deploy: df549555ea

viv.py

@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-"""Viv isn't venv!
+"""viv isn't venv!
 
   viv -h
     OR
@@ -31,7 +31,6 @@ from argparse import (
     _SubParsersAction,
 )
 from argparse import ArgumentParser as StdArgParser
-from dataclasses import dataclass
 from datetime import datetime
 from itertools import zip_longest
 from pathlib import Path
@@ -52,7 +51,7 @@ from typing import (
 from urllib.error import HTTPError
 from urllib.request import urlopen
 
-__version__ = "23.5a4"
+__version__ = "23.5a4-13-ga6bd81d-dev"
 
 
 class Config:
@@ -147,37 +146,35 @@ class Spinner:
             sys.stderr.write("\r")
 
 
-BOX: Dict[str, str] = {
-    "v": "│",
-    "h": "─",
-    "tl": "╭",
-    "tr": "╮",
-    "bl": "╰",
-    "br": "╯",
-    "sep": "┆",
-}
-
-
-@dataclass
 class Ansi:
     """control ouptut of ansi(VT100) control codes"""
 
-    bold: str = "\033[1m"
+    BOX: Dict[str, str] = {
-    dim: str = "\033[2m"
+        "v": "│",
-    underline: str = "\033[4m"
+        "h": "─",
-    red: str = "\033[1;31m"
+        "tl": "╭",
-    green: str = "\033[1;32m"
+        "tr": "╮",
-    yellow: str = "\033[1;33m"
+        "bl": "╰",
-    magenta: str = "\033[1;35m"
+        "br": "╯",
-    cyan: str = "\033[1;36m"
+        "sep": "┆",
-    end: str = "\033[0m"
+    }
 
-    # for argparse help
+    def __init__(self) -> None:
-    header: str = cyan
+        self.bold: str = "\033[1m"
-    option: str = yellow
+        self.dim: str = "\033[2m"
-    metavar: str = "\033[33m"  # normal yellow
+        self.underline: str = "\033[4m"
+        self.red: str = "\033[1;31m"
+        self.green: str = "\033[1;32m"
+        self.yellow: str = "\033[1;33m"
+        self.magenta: str = "\033[1;35m"
+        self.cyan: str = "\033[1;36m"
+        self.end: str = "\033[0m"
+
+        # for argparse help
+        self.header: str = self.cyan
+        self.option: str = self.yellow
+        self.metavar: str = "\033[33m"  # normal yellow
 
-    def __post_init__(self) -> None:
         if os.getenv("NO_COLOR") or not sys.stderr.isatty():
             for attr in self.__dict__:
                 setattr(self, attr, "")
@@ -216,7 +213,7 @@ class Ansi:
         return " ".join(
             (
                 self.style(f, "magenta") + self.style(rest, "cyan")
-                for f, rest in (("V", "iv"), ("i", "sn't"), ("v", "env!"))
+                for f, rest in (("v", "iv"), ("i", "sn't"), ("v", "env!"))
             )
         )
 
@@ -243,7 +240,11 @@ class Ansi:
         return list(max(map(len, lst)) for lst in map(list, zip(*rows)))  # type: ignore
 
     def _make_row(self, row: Generator[Any, None, None]) -> str:
-        return f"  {BOX['v']} " + f" {BOX['sep']} ".join(row) + f" {BOX['v']}"
+        return (
+            f"  {self.BOX['v']} "
+            + f" {self.BOX['sep']} ".join(row)
+            + f" {self.BOX['v']}"
+        )
 
     def _sanitize_row(
         self, sizes: List[int], row: Tuple[str, Sequence[str]]
@@ -260,7 +261,7 @@ class Ansi:
             return (row,)
 
     def viv_preamble(self, style: str = "magenta", sep: str = "::") -> str:
-        return f"{self.cyan}Viv{self.end}{self.__dict__[style]}{sep}{self.end}"
+        return f"{self.cyan}viv{self.end}{self.__dict__[style]}{sep}{self.end}"
 
     def table(
         self, rows: Tuple[Tuple[str, Sequence[str]], ...], header_style: str = "cyan"
@@ -302,14 +303,186 @@ class Ansi:
             )
         )
 
