1 files changed, 103 insertions, 0 deletions
diff --git a/src/TrainerMod/Framework/Commands/TrainerCommand.cs b/src/TrainerMod/Framework/Commands/TrainerCommand.cs
new file mode 100644
index 00000000..abe9ee41
--- /dev/null
+++ b/src/TrainerMod/Framework/Commands/TrainerCommand.cs
@@ -0,0 +1,103 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using StardewModdingAPI;
+
+namespace TrainerMod.Framework.Commands
+{
+    /// <summary>The base implementation for a trainer command.</summary>
+    internal abstract class TrainerCommand : ITrainerCommand
+    {
+        /*********
+        ** Accessors
+        *********/
+        /// <summary>The command name the user must type.</summary>
+        public string Name { get; }
+
+        /// <summary>The command description.</summary>
+        public string Description { get; }
+
+        /// <summary>Whether the command needs to perform logic when the game updates.</summary>
+        public virtual bool NeedsUpdate { get; } = false;
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Handle the command.</summary>
+        /// <param name="monitor">Writes messages to the console and log file.</param>
+        /// <param name="command">The command name.</param>
+        /// <param name="args">The command arguments.</param>
+        public abstract void Handle(IMonitor monitor, string command, ArgumentParser args);
+
+        /// <summary>Perform any logic needed on update tick.</summary>
+        /// <param name="monitor">Writes messages to the console and log file.</param>
+        public virtual void Update(IMonitor monitor) { }
+
+
+        /*********
+        ** Protected methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="name">The command name the user must type.</param>
+        /// <param name="description">The command description.</param>
+        protected TrainerCommand(string name, string description)
+        {
+            this.Name = name;
+            this.Description = description;
+        }
+
+        /// <summary>Log an error indicating incorrect usage.</summary>
+        /// <param name="monitor">Writes messages to the console and log file.</param>
+        /// <param name="error">A sentence explaining the problem.</param>
+        protected void LogUsageError(IMonitor monitor, string error)
+        {
+            monitor.Log($"{error} Type 'help {this.Name}' for usage.", LogLevel.Error);
+        }
+
+        /// <summary>Log an error indicating a value must be an integer.</summary>
+        /// <param name="monitor">Writes messages to the console and log file.</param>
+        protected void LogArgumentNotInt(IMonitor monitor)
+        {
+            this.LogUsageError(monitor, "The value must be a whole number.");
+        }
+
+        /// <summary>Get an ASCII table to show tabular data in the console.</summary>
+        /// <typeparam name="T">The data type.</typeparam>
+        /// <param name="data">The data to display.</param>
+        /// <param name="header">The table header.</param>
+        /// <param name="getRow">Returns a set of fields for a data value.</param>
+        protected string GetTableString<T>(IEnumerable<T> data, string[] header, Func<T, string[]> getRow)
+        {
+            // get table data
+            int[] widths = header.Select(p => p.Length).ToArray();
+            string[][] rows = data
+                .Select(item =>
+                {
+                    string[] fields = getRow(item);
+                    if (fields.Length != widths.Length)
+                        throw new InvalidOperationException($"Expected {widths.Length} columns, but found {fields.Length}: {string.Join(", ", fields)}");
+
+                    for (int i = 0; i < fields.Length; i++)
+                        widths[i] = Math.Max(widths[i], fields[i].Length);
+
+                    return fields;
+                })
+                .ToArray();
+
+            // render fields
+            List<string[]> lines = new List<string[]>(rows.Length + 2)
+            {
+                header,
+                header.Select((value, i) => "".PadRight(widths[i], '-')).ToArray()
+            };
+            lines.AddRange(rows);
+
+            return string.Join(
+                Environment.NewLine,
+                lines.Select(line => string.Join(" | ", line.Select((field, i) => field.PadRight(widths[i], ' ')).ToArray())
+                )
+            );
+        }
+    }
+}