PageMetaData.cs

using System;
using System.Collections.Generic;
using System.Text;
using Waher.Content.Html.Elements;
using Waher.Content.Html.OpenGraph;
 
namespace Waher.Content.Html
{
    public class PageMetaData
    {
        private ImageInformation[] images = null;
        private AudioInformation[] audio = null;
        private VideoInformation[] video = null;
        private string[] localeAlternate = null;
        private string title = null;
        private string type = null;
        private string url = null;
        private string description = null;
        private string determiner = null;
        private string locale = null;
        private string siteName = null;
 
        public PageMetaData()
        {
        }
 
        public PageMetaData(HtmlDocument Doc)
        {
            List<ImageInformation> Images = null;
            List<AudioInformation> Audio = null;
            List<VideoInformation> Video = null;
            List<string> LocaleAlternate = null;
            ImageInformation LastImage = null;
            AudioInformation LastAudio = null;
            VideoInformation LastVideo = null;
            string Name;
            string Value;
 
            if (!(Doc.Meta is null))
            {
                foreach (Meta Meta in Doc.Meta)
                {
                    if (!Meta.HasAttributes)
                        continue;
 
                    Name = Value = null;
 
                    if (Meta.HasAttributes)
                    {
                        foreach (HtmlAttribute Attr in Meta.Attributes)
                        {
                            switch (Attr.Name)
                            {
                                case "property":
                                case "name":
                                    Name = Attr.Value;
                                    break;
 
                                case "content":
                                    Value = Attr.Value;
                                    break;
                            }
                        }
                    }
 
                    if (string.IsNullOrEmpty(Name) || string.IsNullOrEmpty(Value))
                        continue;
 
                    switch (Name)
                    {
                        case "og:title":
                            this.title = Value;
                            break;
 
                        case "twitter:title":
                            if (string.IsNullOrEmpty(this.title))
                                this.title = Value;
                            break;
 
                        case "og:type":
                            this.type = Value;
                            break;
 
                        case "twitter:card":
                            if (string.IsNullOrEmpty(this.type))
                                this.type = Value;
                            break;
 
                        case "og:url":
                            this.url = Value;
                            break;
 
                        case "og:image":
                        case "og:image:url":
                        case "twitter:image":
                            if (!(Images is null))
                            {
                                LastImage = null;
 
                                foreach (ImageInformation Image in Images)
                                {
                                    if (Image.Url == Value)
                                    {
                                        LastImage = Image;
                                        break;
                                    }
                                }
 
                                if (!(LastImage is null))
                                    break;
                            }
 
                            LastImage = new ImageInformation()
                            {
                                Url = Value
                            };
 
                            if (Images is null)
                                Images = new List<ImageInformation>();
 
                            Images.Add(LastImage);
                            break;
 
                        case "og:image:secure_url":
                            if (!(LastImage is null))
                                LastImage.SecureUrl = Value;
                            break;
 
                        case "og:image:type":
                            if (!(LastImage is null))
                                LastImage.ContentType = Value;
                            break;
 
                        case "og:image:width":
                            if (!(LastImage is null) && int.TryParse(Value, out int i))
                                LastImage.Width = i;
                            break;
 
                        case "og:image:height":
                            if (!(LastImage is null) && int.TryParse(Value, out i))
                                LastImage.Height = i;
                            break;
 
                        case "og:image:alt":
                        case "twitter:image:alt":
                            if (!(LastImage is null))
                                LastImage.Description = Value;
                            break;
 
                        case "og:audio":
                            LastAudio = new AudioInformation()
                            {
                                Url = Value
                            };
 
                            if (Audio is null)
                                Audio = new List<AudioInformation>();
 
                            Audio.Add(LastAudio);
                            break;
 
                        case "og:audio:secure_url":
                            if (!(LastAudio is null))
                                LastAudio.SecureUrl = Value;
                            break;
 
                        case "og:audio:type":
                            if (!(LastAudio is null))
                                LastAudio.ContentType = Value;
                            break;
 
                        case "og:description":
                            this.description = Value;
                            break;
 
                        case "twitter:description":
                        case "description":
                            if (string.IsNullOrEmpty(this.description))
                                this.description = Value;
                            break;
 
                        case "og:determiner":
                            this.determiner = Value;
                            break;
 
                        case "og:locale":
                            this.locale = Value;
                            break;
 
                        case "og:locale:alternate":
                            if (LocaleAlternate is null)
                                LocaleAlternate = new List<string>();
 
                            LocaleAlternate.Add(Value);
                            break;
 
                        case "og:site_name":
                            this.siteName = Value;
                            break;
 
                        case "og:video":
                            LastVideo = new VideoInformation()
                            {
                                Url = Value
                            };
 
                            if (Video is null)
                                Video = new List<VideoInformation>();
 
                            Video.Add(LastVideo);
                            break;
 
                        case "og:video:secure_url":
                            if (!(LastVideo is null))
                                LastVideo.SecureUrl = Value;
                            break;
 
                        case "og:video:type":
                            if (!(LastVideo is null))
                                LastVideo.ContentType = Value;
                            break;
 
