")
	}

	// Add a description field with the filename for better identification
	if err := w.WriteField("description", filename); err != nil {
		return nil, fmt.Errorf("error writing description field: %v", err)
	}

	// Add the file - make sure we use the real filename with extension for content-type detection
	// The API requires the file extension to determine the content type
	if !strings.Contains(filename, ".") {
		return nil, fmt.Errorf("filename must include an extension (e.g. .pdf, .docx) for API content type detection")
	}

	fw, err := w.CreateFormFile("uploadedFile", filename)
	if err != nil {
		return nil, fmt.Errorf("error creating form file: %v", err)
	}

	bytesWritten, err := io.Copy(fw, bytes.NewReader(fileContent))
	if err != nil {
		return nil, fmt.Errorf("error copying file content: %v", err)
	}
	log.Printf("Wrote %d bytes of file content to the form", bytesWritten)

	// Close the writer
	if err := w.Close(); err != nil {
		return nil, fmt.Errorf("error closing multipart writer: %v", err)
	}

	// Create the request
	req, err := http.NewRequest("POST", url, &b)
	if err != nil {
		return nil, fmt.Errorf("error creating request: %v", err)
	}

	// Set headers
	req.Header.Set("Content-Type", w.FormDataContentType())
	req.Header.Set("Cookie", s.Cookie)

	// Debug information
	log.Printf("Sending request to: %s", url)
	log.Printf("Content-Type: %s", w.FormDataContentType())
	log.Printf("Request body fields: purposeId=%d, entityType=3, entityId=%s, filename=%s", purposeInt, jobID, filename)

	// Send the request
	resp, err := s.Client.Do(req)
	if err != nil {
		return nil, fmt.Errorf("error sending request: %v", err)
	}
	defer resp.Body.Close()

	// Read the response
	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, fmt.Errorf("error reading response body: %v", err)
	}

	// Check for errors
	if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusCreated {
		log.Printf("API error response: %s - %s", resp.Status, string(body))
		return nil, fmt.Errorf("API returned error: %s - %s", resp.Status, string(body))
	}

	// Parse the response
	var result map[string]interface{}
	if err := json.Unmarshal(body, &result); err != nil {
		return nil, fmt.Errorf("error parsing response: %v", err)
	}

	log.Printf("Successfully uploaded attachment %s to job %s", filename, jobID)
	return result, nil
}

// GetAttachmentInfo gets information about a specific attachment
func (s *Session) GetAttachmentInfo(attachmentID string) (map[string]interface{}, error) {
	url := fmt.Sprintf("%s/attachment/%s", BaseURL, attachmentID)

	// Create the request
	req, err := http.NewRequest("GET", url, nil)
	if err != nil {
		return nil, fmt.Errorf("error creating request: %v", err)
	}

	// Set headers
	req.Header.Set("Cookie", s.Cookie)

	// Send the request
	resp, err := s.Client.Do(req)
	if err != nil {
		return nil, fmt.Errorf("error sending request: %v", err)
	}
	defer resp.Body.Close()

	// Read the response
	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, fmt.Errorf("error reading response body: %v", err)
	}

	// Check for errors
	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("API returned error: %s - %s", resp.Status, string(body))
	}

	// Parse the response
	var result map[string]interface{}
	if err := json.Unmarshal(body, &result); err != nil {
		return nil, fmt.Errorf("error parsing response: %v", err)
	}

	return result, nil
}

// DeleteAttachment deletes an attachment
func (s *Session) DeleteAttachment(attachmentID string) error {
	url := fmt.Sprintf("%s/attachment/%s", BaseURL, attachmentID)

	// Create the request
	req, err := http.NewRequest("DELETE", url, nil)
	if err != nil {
		return fmt.Errorf("error creating request: %v", err)
	}

	// Set headers
	req.Header.Set("Cookie", s.Cookie)

	// Send the request
	resp, err := s.Client.Do(req)
	if err != nil {
		return fmt.Errorf("error sending request: %v", err)
	}
	defer resp.Body.Close()

	// Check for errors
	if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusNoContent {
		body, _ := io.ReadAll(resp.Body)
		return fmt.Errorf("API returned error: %s - %s", resp.Status, string(body))
	}

	return nil
}