1 files changed, 245 insertions, 0 deletions
diff --git a/src/SMAPI.Web/Framework/LogParsing/LogParser.cs b/src/SMAPI.Web/Framework/LogParsing/LogParser.cs
new file mode 100644
index 00000000..23a1baa4
--- /dev/null
+++ b/src/SMAPI.Web/Framework/LogParsing/LogParser.cs
@@ -0,0 +1,245 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text.RegularExpressions;
+using StardewModdingAPI.Web.Framework.LogParsing.Models;
+
+namespace StardewModdingAPI.Web.Framework.LogParsing
+{
+    /// <summary>Parses SMAPI log files.</summary>
+    public class LogParser
+    {
+        /*********
+        ** Properties
+        *********/
+        /// <summary>A regex pattern matching the start of a SMAPI message.</summary>
+        private readonly Regex MessageHeaderPattern = new Regex(@"^\[(?<time>\d\d:\d\d:\d\d) (?<level>[a-z]+) +(?<modName>[^\]]+)\] ", RegexOptions.Compiled | RegexOptions.IgnoreCase);
+
+        /// <summary>A regex pattern matching SMAPI's initial platform info message.</summary>
+        private readonly Regex InfoLinePattern = new Regex(@"^SMAPI (?<apiVersion>.+) with Stardew Valley (?<gameVersion>.+) on (?<os>.+)", RegexOptions.Compiled | RegexOptions.IgnoreCase);
+
+        /// <summary>A regex pattern matching SMAPI's mod folder path line.</summary>
+        private readonly Regex ModPathPattern = new Regex(@"^Mods go here: (?<path>.+)", RegexOptions.Compiled | RegexOptions.IgnoreCase);
+
+        /// <summary>A regex pattern matching SMAPI's log timestamp line.</summary>
+        private readonly Regex LogStartedAtPattern = new Regex(@"^Log started at (?<timestamp>.+) UTC", RegexOptions.Compiled | RegexOptions.IgnoreCase);
+
+        /// <summary>A regex pattern matching the start of SMAPI's mod list.</summary>
+        private readonly Regex ModListStartPattern = new Regex(@"^Loaded \d+ mods:$", RegexOptions.Compiled | RegexOptions.IgnoreCase);
+
+        /// <summary>A regex pattern matching an entry in SMAPI's mod list.</summary>
+        private readonly Regex ModListEntryPattern = new Regex(@"^   (?<name>.+) (?<version>.+) by (?<author>.+) \| (?<description>.+)$", RegexOptions.Compiled | RegexOptions.IgnoreCase);
+
+        /// <summary>A regex pattern matching the start of SMAPI's content pack list.</summary>
+        private readonly Regex ContentPackListStartPattern = new Regex(@"^Loaded \d+ content packs:$", RegexOptions.Compiled | RegexOptions.IgnoreCase);
+
+        /// <summary>A regex pattern matching an entry in SMAPI's content pack list.</summary>
+        private readonly Regex ContentPackListEntryPattern = new Regex(@"^   (?<name>.+) (?<version>.+) by (?<author>.+) \| for (?<for>.+?) \| (?<description>.+)$", RegexOptions.Compiled | RegexOptions.IgnoreCase);
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Parse SMAPI log text.</summary>
+        /// <param name="logText">The SMAPI log text.</param>
+        public ParsedLog Parse(string logText)
+        {
+            try
+            {
+                // skip if empty
+                if (string.IsNullOrWhiteSpace(logText))
+                {
+                    return new ParsedLog
+                    {
+                        IsValid = false,
+                        Error = "The log is empty."