-        sys.stderr.write(f"  {BOX['tl']}{BOX['h']*(sum(sizes)+5)}{BOX['tr']}\n")
+        sys.stderr.write(
+            "".join(
+                (
+                    "  ",
+                    self.BOX["tl"],
+                    self.BOX["h"] * (sum(sizes) + 5),
+                    self.BOX["tr"],
+                    "\n",
+                )
+            )
+        )
         sys.stderr.write("\n".join(table_rows) + "\n")
-        sys.stderr.write(f"  {BOX['bl']}{BOX['h']*(sum(sizes)+5)}{BOX['br']}\n")
+        sys.stderr.write(
+            "".join(
+                (
+                    "  ",
+                    self.BOX["bl"],
+                    self.BOX["h"] * (sum(sizes) + 5),
+                    self.BOX["br"],
+                    "\n",
+                )
+            )
+        )
 
 
 a = Ansi()
 
 
+class Template:
+    description = f"""
+
+{a.tagline()}
+to create/activate a vivenv:
+- from command line: `{a.style("viv -h","bold")}`
+- within python script: {a.style('__import__("viv").use("typer", "rich-click")','bold')}
+"""
+    _standalone_func = r"""def _viv_use(*pkgs, track_exe=False, name=""):
+    T,F,N=True,False,None;i,s,m,spec=__import__,str,map,[*pkgs]
+    e,w=lambda x: T if x else F,lambda p,t: p.write_text(t)
+    if not {*m(type,pkgs)}=={s}: raise ValueError(f"spec: {pkgs} is invalid")
+    ge,sys,P,ew=i("os").getenv,i("sys"),i("pathlib").Path,i("sys").stderr.write
+    (cache:=(P(ge("XDG_CACHE_HOME",P.home()/".cache"))/"viv"/"venvs")).mkdir(parents=T,exist_ok=T)
+    ((sha256:=i("hashlib").sha256()).update((s(spec)+
+    (((exe:=("N/A",s(P(i("sys").executable).resolve()))[e(track_exe)])))).encode()))
+    if {env:=cache/(((_id:=sha256.hexdigest()),name)[e(name)])}-{*cache.glob("*/")} or ge("VIV_FORCE"):
+        v=e(ge("VIV_VERBOSE"));ew(f"generating new vivenv -> {env.name}\n")
+        i("venv").EnvBuilder(with_pip=T,clear=T).create(env)
+        w(env/"pip.conf","[global]\ndisable-pip-version-check=true")
+        if (rc:=(p:=i("subprocess").run([env/"bin"/"pip","install","--force-reinstall",*spec],text=T,
+            stdout=(-1,N)[v],stderr=(-2,N)[v])).returncode)!=0:
+            if env.is_dir():i("shutil").rmtree(env)
+            ew(f"pip had non zero exit ({rc})\n{p.stdout}\n");sys.exit(rc)
+        w(env/"viv-info.json",i("json").dumps(
+            {"created":s(i("datetime").datetime.today()),"id":_id,"spec":spec,"exe":exe}))
+    sys.path=[p for p in (*sys.path,s(*(env/"lib").glob("py*/si*")))if p!=i("site").USER_SITE]
+    return env"""  # noqa
+
+    def noqa(self, txt: str) -> str:
+        max_length = max(map(len, txt.splitlines()))
+        return "\n".join((f"{line:{max_length}} # noqa" for line in txt.splitlines()))
+
+    def _use_str(self, spec: List[str], standalone: bool = False) -> str:
+        spec_str = ", ".join(f'"{req}"' for req in spec)
+        if standalone:
+            return f"""_viv_use({fill(spec_str,width=90,subsequent_indent="    ",)})"""
+        else:
+            return f"""__import__("viv").use({spec_str})"""
+
+    def standalone(self, spec: List[str]) -> str:
+        func_use = self.noqa(
+            "\n".join((self._standalone_func, self._use_str(spec, standalone=True)))
+        )
+        return f"""
+# see `python3 <(curl -fsSL gh.dayl.in/viv/viv.py) --help`
