using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using System.Text.RegularExpressions;
using Newtonsoft.Json;
using StardewModdingAPI.Toolkit.Utilities;
using StardewModdingAPI.Web.Framework.LogParsing.Models;

namespace StardewModdingAPI.Web.ViewModels
{
    /// <summary>The view model for the log parser page.</summary>
    public class LogParserModel
    {
        /*********
        ** Fields
        *********/
        /// <summary>A regex pattern matching characters to remove from a mod name to create the slug ID.</summary>
        private readonly Regex SlugInvalidCharPattern = new("[^a-z0-9]", RegexOptions.Compiled | RegexOptions.IgnoreCase);


        /*********
        ** Accessors
        *********/
        /// <summary>The paste ID.</summary>
        public string? PasteID { get; }

        /// <summary>The viewer's detected OS, if known.</summary>
        public Platform? DetectedPlatform { get; }

        /// <summary>The parsed log info.</summary>
        public ParsedLog? ParsedLog { get; private set; }

        /// <summary>Whether to show the raw unparsed log.</summary>
        public bool ShowRaw { get; private set; }

        /// <summary>A non-blocking warning while uploading the log.</summary>
        public string? UploadWarning { get; set; }

        /// <summary>An error which occurred while uploading the log.</summary>
        public string? UploadError { get; set; }

        /// <summary>An error which occurred while parsing the log file.</summary>
        public string? ParseError => this.ParsedLog?.Error;

        /// <summary>When the uploaded file will no longer be available.</summary>
        public DateTimeOffset? Expiry { get; set; }

        /// <summary>Whether parsed log data is available.</summary>
        [MemberNotNullWhen(true, nameof(LogParserModel.PasteID), nameof(LogParserModel.ParsedLog))]
        public bool HasLog => this.ParsedLog != null;


        /*********
        ** Public methods
        *********/
        /// <summary>Construct an instance.</summary>
        /// <param name="pasteID">The paste ID.</param>
        /// <param name="platform">The viewer's detected OS, if known.</param>
        public LogParserModel(string? pasteID, Platform? platform)
        {
            this.PasteID = pasteID;
            this.DetectedPlatform = platform;
            this.ParsedLog = null;
            this.ShowRaw = false;
        }

        /// <summary>Construct an instance.</summary>
        /// <param name="pasteId">The paste ID.</param>
        /// <param name="detectedPlatform">The viewer's detected OS, if known.</param>
        /// <param name="parsedLog">The parsed log info.</param>
        /// <param name="showRaw">Whether to show the raw unparsed log.</param>
        /// <param name="uploadWarning">A non-blocking warning while uploading the log.</param>
        /// <param name="uploadError">An error which occurred while uploading the log.</param>
        /// <param name="expiry">When the uploaded file will no longer be available.</param>
        [JsonConstructor]
        public LogParserModel(string pasteId, Platform? detectedPlatform, ParsedLog? parsedLog, bool showRaw, string? uploadWarning, string? uploadError, DateTime? expiry)
        {
            this.PasteID = pasteId;
            this.DetectedPlatform = detectedPlatform;
            this.ParsedLog = parsedLog;
            this.ShowRaw = showRaw;
            this.UploadWarning = uploadWarning;
            this.UploadError = uploadError;
            this.Expiry = expiry;
        }

        /// <summary>Set the log parser result.</summary>
        /// <param name="parsedLog">The parsed log info.</param>
        /// <param name="showRaw">Whether to show the raw unparsed log.</param>
        public LogParserModel SetResult(ParsedLog parsedLog, bool showRaw)
        {
            this.ParsedLog = parsedLog;
            this.ShowRaw = showRaw;

            return this;
        }

        /// <summary>Get all content packs in the log grouped by the mod they're for.</summary>
        public IDictionary<string, LogModInfo[]> GetContentPacksByMod()
        {
            // get all mods & content packs
            LogModInfo[]? mods = this.ParsedLog?.Mods;
            if (mods == null || !mods.Any())
                return new Dictionary<string, LogModInfo[]>();

            // group by mod
            return mods
                .Where(mod => mod.IsContentPack)
                .GroupBy(mod => mod.ContentPackFor ?? "")
                .ToDictionary(group => group.Key, group => group.ToArray());
        }

        /// <summary>Get a sanitized mod name that's safe to use in anchors, attributes, and URLs.</summary>
        /// <param name="modName">The mod name.</param>
        public string GetSlug(string modName)
        {
            return this.SlugInvalidCharPattern.Replace(modName, "");
        }
    }
}