1 files changed, 190 insertions, 0 deletions
diff --git a/stddirs.go b/stddirs.go
new file mode 100644
index 0000000..581af87
--- /dev/null
+++ b/stddirs.go
@@ -0,0 +1,190 @@
+package planr
+
+import (
+  "os"
+  "log"
+  "path"
+  "path/filepath"
+)
+
+// Standard Directories:
+//
+// Planr relies on a standard directory structure to resolve paths to source code
+// These directories can be overridden via environmental variables //
+// Directories:
+// - `.`            root directory
+// - `src`          contains source code
+// - `planr`        contains test metadata (also called configuration directory)
+// - `planr/rubric` contains test case configuration
+// - `planr/tests`  contains source code for test cases
+// - `planr/build`  contains all files written during the build process (ephemeral)
+
+// Env overrides
+const (
+  ENV_CONFIG_DIR="PLANR_CONFIG_DIR"
+  ENV_SRC_DIR="PLANR_SRC_DIR"
+  ENV_BUILD_DIR="PLANR_BUILD_DIR"
+)
+
+// Try these search directories
+var CONFIG_SEARCH_DIRS = [] string {
+  "planr",
+  ".planr",
+}
+
+// Path are relative to the "planr" project config directory
+const (
+  DEFAULT_PATH_SRC="../src"
+  DEFAULT_PATH_BUILD="build"
+  DEFAULT_PATH_RUBRIC="rubric"
+  DEFAULT_PATH_TESTS="tests"
+)
+
+type DirConfig struct {
+  src        string
+  config     string
+  build      string
+  
+  // Config falls back to the config found in the parent directory if the env variable hasn't been overridden
+  pdFallback string
+}
+
+func dieDirAbsent(name, path string) {
+  if !directoryExists(path) {
+    log.Fatalf("Could not find %s directory tried %s", name, path)
+  }
+}
+
+func dirFromEnv(name, env string) *string {
+  if dir, isSet := os.LookupEnv(env); isSet {
+    
+    dieDirAbsent(name, dir)
+
+    return &dir
+  }
+
+  return nil
+}
+
+func (c *DirConfig) SetSrc(srcDir string) {
+  dieDirAbsent("src", srcDir)
+  c.src = abs(srcDir)
+}
+
+func (c *DirConfig) SetConfig(configDir string) {
+  dieDirAbsent("planr (config)", configDir)
+  c.config = abs(configDir)
+}
+
+func (c *DirConfig) SetBuild(buildDir string) {
+  dieDirAbsent("build", buildDir)
+  c.build = abs(buildDir)
+}
+
+func (c *DirConfig) SetConfigFromTree(cdir string) {
+  var configDir string
+
+  found := traverseUp(cdir, func (path string) bool {
+
+    for _, dir := range CONFIG_SEARCH_DIRS {
+      configDir = filepath.Join(path, dir)
+
+      if directoryExists(configDir) {
+        return true
+      }
+    }
+
+    return false 
+  });
+
+
+  if found {
+    c.pdFallback = configDir
+  }
+}
+
+func (c DirConfig) Config() string {
+  if c.config != "" {
+    return c.config
+  }
+
+  if dir := dirFromEnv("config", ENV_CONFIG_DIR); dir != nil {
+    c.config = abs(*dir)
+    return c.config
+  }
+
+  if c.pdFallback == "" {
+    log.Fatal("Could not find planr directory");
+  }
+
+  c.config = abs(c.pdFallback);
+  return c.config
+}
+
+func (c DirConfig) Src() string {
+  if c.src != "" {
+    return c.src
+  }
+
+  if dir := dirFromEnv("src", ENV_SRC_DIR); dir != nil {
+    c.src = *dir
+    return c.src
+  }
+
+  // set path relative to config
+  dir := c.Config()
+  return path.Join(dir, DEFAULT_PATH_SRC)
+}
+
+func abs(path string) string {
+  apath, err := filepath.Abs(path)
+
+  if err != nil {
+    log.Fatalf("Could not find path %s", path)
+  }
+
+  return apath
+}
+
+func (c DirConfig) Build() string {
+  if c.build != "" {
+    return c.build
+  }
+
+  if dir := dirFromEnv("build", ENV_BUILD_DIR); dir != nil {
+    c.build = *dir
+    return c.build
+  }
+
+  dir := c.Config()
+  return path.Join(dir, DEFAULT_PATH_BUILD)
+}
+
+func (c DirConfig) CleanBuild() {
+  build := c.Build()
+
+  if err := os.RemoveAll(build); err != nil {
+    log.Fatalf("Cannot build directory %v\n", err)
+  }
+  
+}
+
+func (c DirConfig) MkBuild() {
+  build := c.Build()
+
+  if err := os.Mkdir(build, 0755); err != nil {
+    log.Fatalf("Could not create build directory %v\n", err)
+  }
+}
+
+func (c DirConfig) Rubric() string {
+  rubric := path.Join(c.Config(), DEFAULT_PATH_RUBRIC)
+  dieDirAbsent("rubric", rubric)
+  return rubric
+}
+
+func (c DirConfig) Tests() string {
+  tests := path.Join(c.Config(), DEFAULT_PATH_TESTS)
+  dieDirAbsent("tests", tests)
+  return tests
+}