+# <<<<< auto-generated by viv (v{__version__})
+# fmt: off
+{func_use}
+# fmt: on
+# >>>>> code golfed with <3
+"""
+
+    def _rel_import(self, local_source: Optional[Path]) -> str:
+        if not local_source:
+            raise ValueError("local source must exist")
+
+        path_to_viv = path_to_viv = str(
+            local_source.resolve().absolute().parent.parent
+        ).replace(str(Path.home()), "~")
+        return (
+            """__import__("sys").path.append(__import__("os")"""
+            f""".path.expanduser("{path_to_viv}"))  # noqa"""
+        )
+
+    def _absolute_import(self, local_source: Optional[Path]) -> str:
+        if not local_source:
+            raise ValueError("local source must exist")
+
+        path_to_viv = local_source.resolve().absolute().parent.parent
+        return f"""__import__("sys").path.append("{path_to_viv}")  # noqa"""
+
+    def frozen_import(
+        self, path: str, local_source: Optional[Path], spec: List[str]
+    ) -> str:
+        if path == "abs":
+            imports = self._absolute_import(local_source)
+        elif path == "rel":
+            imports = self._rel_import(local_source)
+        else:
+            imports = ""
+        return f"""\
+{imports}
+{self.noqa(self._use_str(spec))}
+"""
+
+    def shim(
+        self,
+        path: str,
+        local_source: Optional[Path],
+        standalone: bool,
+        spec: List[str],
+        bin: str,
+    ) -> str:
+        if standalone:
+            imports = "\n".join(
+                ("# fmt: off", self.noqa(self._standalone_func), "# fmt: on")
+            )
+        elif path == "abs":
+            imports = self._absolute_import(local_source)
+        elif path == "rel":
+            imports = self._rel_import(local_source)
+        else:
+            imports = ""
+        return f"""\
+#!/usr/bin/env python3
+{imports}
+import subprocess
+import sys
+
+if __name__ == "__main__":
+    vivenv = {self.noqa(self._use_str(spec, standalone))}
+    sys.exit(subprocess.run([vivenv / "bin" / "{bin}", *sys.argv[1:]]).returncode)
+"""
+
+    def update(
+        self, src: Optional[Path], cli: Path, local_version: str, next_version: str
+    ) -> str:
+        return f"""
+  Update source at {a.green}{src}{a.end}
+  Symlink {a.bold}{src}{a.end} to {a.bold}{cli}{a.end}
+  Version {a.bold}{local_version}{a.end} -> {a.bold}{next_version}{a.end}
+
+"""
+
+    def install(self, src: Path, cli: Path) -> str:
+        return f"""
+  Install viv.py to {a.green}{src}{a.end}
+  Symlink {a.bold}{src}{a.end} to {a.bold}{cli}{a.end}
+
+"""
+
+    def show(
+        self, cli: Optional[Path | str], running: Path, local: Optional[Path | str]
+    ) -> str:
+        return (
+            "\n".join(
+                f"  {a.bold}{k}{a.end}: {v}"
+                for k, v in (
+                    ("Version", __version__),
+                    ("CLI", cli),
+                    ("Running Source", running),
+                    ("Local Source", local),
+                )
+            )
+            + "\n"
+        )
+
+
+t = Template()
+
+
 # TODO: convet the below functions into a proper file/stream logging interface
 def echo(
     msg: str, style: str = "magenta", newline: bool = True, fd: TextIO = sys.stderr
@@ -680,103 +853,10 @@ def get_venvs() -> Dict[str, ViVenv]:
     return vivenvs
 
