package nextcloud

import (
	"context"
	"encoding/json"
	"encoding/xml"
	"fmt"
	"io"
	"strings"
)

type FileInfo struct {
	Path         string `json:"path"`
	Name         string `json:"name"`
	Type         string `json:"type"` // "file" or "directory"
	Size         int64  `json:"size"`
	MimeType     string `json:"mime_type"`
	LastModified string `json:"last_modified"`
	ETag         string `json:"etag"`
}

type ShareInfo struct {
	ID          string `json:"id"`
	Path        string `json:"path"`
	ShareType   int    `json:"share_type"`
	Permissions int    `json:"permissions"`
	URL         string `json:"url"`
	ExpiresAt   string `json:"expires_at,omitempty"`
}

func (c *Client) ListFiles(ctx context.Context, userID, path string) ([]FileInfo, error) {
	davPath := c.WebDAVPath(userID, path)
	body := `<?xml version="1.0" encoding="UTF-8"?>
<d:propfind xmlns:d="DAV:" xmlns:oc="http://owncloud.org/ns" xmlns:nc="http://nextcloud.org/ns">
  <d:prop>
    <d:getlastmodified/>
    <d:getetag/>
    <d:getcontenttype/>
    <d:getcontentlength/>
    <d:resourcetype/>
    <oc:fileid/>
    <oc:size/>
  </d:prop>
</d:propfind>`

	resp, err := c.DoAsUser(ctx, "PROPFIND", davPath, strings.NewReader(body), userID, map[string]string{
		"Depth":        "1",
		"Content-Type": "application/xml",
	})
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()

	if resp.StatusCode != 207 {
		return nil, fmt.Errorf("propfind failed: %d", resp.StatusCode)
	}

	return parsePropfindResponse(resp.Body, davPath)
}

func (c *Client) Upload(ctx context.Context, userID, path string, content io.Reader, contentType string) error {
	davPath := c.WebDAVPath(userID, path)
	headers := map[string]string{}
	if contentType != "" {
		headers["Content-Type"] = contentType
	}

	resp, err := c.DoAsUser(ctx, "PUT", davPath, content, userID, headers)
	if err != nil {
		return err
	}
	defer resp.Body.Close()

	if resp.StatusCode != 201 && resp.StatusCode != 204 {
		return fmt.Errorf("upload failed: %d", resp.StatusCode)
	}
	return nil
}

func (c *Client) Download(ctx context.Context, userID, path string) (io.ReadCloser, string, error) {
	davPath := c.WebDAVPath(userID, path)
	resp, err := c.DoAsUser(ctx, "GET", davPath, nil, userID, nil)
	if err != nil {
		return nil, "", err
	}

	if resp.StatusCode != 200 {
		resp.Body.Close()
		return nil, "", fmt.Errorf("download failed: %d", resp.StatusCode)
	}

	return resp.Body, resp.Header.Get("Content-Type"), nil
}

func (c *Client) CreateFolder(ctx context.Context, userID, path string) error {
	davPath := c.WebDAVPath(userID, path)
	resp, err := c.DoAsUser(ctx, "MKCOL", davPath, nil, userID, nil)
	if err != nil {
		return err
	}
	defer resp.Body.Close()

	if resp.StatusCode != 201 {
		return fmt.Errorf("mkcol failed: %d", resp.StatusCode)
	}
	return nil
}

func (c *Client) Delete(ctx context.Context, userID, path string) error {
	davPath := c.WebDAVPath(userID, path)
	resp, err := c.DoAsUser(ctx, "DELETE", davPath, nil, userID, nil)
	if err != nil {
		return err
	}
	defer resp.Body.Close()

	if resp.StatusCode != 204 {
		return fmt.Errorf("delete failed: %d", resp.StatusCode)
	}
	return nil
}

