/*
   Copyright (c) 2024 mabiao0525 (马飚)

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU Affero General Public License as published
   by the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU Affero General Public License for more details.

   You should have received a copy of the GNU Affero General Public License
   along with this program.  If not, see <https://www.gnu.org/licenses/>.
*/

package docx

import (
	"encoding/xml"
	"io"
	"strconv"
	"strings"
)

// SectPr show the properties of the document, like paper size
type SectPr struct {
	XMLName xml.Name `xml:"w:sectPr,omitempty"` // properties of the document, including paper size
	PgSz    *PgSz    `xml:"w:pgSz,omitempty"`
	PgMar   *PgMar   `xml:"w:pgMar,omitempty"`
	Cols    *Cols    `xml:"w:cols,omitempty"`
	DocGrid *DocGrid `xml:"w:docGrid,omitempty"`
}

// PgSz show the paper size
type PgSz struct {
	W int `xml:"w:w,attr"` // width of paper
	H int `xml:"w:h,attr"` // high of paper
}

// PgMar show the page margin
type PgMar struct {
	Top    int `xml:"w:top,attr"`
	Left   int `xml:"w:left,attr"`
	Bottom int `xml:"w:bottom,attr"`
	Right  int `xml:"w:right,attr"`
	Header int `xml:"w:header,attr"`
	Footer int `xml:"w:footer,attr"`
	Gutter int `xml:"w:gutter,attr"`
}

// Cols show the number of columns
type Cols struct {
	Space int `xml:"w:space,attr"`
}

// DocGrid show the document grid
type DocGrid struct {
	Type      string `xml:"w:type,attr"`
	LinePitch int    `xml:"w:linePitch,attr"`
}

// UnmarshalXML ...
func (sect *SectPr) UnmarshalXML(d *xml.Decoder, _ xml.StartElement) error {
	for {
		t, err := d.Token()
		if err == io.EOF {
			break
		}
		if err != nil {
			return err
		}
		if tt, ok := t.(xml.StartElement); ok {
			switch tt.Name.Local {
			case "pgSz":
				var value PgSz
				err = d.DecodeElement(&value, &tt)
				if err != nil && !strings.HasPrefix(err.Error(), "expected") {
					return err
				}
				sect.PgSz = &value
			case "pgMar":
				var value PgMar
				err = d.DecodeElement(&value, &tt)
				if err != nil && !strings.HasPrefix(err.Error(), "expected") {
					return err
				}
				sect.PgMar = &value
			case "cols":
				var value Cols
				err = d.DecodeElement(&value, &tt)
				if err != nil && !strings.HasPrefix(err.Error(), "expected") {
					return err
				}
				sect.Cols = &value
			case "docGrid":
				var value DocGrid
				err = d.DecodeElement(&value, &tt)
				if err != nil && !strings.HasPrefix(err.Error(), "expected") {
					return err
				}
				sect.DocGrid = &value
			default:
				err = d.Skip() // skip unsupported tags
				if err != nil {
					return err
				}
			}
		}
	}
	return nil
}

// UnmarshalXML ...
func (pgsz *PgSz) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
	var err error

	for _, attr := range start.Attr {
		switch attr.Name.Local {
		case "w":
			pgsz.W, err = strconv.Atoi(attr.Value)
			if err != nil {
				return err
			}
		case "h":
			pgsz.H, err = strconv.Atoi(attr.Value)
			if err != nil {
				return err
			}
		default:
			// ignore other attributes now
		}
	}
	// Consume the end element
	_, err = d.Token()
	return err
}

// UnmarshalXML ...
func (pgmar *PgMar) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
	var err error

	for _, attr := range start.Attr {
		switch attr.Name.Local {
		case "top":
			pgmar.Top, err = strconv.Atoi(attr.Value)
			if err != nil {
				return err
			}
		case "left":
			pgmar.Left, err = strconv.Atoi(attr.Value)
			if err != nil {
				return err
			}
		case "bottom":
			pgmar.Bottom, err = strconv.Atoi(attr.Value)
			if err != nil {
				return err
			}
		case "right":
			pgmar.Right, err = strconv.Atoi(attr.Value)
			if err != nil {
				return err
			}
		case "header":
			pgmar.Header, err = strconv.Atoi(attr.Value)
			if err != nil {
				return err
			}
		case "footer":
			pgmar.Footer, err = strconv.Atoi(attr.Value)
			if err != nil {
				return err
			}
		case "gutter":
			pgmar.Gutter, err = strconv.Atoi(attr.Value)
			if err != nil {
				return err
			}
		default:
			// ignore other attributes now
		}
	}
	// Consume the end element
	_, err = d.Token()
	return err
}

// UnmarshalXML ...
func (cols *Cols) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
	var err error

	for _, attr := range start.Attr {
		switch attr.Name.Local {
		case "space":
			cols.Space, err = strconv.Atoi(attr.Value)
			if err != nil {
				return err
			}
		default:
			// ignore other attributes now
		}
	}
	// Consume the end element
	_, err = d.Token()
	return err
}

// UnmarshalXML ...
func (dg *DocGrid) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
	var err error

	for _, attr := range start.Attr {
		switch attr.Name.Local {
		case "linePitch":
			dg.LinePitch, err = strconv.Atoi(attr.Value)
			if err != nil {
				return err
			}
		case "type":
			dg.Type = attr.Value
		default:
			// ignore other attributes now
		}
	}
	// Consume the end element
	_, err = d.Token()
	return err
}