 
-# TODO: make a template class?
-
-SYS_PATH_TEMPLATE = """__import__("sys").path.append("{path_to_viv}")  # noqa"""
-REL_SYS_PATH_TEMPLATE = (
-    """__import__("sys").path.append(__import__("os")"""
-    """.path.expanduser("{path_to_viv}"))  # noqa"""
-)
-IMPORT_TEMPLATE = """__import__("viv").use({spec})  # noqa"""
-
-STANDALONE_TEMPLATE = r"""
-# <<<<< auto-generated by viv (v{version})
-# see `python3 <(curl -fsSL gh.dayl.in/viv/viv.py) --help`
-# fmt: off
-{func}
-# fmt: on
-# >>>>> code golfed with <3
-"""  # noqa
-
-STANDALONE_TEMPLATE_FUNC = r"""def _viv_use(*pkgs, track_exe=False, name=""):
-    T,F=True,False;i,s,m,e,spec=__import__,str,map,lambda x: T if x else F,[*pkgs]
-    if not {*m(type,pkgs)}=={s}: raise ValueError(f"spec: {pkgs} is invalid")
-    ge,sys,P,ew=i("os").getenv,i("sys"),i("pathlib").Path,i("sys").stderr.write
-    (cache:=(P(ge("XDG_CACHE_HOME",P.home()/".cache"))/"viv"/"venvs")).mkdir(parents=T,exist_ok=T)
-    ((sha256:=i("hashlib").sha256()).update((s(spec)+
-     (((exe:=("N/A",s(P(i("sys").executable).resolve()))[e(track_exe)])))).encode()))
-    if ((env:=cache/(name if name else (_id:=sha256.hexdigest())))
-        not in cache.glob("*/")) or ge("VIV_FORCE"):
-        v=e(ge("VIV_VERBOSE"));ew(f"generating new vivenv -> {env.name}\n")
-        i("venv").EnvBuilder(with_pip=T,clear=T).create(env)
-        with (env/"pip.conf").open("w") as f:f.write("[global]\ndisable-pip-version-check=true")
-        if (p:=i("subprocess").run([env/"bin"/"pip","install","--force-reinstall",*spec],text=True,
-            stdout=(-1,None)[v],stderr=(-2,None)[v])).returncode!=0:
-            if env.is_dir():i("shutil").rmtree(env)
-            ew(f"pip had non zero exit ({p.returncode})\n{p.stdout}\n");sys.exit(p.returncode)
-        with (env/"viv-info.json").open("w") as f:
-            i("json").dump({"created":s(i("datetime").datetime.today()),
-            "id":_id,"spec":spec,"exe":exe},f)
-    sys.path = [p for p in (*sys.path,s(*(env/"lib").glob("py*/si*"))) if p!=i("site").USER_SITE]
-    return env
-"""  # noqa
-
-SHOW_TEMPLATE = f"""
-  {a.style('Version', 'bold')}: {{version}}
-  {a.style('CLI', 'bold')}: {{cli}}
-  {a.style('Running Source', 'bold')}: {{running_src}}
-  {a.style('Local Source', 'bold')}: {{local_src}}
-"""
-
-INSTALL_TEMPLATE = f"""
-  Install viv.py to {a.green}{{src_location}}{a.end}
-  Symlink {a.bold}{{src_location}}{a.end} to {a.bold}{{cli_location}}{a.end}
-
-"""
-
-UPDATE_TEMPLATE = f"""
-  Update source at {a.green}{{src_location}}{a.end}
-  Symlink {a.bold}{{src_location}}{a.end} to {a.bold}{{cli_location}}{a.end}
-  Version {a.bold}{{local_version}}{a.end} -> {a.bold}{{next_version}}{a.end}
-
-"""
-
-SHIM_TEMPLATE = """\
-#!/usr/bin/env python3
-
-{imports}
-import subprocess
-import sys
-
-if __name__ == "__main__":
-    vivenv = {use}
-    sys.exit(subprocess.run([vivenv / "bin" / "{bin}", *sys.argv[1:]]).returncode)
-"""
-
-DESCRIPTION = f"""
-
-{a.tagline()}
-to create/activate a vivenv:
-- from command line: `{a.style("viv -h","bold")}`
-- within python script: {a.style('__import__("viv").use("typer", "rich-click")','bold')}
-"""
-
-
-def noqa(txt: str) -> str:
-    max_length = max(map(len, txt.splitlines()))
-    return "\n".join((f"{line:{max_length}} # noqa" for line in txt.splitlines()))
-
-
-def spec_to_import(spec: List[str]) -> None:
-    spec_str = ", ".join(f'"{pkg}"' for pkg in spec)
-    sys.stdout.write(IMPORT_TEMPLATE.format(spec=spec_str) + "\n")
-
-
 def combined_spec(reqs: List[str], requirements: Path) -> List[str]:
     if requirements:
         with requirements.open("r") as f:
             reqs += f.readlines()
-
     return reqs
 