func (c *Client) Move(ctx context.Context, userID, srcPath, destPath string) error {
	davSrc := c.WebDAVPath(userID, srcPath)
	destURL := c.baseURL + c.WebDAVPath(userID, destPath)
	resp, err := c.DoAsUser(ctx, "MOVE", davSrc, nil, userID, map[string]string{
		"Destination": destURL,
		"Overwrite":   "F",
	})
	if err != nil {
		return err
	}
	defer resp.Body.Close()

	if resp.StatusCode != 201 && resp.StatusCode != 204 {
		return fmt.Errorf("move failed: %d", resp.StatusCode)
	}
	return nil
}

func (c *Client) CreateShare(ctx context.Context, userID, path string, shareType int, permissions int) (*ShareInfo, error) {
	formData := fmt.Sprintf("path=%s&shareType=%d&permissions=%d", path, shareType, permissions)
	resp, err := c.DoAsUser(ctx, "POST", "/ocs/v2.php/apps/files_sharing/api/v1/shares",
		strings.NewReader(formData), userID, map[string]string{
			"Content-Type": "application/x-www-form-urlencoded",
			"Accept":       "application/json",
		})
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()

	var ocsResp struct {
		OCS struct {
			Data struct {
				ID          int    `json:"id"`
				URL         string `json:"url"`
				Permissions int    `json:"permissions"`
				Expiration  string `json:"expiration"`
			} `json:"data"`
		} `json:"ocs"`
	}
	if err := json.NewDecoder(resp.Body).Decode(&ocsResp); err != nil {
		return nil, err
	}

	return &ShareInfo{
		ID:          fmt.Sprintf("%d", ocsResp.OCS.Data.ID),
		Path:        path,
		ShareType:   shareType,
		Permissions: ocsResp.OCS.Data.Permissions,
		URL:         ocsResp.OCS.Data.URL,
		ExpiresAt:   ocsResp.OCS.Data.Expiration,
	}, nil
}

// PROPFIND XML response parsing
type multistatus struct {
	XMLName   xml.Name   `xml:"multistatus"`
	Responses []response `xml:"response"`
}

type response struct {
	Href     string   `xml:"href"`
	Propstat propstat `xml:"propstat"`
}

type propstat struct {
	Prop   prop   `xml:"prop"`
	Status string `xml:"status"`
}

type prop struct {
	LastModified  string       `xml:"getlastmodified"`
	ETag          string       `xml:"getetag"`
	ContentType   string       `xml:"getcontenttype"`
	ContentLength int64        `xml:"getcontentlength"`
	ResourceType  resourceType `xml:"resourcetype"`
	Size          int64        `xml:"size"`
	DisplayName   string       `xml:"displayname"`
	CalendarColor string       `xml:"calendar-color"`
}

type resourceType struct {
	Collection *struct{} `xml:"collection"`
}

func parsePropfindResponse(body io.Reader, basePath string) ([]FileInfo, error) {
	var ms multistatus
	if err := xml.NewDecoder(body).Decode(&ms); err != nil {
		return nil, err
	}

	files := make([]FileInfo, 0, len(ms.Responses))
	for i, r := range ms.Responses {
		if i == 0 {
			continue // skip the folder itself
		}

		name := r.Href
		if idx := strings.LastIndex(strings.TrimSuffix(name, "/"), "/"); idx >= 0 {
			name = name[idx+1:]
		}
		name = strings.TrimSuffix(name, "/")

		fileType := "file"
		if r.Propstat.Prop.ResourceType.Collection != nil {
			fileType = "directory"
		}

		size := r.Propstat.Prop.ContentLength
		if r.Propstat.Prop.Size > 0 {
			size = r.Propstat.Prop.Size
		}

		files = append(files, FileInfo{
			Path:         r.Href,
			Name:         name,
			Type:         fileType,
			Size:         size,
			MimeType:     r.Propstat.Prop.ContentType,
			LastModified: r.Propstat.Prop.LastModified,
			ETag:         strings.Trim(r.Propstat.Prop.ETag, "\""),
		})
	}

	return files, nil
}