Add Fish module

pasch/modules/__init__.py

@@ -1,9 +1,11 @@
 from .echo import Echo
 from .files import Files
+from .fish import Fish
 from .pacman import Pacman
 
 __all__: list[str] = [
     "Echo",
     "Files",
+    "Fish",
     "Pacman",
 ]

pasch/modules/fish.py

@@ -0,0 +1,107 @@
+import os
+from dataclasses import dataclass
+
+from pasch.file.text import TextFile
+from pasch.modules.files import Files
+from pasch.modules.pacman import Pacman
+from pasch.orchestrator import Module, Orchestrator
+from pasch.util import prompt, run_execute
+
+
+def escape(s: str) -> str:
+    # The only meaningful escape sequences in single quotes are `\'`, which
+    # escapes a single quote and `\\`, which escapes the backslash symbol.
+    ESCAPES = {"'": "\\'", "\\": "\\\\"}
+    escaped = "".join(ESCAPES.get(c, c) for c in s)
+    return f"'{escaped}'"
+
+
+@dataclass
+class Raw:
+    string: str
+
+
+type FishStr = str | Raw
+
+
+def fescape(s: FishStr) -> str:
+    if isinstance(s, Raw):
+        return s.string
+    return escape(s)
+
+
+class Fish(Module):
+    def __init__(
+        self,
+        orchestrator: Orchestrator,
+        files: Files,
+        pacman: Pacman,
+    ) -> None:
+        super().__init__(orchestrator)
+        self._files = files
+        self._pacman = pacman
+
+        self.path: list[FishStr] = []
+        self.abbrs: dict[str, FishStr] = {}
+        self.env_vars: dict[str, FishStr] = {}
+
+        self.commands: list[str] = []
+        self.interactive_commands: list[str] = []
+
+    def add_to_path(self, value: FishStr) -> None:
+        self.path.append(value)
+
+    def add_abbr(self, name: str, replacement: FishStr) -> None:
+        self.abbrs[name] = replacement
+
+    def add_env_var(self, name: str, value: FishStr) -> None:
+        self.env_vars[name] = value
+
+    def add_command(self, command: str) -> None:
+        self.commands.append(command)
+
+    def add_interactive(self, command: str) -> None:
+        self.interactive_commands.append(command)
+
+    def configure(self) -> None:
+        file = TextFile()
+        file.tag(comment="#")
+
+        # Commands set by the user should always appear after generated commands
+        commands = self.commands
+        interactive_commands = self.interactive_commands
+        self.commands = []
+        self.interactive_commands = []
+
+        if self.path:
+            segments = " ".join(fescape(s) for s in self.path)
+            self.add_command(f"set PATH $PATH {segments}")
+        for name, replacement in sorted(self.abbrs.items()):
+            self.add_interactive(f"'abbr' {escape(name)} {fescape(replacement)}")
+        for name, value in sorted(self.env_vars.items()):
+            self.add_command(f"set -gx {escape(name)} {fescape(value)}")
+
+        self.commands.extend(commands)
+        self.interactive_commands.extend(interactive_commands)
+
+        for command in self.commands:
+            file.append(command)
+        if self.commands and self.interactive_commands:
+            file.append("")
+        if self.interactive_commands:
+            file.append("if status is-interactive")
+            for command in self.interactive_commands:
+                file.append(f"  {command}")
+            file.append("end")
+
+        self._files.add(".config/fish/config.fish", file)
+        self._pacman.install("fish")
+
+    def execute(self) -> None:
+        shell = os.environ.get("SHELL")
+        if shell == "/usr/bin/fish":
+            return
+        fix = prompt("Your shell is not fish. Set it to fish?", default=False)
+        if not fix:
+            return
+        run_execute("sudo", "usermod", "--shell", "/usr/bin/fish", self.o.user)