 
@@ -803,66 +883,6 @@ def resolve_deps(args: Namespace) -> List[str]:
     return resolved_spec.splitlines()
 
 
-def generate_import(
-    args: Namespace,
-) -> None:
-    spec = resolve_deps(args)
-    if args.keep:
-        # re-create env again since path's are hard-coded
-        vivenv = ViVenv(spec)
-
-        if vivenv.name not in [d.name for d in c.venvcache.iterdir()] or os.getenv(
-            "VIV_FORCE"
-        ):
-            vivenv.create()
-            vivenv.install_pkgs()
-            vivenv.dump_info(write=True)
-
-        else:
-            echo("re-using existing vivenv")
-
-    echo("see below for import statements\n")
-
-    if args.standalone:
-        sys.stdout.write(
-            STANDALONE_TEMPLATE.format(
-                version=__version__,
-                func=noqa(
-                    STANDALONE_TEMPLATE_FUNC
-                    + "_viv_use("
-                    + fill(
-                        ", ".join(f'"{pkg}"' for pkg in spec),
-                        width=100,
-                        subsequent_indent="    ",
-                    )
-                    + ")"
-                ),
-            )
-            + "\n"
-        )
-        return
-
-    if args.path:
-        if args.path == "abs":
-            sys.stdout.write(
-                SYS_PATH_TEMPLATE.format(
-                    path_to_viv=Path(__file__).resolve().absolute().parent.parent
-                )
-                + "\n"
-            )
-        elif args.path == "rel":
-            sys.stdout.write(
-                REL_SYS_PATH_TEMPLATE.format(
-                    path_to_viv=str(
-                        Path(__file__).resolve().absolute().parent.parent
-                    ).replace(str(Path.home()), "~")
-                )
-                + "\n"
-            )
-
-    spec_to_import(spec)
-
-
 def fetch_source(reference: str) -> str:
     try:
         r = urlopen(
@@ -929,21 +949,12 @@ class Viv:
         else:
             self.git = False
 
-    def _check_local_source(self, args: Namespace) -> None:
-        if not self.local_source and not (args.standalone or args.path):
-            warn(
-                "failed to find local copy of `viv` "
-                "make sure to add it to your PYTHONPATH "
-                "or consider using --path/--standalone"
-            )
-
     def _match_vivenv(self, name_id: str) -> ViVenv:  # type: ignore[return]
-        # TODO: improve matching algorithm to favor names over id's
         matches: List[ViVenv] = []
         for k, v in self.vivenvs.items():
             if name_id == k or v.name == name_id:
                 matches.append(v)
-            elif k.startswith(name_id) or v.id.startswith(name_id):
+            elif k.startswith(name_id) or (v.id.startswith(name_id) and v.id == v.name):
                 matches.append(v)
             elif v.name.startswith(name_id):
                 matches.append(v)
@@ -978,16 +989,29 @@ class Viv:
     def freeze(self, args: Namespace) -> None:
         """create import statement from package spec"""
 
-        self._check_local_source(args)
+        spec = resolve_deps(args)
+        if args.keep:
+            # re-create env again since path's are hard-coded
+            vivenv = ViVenv(spec)
 
-        if not args.reqs:
+            if not vivenv.exists or os.getenv("VIV_FORCE"):
-            error("must specify a requirement", code=1)
+                vivenv.create()
-        if args.path and args.standalone:
+                vivenv.install_pkgs()
-            error("-p/--path and -s/--standalone are mutually exclusive", code=1)
+                vivenv.dump_info(write=True)
 
