add db2autosave feature

pyproject.toml

@@ -33,6 +33,7 @@ dev = [
 
 [project.scripts]
 builder2ibek = "builder2ibek.__main__:cli"
+db2autosave = "builder2ibek.autosave:cli"
 
 [project.urls]
 GitHub = "https://github.com/epics-containers/builder2ibek"

src/builder2ibek/db2autosave.py

@@ -0,0 +1,87 @@
+import re
+from pathlib import Path
+
+import typer
+
+from builder2ibek import __version__
+
+cli = typer.Typer()
+
+
+def version_callback(value: bool):
+    if value:
+        typer.echo(__version__)
+        raise typer.Exit()
+
+
+@cli.callback()
+def main(
+    version: bool | None = typer.Option(
+        None,
+        "--version",
+        callback=version_callback,
+        is_eager=True,
+        help="Print the version of builder2ibek and exit",
+    ),
+):
+    """
+    Convert DLS autosave DB template comments into autosave req files
+    """
+
+
+regex_autosave = [
+    re.compile(rf'# *% *autosave *{n} *(.*)[\s\S]*?record *\(.*, *"?([^"]*)"?\)')
+    for n in range(3)
+]
+
+
+@cli.command()
+def db_files(
+    out_folder: Path = typer.Option(
+        ".", help="Output folder to write autosave request files"
+    ),
+    db_list: list[Path] = typer.Argument(
+        ..., help="List of autosave req files to link "
+    ),
+):
+    """
+    Convert DLS autosave DB template comments into autosave req files
+    """
+    parse_templates(out_folder, db_list)
+
+
+def parse_templates(out_folder: Path, db_list: list[Path]):
+    """
+    DLS has 3 autosave levels
+        0 = save on pass 0
+        1 = save on pass 0 and 1
+        2 = save on pass 1 only
+
+    Areadetector and other support modules use:
+        template_name_positions.req for save on pass 0
+        template_name_settings.req for save on pass 0 and pass 1
+        the autosave docs seem to back the idea that pass 1 only is not used
+
+    So this translation will make
+        0 => template_name_positions.req
+        1 => template_name_settings.req
+    """
+    for db in db_list:
+        text = db.read_text()
+
+        positions = set()
+        settings = set()
+        for n in range(3):
+            match n:
+                case 0:
+                    this_set = positions
+                case 1 | 2:
+                    this_set = settings
+            for match in regex_autosave[n].finditer(text):
+                this_set.add(f"{match.group(2)} {match.group(1)}")
+
+        stem = db.stem
+        req_file = out_folder / f"{stem}_positions.req"
+        req_file.write_text("\n".join(positions))
+        req_file = out_folder / f"{stem}_settings.req"
+        req_file.write_text("\n".join(settings))