+                    };
+                }
+
+                // init log
+                ParsedLog log = new ParsedLog
+                {
+                    IsValid = true,
+                    Messages = this.CollapseRepeats(this.GetMessages(logText)).ToArray(),
+                };
+
+                // parse log messages
+                LogModInfo smapiMod = new LogModInfo { Name = "SMAPI", Author = "Pathoschild", Description = "" };
+                IDictionary<string, LogModInfo> mods = new Dictionary<string, LogModInfo>();
+                bool inModList = false;
+                bool inContentPackList = false;
+                foreach (LogMessage message in log.Messages)
+                {
+                    // collect stats
+                    if (message.Level == LogLevel.Error)
+                    {
+                        if (message.Mod == "SMAPI")
+                            smapiMod.Errors++;
+                        else if (mods.ContainsKey(message.Mod))
+                            mods[message.Mod].Errors++;
+                    }
+
+                    // collect SMAPI metadata
+                    if (message.Mod == "SMAPI")
+                    {
+                        // update flags
+                        if (inModList && !this.ModListEntryPattern.IsMatch(message.Text))
+                            inModList = false;
+                        if (inContentPackList && !this.ContentPackListEntryPattern.IsMatch(message.Text))
+                            inContentPackList = false;
+
+                        // mod list
+                        if (!inModList && message.Level == LogLevel.Info && this.ModListStartPattern.IsMatch(message.Text))
+                            inModList = true;
+                        else if (inModList)
+                        {
+                            Match match = this.ModListEntryPattern.Match(message.Text);
+                            string name = match.Groups["name"].Value;
+                            string version = match.Groups["version"].Value;
+                            string author = match.Groups["author"].Value;
+                            string description = match.Groups["description"].Value;
+                            mods[name] = new LogModInfo { Name = name, Author = author, Version = version, Description = description };
+                        }
+
+                        // content pack list
+                        else if (!inContentPackList && message.Level == LogLevel.Info && this.ContentPackListStartPattern.IsMatch(message.Text))
+                            inContentPackList = true;
+                        else if (inContentPackList)
+                        {
+                            Match match = this.ContentPackListEntryPattern.Match(message.Text);
+                            string name = match.Groups["name"].Value;
+                            string version = match.Groups["version"].Value;
+                            string author = match.Groups["author"].Value;
+                            string description = match.Groups["description"].Value;
+                            string forMod = match.Groups["for"].Value;
+                            mods[name] = new LogModInfo { Name = name, Author = author, Version = version, Description = description, ContentPackFor = forMod };
+                        }
+
+                        // platform info line
+                        else if (message.Level == LogLevel.Info && this.InfoLinePattern.IsMatch(message.Text))
+                        {
+                            Match match = this.InfoLinePattern.Match(message.Text);
+                            log.ApiVersion = match.Groups["apiVersion"].Value;
+                            log.GameVersion = match.Groups["gameVersion"].Value;
+                            log.OperatingSystem = match.Groups["os"].Value;
+                            smapiMod.Version = log.ApiVersion;
+                        }
+
+                        // mod path line
+                        else if (message.Level == LogLevel.Debug && this.ModPathPattern.IsMatch(message.Text))
+                        {
+                            Match match = this.ModPathPattern.Match(message.Text);
+                            log.ModPath = match.Groups["path"].Value;
+                        }
+
+                        // log UTC timestamp line
+                        else if (message.Level == LogLevel.Trace && this.LogStartedAtPattern.IsMatch(message.Text))
+                        {
+                            Match match = this.LogStartedAtPattern.Match(message.Text);
+                            log.Timestamp = DateTime.Parse(match.Groups["timestamp"].Value + "Z");
+                        }
+                    }
+                }
+
+                // finalise log
+                log.Mods = new[] { smapiMod }.Concat(mods.Values.OrderBy(p => p.Name)).ToArray();
+                return log;
+            }
+            catch (LogParseException ex)
+            {
+                return new ParsedLog
+                {
+                    IsValid = false,
+                    Error = ex.Message,
+                    RawTextIfError = logText
+                };
+            }
+            catch (Exception ex)
+            {
+                return new ParsedLog
+                {
+                    IsValid = false,
+                    Error = $"Parsing the log file failed. Technical details:\n{ex}",
+                    RawTextIfError = logText
+                };
+            }
+        }
+
+
+        /*********
+        ** Private methods
+        *********/
+        /// <summary>Collapse consecutive repeats into the previous message.</summary>
+        /// <param name="messages">The messages to filter.</param>
+        private IEnumerable<LogMessage> CollapseRepeats(IEnumerable<LogMessage> messages)
+        {
+            LogMessage next = null;
+            foreach (LogMessage message in messages)
+            {
+                // new message
+                if (next == null)
+                {
+                    next = message;
+                    continue;
+                }
+
+                // repeat
+                if (next.Level == message.Level && next.Mod == message.Mod && next.Text == message.Text)
+                {
+                    next.Repeated++;
+                    continue;
+                }
+
+                // non-repeat message
+                yield return next;
+                next = message;
+            }
+            yield return next;
+        }
+
+        /// <summary>Split a SMAPI log into individual log messages.</summary>
+        /// <param name="logText">The SMAPI log text.</param>
+        /// <exception cref="LogParseException">The log text can't be parsed successfully.</exception>
+        private IEnumerable<LogMessage> GetMessages(string logText)
+        {
+            LogMessage message = new LogMessage();
+            using (StringReader reader = new StringReader(logText))
+            {
+                while (true)
+                {
+                    // read data
+                    string line = reader.ReadLine();
+                    if (line == null)
+                        break;
+                    Match header = this.MessageHeaderPattern.Match(line);
+
+                    // validate
+                    if (message.Text == null && !header.Success)
+                        throw new LogParseException("Found a log message with no SMAPI metadata. Is this a SMAPI log file?");
+
+                    // start or continue message
+                    if (header.Success)
+                    {
+                        if (message.Text != null)
+                            yield return message;
+
+                        message = new LogMessage
+                        {
+                            Time = header.Groups["time"].Value,
+                            Level = Enum.Parse<LogLevel>(header.Groups["level"].Value, ignoreCase: true),
+                            Mod = header.Groups["modName"].Value,
+                            Text = line.Substring(header.Length)
+                        };
+                    }
+                    else
+                        message.Text += "\n" + line;
+                }
+
+                // end last message
+                if (message.Text != null)
+                    yield return message;
+            }
+        }
+    }
+}