-        generate_import(
+            else:
-            args,
+                echo("re-using existing vivenv")
-        )
+
+        echo("see below for import statements\n")
+
+        if args.standalone:
+            sys.stdout.write(t.standalone(spec))
+            return
+
+        if args.path and not self.local_source:
+            error("No local viv found to import from", code=1)
+
+        sys.stdout.write(t.frozen_import(args.path, self.local_source, spec))
 
     def list(self, args: Namespace) -> None:
         """list all vivenvs"""
@@ -1012,7 +1036,7 @@ class Viv:
             a.table(rows)
 
     def exe(self, args: Namespace) -> None:
-        """run python/pip in vivenv"""
+        """run python/pip in existing vivenv"""
 
         vivenv = self._match_vivenv(args.vivenv)
 
@@ -1062,6 +1086,10 @@ class Viv:
             f'{src.relative_to(Path.home()).parent}"\n'
         )
 
+    def _get_new_version(self, ref: str) -> Tuple[str, str]:
+        sys.path.append(str(c.srccache))
+        return (sha256 := fetch_source(ref)), __import__(sha256).__version__
+
     def manage(self, args: Namespace) -> None:
         """manage viv itself"""
 
@@ -1074,31 +1102,15 @@ class Viv:
             else:
                 echo("Current:")
                 sys.stderr.write(
-                    SHOW_TEMPLATE.format(
+                    t.show(
-                        version=__version__,
                         cli=shutil.which("viv"),
-                        running_src=self.running_source,
+                        running=self.running_source,
-                        local_src=self.local_source,
+                        local=self.local_source,
                     )
                 )
 
         elif args.cmd == "update":
-            if not self.local_source:
+            sha256, next_version = self._get_new_version(args.ref)
-                error(
-                    a.style("viv manage update", "bold")
-                    + " should be used with an exisiting installation",
-                    1,
-                )
-
-            if self.git:
-                error(
-                    a.style("viv manage update", "bold")
-                    + " shouldn't be used with a git-based installation",
-                    1,
-                )
-            sha256 = fetch_source(args.ref)
-            sys.path.append(str(c.srccache))
-            next_version = __import__(sha256).__version__
 
             if self.local_version == next_version:
                 echo(f"no change between {args.ref} and local version")
@@ -1106,12 +1118,7 @@ class Viv:
 
             if confirm(
                 "Would you like to perform the above installation steps?",
-                UPDATE_TEMPLATE.format(
+                t.update(self.local_source, args.cli, self.local_version, next_version),
-                    src_location=self.local_source,
-                    local_version=self.local_version,
-                    cli_location=args.cli,
-                    next_version=next_version,
-                ),
             ):
                 self._install_local_src(
                     sha256,
@@ -1122,19 +1129,8 @@ class Viv:
                 )
 
         elif args.cmd == "install":
-            if self.local_source:
+            sha256, downloaded_version = self._get_new_version(args.ref)
-                error(f"found existing viv installation at {self.local_source}")
-                echo(
-                    "use "
-                    + a.style("viv manage update", "bold")
-                    + " to modify current installation.",
-                    style="red",
-                )
-                sys.exit(1)
 
-            sha256 = fetch_source(args.ref)
-            sys.path.append(str(c.srccache))
-            downloaded_version = __import__(sha256).__version__
             echo(f"Downloaded version: {downloaded_version}")
 
             # TODO: see if file is actually where
@@ -1142,12 +1138,10 @@ class Viv:
 
             if confirm(
                 "Would you like to perform the above installation steps?",
-                INSTALL_TEMPLATE.format(
+                t.install(args.src, args.cli),
-                    src_location=args.src,
-                    cli_location=args.cli,
-                ),
             ):
                 self._install_local_src(sha256, args.src, args.cli)
+
         elif args.cmd == "purge":
             to_remove = []
             if c._cache.is_dir():
@@ -1193,11 +1187,6 @@ class Viv:
           viv shim black
           viv shim yartsu -o ~/bin/yartsu --standalone
         """
-        self._check_local_source(args)
-
-        if not args.reqs:
-            error("please specify at lease one dependency", code=1)
-
         default_bin, bin = self._pick_bin(args)
         output = (
             c.binparent / default_bin if not args.output else args.output.absolute()
@@ -1211,50 +1200,24 @@ class Viv:
         else:
             spec = combined_spec(args.reqs, args.requirements)
 