                        case "og:video:width":
                            if (!(LastVideo is null) && int.TryParse(Value, out i))
                                LastVideo.Width = i;
                            break;
 
                        case "og:video:height":
                            if (!(LastVideo is null) && int.TryParse(Value, out i))
                                LastVideo.Height = i;
                            break;
                    }
                }
            }
 
            if (string.IsNullOrEmpty(this.title) && !(Doc.Title is null))
                this.title = Doc.Title.InnerText.Trim();
 
            this.images = Images?.ToArray();
            this.audio = Audio?.ToArray();
            this.video = Video?.ToArray();
            this.localeAlternate = LocaleAlternate?.ToArray();
        }
 
        public ImageInformation[] Images
        {
            get => this.images;
            set => this.images = value;
        }
 
        public AudioInformation[] Audio
        {
            get => this.audio;
            set => this.audio = value;
        }
 
        public VideoInformation[] Video
        {
            get => this.video;
            set => this.video = value;
        }
 
        public string[] LocaleAlternate
        {
            get => this.localeAlternate;
            set => this.localeAlternate = value;
        }
 
        public string Title
        {
            get => this.title;
            set => this.title = value;
        }
 
        public string Type
        {
            get => this.type;
            set => this.type = value;
        }
 
        public string Url
        {
            get => this.url;
            set => this.url = value;
        }
 
        public string Description
        {
            get => this.description;
            set => this.description = value;
        }
 
        public string Determiner
        {
            get => this.determiner;
            set => this.determiner = value;
        }
 
        public string Locale
        {
            get => this.locale;
            set => this.locale = value;
        }
 
        public string SiteName
        {
            get => this.siteName;
            set => this.siteName = value;
        }
 
        public override bool Equals(object obj)
        {
            PageMetaData Meta = obj as PageMetaData;
            int i, c;
 
            if ((this is null) ^ (Meta is null))
                return false;
 
            if (this is null)
                return true;
 
            if (this.title != Meta.title ||
                this.type != Meta.type ||
                this.url != Meta.url ||
                this.description != Meta.description ||
                this.determiner != Meta.determiner ||
                this.locale != Meta.locale ||
                this.siteName != Meta.siteName)
            {
                return false;
            }
 
            if ((this.localeAlternate is null) ^ (Meta.localeAlternate is null))
                return false;
 
            if (!(this.localeAlternate is null))
            {
                if ((c = this.localeAlternate.Length) != Meta.localeAlternate.Length)
                    return false;
 
                for (i = 0; i < c; i++)
                {
                    if (this.localeAlternate[i] != Meta.localeAlternate[i])
                        return false;
                }
            }
 
            if ((this.images is null) ^ (Meta.images is null))
                return false;
 
            if (!(this.images is null))
            {
                if ((c = this.images.Length) != Meta.images.Length)
                    return false;
 
                for (i = 0; i < c; i++)
                {
                    if (!this.images[i].Equals(Meta.images[i]))
                        return false;
                }
            }
 
            if ((this.audio is null) ^ (Meta.audio is null))
                return false;
 
            if (!(this.audio is null))
            {
                if ((c = this.audio.Length) != Meta.audio.Length)
                    return false;
 
                for (i = 0; i < c; i++)
                {
                    if (!this.audio[i].Equals(Meta.audio[i]))
                        return false;
                }
            }
 
            if ((this.video is null) ^ (Meta.video is null))
                return false;
 
            if (!(this.video is null))
            {
                if ((c = this.video.Length) != Meta.video.Length)
                    return false;
 
                for (i = 0; i < c; i++)
                {
                    if (!this.video[i].Equals(Meta.video[i]))
                        return false;
                }
            }
 
            return true;
        }
 
        public override int GetHashCode()
        {
            int Result = 0;
 
            if (!(this.title is null))
                Result = this.title.GetHashCode();
 
            if (!(this.type is null))
                Result ^= Result << 5 ^ this.type.GetHashCode();
 
            if (!(this.url is null))
                Result ^= Result << 5 ^ this.url.GetHashCode();
 
            if (!(this.description is null))
                Result ^= Result << 5 ^ this.description.GetHashCode();
 
            if (!(this.determiner is null))
                Result ^= Result << 5 ^ this.determiner.GetHashCode();
 
            if (!(this.locale is null))
                Result ^= Result << 5 ^ this.locale.GetHashCode();
 
            if (!(this.siteName is null))
                Result ^= Result << 5 ^ this.siteName.GetHashCode();
 
            if (!(this.localeAlternate is null))
            {
                foreach (string s in this.localeAlternate)
                    Result ^= Result << 5 ^ s.GetHashCode();
            }
 
            if (!(this.images is null))
            {
                foreach (ImageInformation Obj in this.images)
                    Result ^= Result << 5 ^ Obj.GetHashCode();
            }
 
            if (!(this.audio is null))
            {
                foreach (AudioInformation Obj in this.audio)
                    Result ^= Result << 5 ^ Obj.GetHashCode();
            }
 
            if (!(this.video is null))
            {
                foreach (VideoInformation Obj in this.video)
                    Result ^= Result << 5 ^ Obj.GetHashCode();
            }
 
            return Result;
        }
 
    }
}