自动构建

src/Jiaowu.Api/Infrastructure/Configuration/EnvironmentFile.cs

@@ -0,0 +1,165 @@
+using System.Text;
+
+namespace Jiaowu.Api.Infrastructure.Configuration;
+
+public static class EnvironmentFile
+{
+    public const string PathVariableName = "JIAOWU_ENV_FILE";
+
+    public static string? Load(string? path = null)
+    {
+        var configuredPath = path;
+        if (string.IsNullOrWhiteSpace(configuredPath))
+        {
+            configuredPath = Environment.GetEnvironmentVariable(PathVariableName);
+        }
+
+        var isExplicit = !string.IsNullOrWhiteSpace(configuredPath);
+        var resolvedPath = isExplicit
+            ? Path.GetFullPath(configuredPath!, Environment.CurrentDirectory)
+            : Path.Combine(AppContext.BaseDirectory, ".env");
+
+        if (!File.Exists(resolvedPath))
+        {
+            if (isExplicit)
+            {
+                throw new FileNotFoundException(
+                    $"环境变量文件不存在：{resolvedPath}",
+                    resolvedPath);
+            }
+
+            return null;
+        }
+
+        var values = Parse(resolvedPath);
+        foreach (var (key, value) in values)
+        {
+            if (Environment.GetEnvironmentVariable(key) is null)
+            {
+                Environment.SetEnvironmentVariable(key, value);
+            }
+        }
+
+        return resolvedPath;
+    }
+
+    private static Dictionary<string, string> Parse(string path)
+    {
+        var values = new Dictionary<string, string>(StringComparer.Ordinal);
+        var lineNumber = 0;
+        foreach (var sourceLine in File.ReadLines(path, Encoding.UTF8))
+        {
+            lineNumber++;
+            var line = sourceLine.Trim();
+            if (line.Length == 0 || line.StartsWith('#'))
+            {
+                continue;
+            }
+
+            if (line.StartsWith("export ", StringComparison.Ordinal))
+            {
+                line = line[7..].TrimStart();
+            }
+
+            var separatorIndex = line.IndexOf('=');
+            if (separatorIndex <= 0)
+            {
+                throw InvalidLine(path, lineNumber, "缺少 KEY=VALUE 分隔符");
+            }
+
+            var key = line[..separatorIndex].Trim();
+            if (!IsValidKey(key))
+            {
+                throw InvalidLine(path, lineNumber, $"变量名无效：{key}");
+            }
+
+            var rawValue = line[(separatorIndex + 1)..].Trim();
+            values[key] = ParseValue(path, lineNumber, rawValue);
+        }
+
+        return values;
+    }
+
+    private static string ParseValue(string path, int lineNumber, string rawValue)
+    {
+        if (rawValue.Length == 0)
+        {
+            return string.Empty;
+        }
+
+        if (rawValue[0] == '\'')
+        {
+            if (rawValue.Length < 2 || rawValue[^1] != '\'')
+            {
+                throw InvalidLine(path, lineNumber, "单引号值没有正确闭合");
+            }
+
+            return rawValue[1..^1];
+        }
+
+        if (rawValue[0] != '"')
+        {
+            return rawValue;
+        }
+
+        if (rawValue.Length < 2 || rawValue[^1] != '"')
+        {
+            throw InvalidLine(path, lineNumber, "双引号值没有正确闭合");
+        }
+
+        var value = rawValue[1..^1];
+        var result = new StringBuilder(value.Length);
+        for (var index = 0; index < value.Length; index++)
+        {
+            var current = value[index];
+            if (current != '\\' || index == value.Length - 1)
+            {
+                result.Append(current);
+                continue;
+            }
+
+            var escaped = value[++index];
+            switch (escaped)
+            {
+                case 'n':
+                    result.Append('\n');
+                    break;
+                case 'r':
+                    result.Append('\r');
+                    break;
+                case 't':
+                    result.Append('\t');
+                    break;
+                case '\\':
+                    result.Append('\\');
+                    break;
+                case '"':
+                    result.Append('"');
+                    break;
+                default:
+                    result.Append('\\');
+                    result.Append(escaped);
+                    break;
+            }
+        }
+
+        return result.ToString();
+    }
+
+    private static bool IsValidKey(string key)
+    {
+        if (key.Length == 0 || !(char.IsAsciiLetter(key[0]) || key[0] == '_'))
+        {
+            return false;
+        }
+
+        return key.All(character =>
+            char.IsAsciiLetterOrDigit(character) || character == '_');
+    }
+
+    private static FormatException InvalidLine(
+        string path,
+        int lineNumber,
+        string reason) =>
+        new($"{path} 第 {lineNumber} 行无效：{reason}。");
+}