-        spec_str = ", ".join(f'"{req}"' for req in spec)
-        if args.standalone:
-            imports = STANDALONE_TEMPLATE.format(
-                version=__version__, func=noqa(STANDALONE_TEMPLATE_FUNC)
-            )
-            use = f"_viv_use({spec_str})"
-        elif args.path:
-            if not self.local_source:
-                error("No local viv found to import from", code=1)
-            else:
-                imports = (
-                    REL_SYS_PATH_TEMPLATE.format(
-                        path_to_viv=str(
-                            self.local_source.resolve().absolute().parent.parent
-                        ).replace(str(Path.home()), "~")
-                    )
-                    if args.path == "abs"
-                    else SYS_PATH_TEMPLATE.format(
-                        path_to_viv=self.local_source.resolve().absolute().parent.parent
-                    )
-                )
-                use = IMPORT_TEMPLATE.format(spec=spec_str)
-        else:
-            imports = ""
-            use = IMPORT_TEMPLATE.format(spec=spec_str)
-
         if confirm(
             f"Write shim for {a.style(bin,'bold')} to {a.style(output,'green')}?"
         ):
             with output.open("w") as f:
-                f.write(SHIM_TEMPLATE.format(imports=imports, use=use, bin=bin))
+                f.write(
+                    t.shim(args.path, self.local_source, args.standalone, spec, bin)
+                )
 
             make_executable(output)
 
     def run(self, args: Namespace) -> None:
         """\
-        run an app w/ an on-demand venv
+        run an app with an on-demand venv
 
         examples:
-          viv r pycowsay -- "Viv isn't venv\!"
+          viv r pycowsay -- "viv isn't venv\!"
           viv r rich -b python -- -m rich
         """
-        if not args.reqs:
-            error("please specify at lease one dependency", code=1)
 
         _, bin = self._pick_bin(args)
         spec = combined_spec(args.reqs, args.requirements)
@@ -1302,10 +1265,53 @@ class Viv:
 
         return parser
 
+    def _validate_args(self, args):
+        if args.func.__name__ in ("freeze", "shim", "run"):
+            if not args.reqs:
+                error("must specify a requirement", code=1)
+        if args.func.__name__ in ("freeze", "shim"):
+            if not self.local_source and not (args.standalone or args.path):
+                warn(
+                    "failed to find local copy of `viv` "
+                    "make sure to add it to your PYTHONPATH "
+                    "or consider using --path/--standalone"
+                )
+
+            if args.path and not self.local_source:
+                error("No local viv found to import from", code=1)
+
+            if args.path and args.standalone:
+                error("-p/--path and -s/--standalone are mutually exclusive", code=1)
+
+        if args.func.__name__ == "manage":
+            if args.cmd == "install" and self.local_source:
+                error(f"found existing viv installation at {self.local_source}")
+                echo(
+                    "use "
+                    + a.style("viv manage update", "bold")
+                    + " to modify current installation.",
+                    style="red",
+                )
+                sys.exit(1)
+            if args.cmd == "update":
+                if not self.local_source:
+                    error(
+                        a.style("viv manage update", "bold")
+                        + " should be used with an exisiting installation",
+                        1,
+                    )
+
+                if self.git:
+                    error(
+                        a.style("viv manage update", "bold")
+                        + " shouldn't be used with a git-based installation",
+                        1,
+                    )
+
     def cli(self) -> None:
         """cli entrypoint"""
 
-        parser = ArgumentParser(prog=self.name, description=DESCRIPTION)
+        parser = ArgumentParser(prog=self.name, description=t.description)
         parser.add_argument(
             "-V",
             "--version",
@@ -1500,6 +1506,7 @@ class Viv:
             args = parser.parse_args()
             args.rest = []
 
+        self._validate_args(args)
         args.func(
             args,
         )