"""xros_shell.py — the spatial shell: a command interpreter over the shared world.

This is the "terminal" half of the spatial OS. The terminal (in the Quest app)
sends a command string; the shell parses it, mutates the shared WorldState, and
returns text output. World mutations are broadcast to every connected client by
the server, so a `spawn panel` typed in the terminal makes a panel appear in the
spatial scene for everyone.

Commands:
  help                          list commands
  ls | list                     list every object in the world
  spawn <type> [x y z] [opts]   create an object (panel, cube, ...)
  move <id> x y z               move an object
  rm <id> | remove <id>         remove an object
  clear                         remove every object
  gen <description>             generative UI (stub: rule-based panel generator)

The `gen` command is the stub for the generative-UI layer: it maps a natural-
language description to a panel type via keyword rules, so the concept works
end to end before a real LLM is wired in.
"""

from __future__ import annotations

import shlex
from typing import List, Optional, Tuple

from xros_world import Pose, WorldState

HELP_TEXT = """spatial shell commands:
  help
  ls | list
  spawn <type> [x y z] [--title T] [--color C]
  move <id> x y z
  rm <id> | remove <id>
  clear
  gen <description>   (generative UI — stub)
"""

# Keyword -> panel type rules for the generative-UI stub.
GEN_RULES: List[Tuple[List[str], str]] = [
    (["clock", "time", "watch"], "clock"),
    (["note", "memo", "remind", "remember"], "note"),
    (["todo", "task", "checklist", "list"], "todo"),
    (["chart", "graph", "plot", "bar"], "chart"),
    (["image", "photo", "picture", "pic"], "image"),
    (["video", "player", "movie"], "video"),
    (["map", "location", "where"], "map"),
    (["browser", "web", "search"], "browser"),
]


class SpatialShell:
    def __init__(self, world: WorldState):
        self.world = world

    async def execute(self, command: str) -> str:
        """Run one command line and return its text output."""
        if not command.strip():
            return ""
        try:
            parts = shlex.split(command)
        except ValueError as e:
            return f"error: {e}"
        if not parts:
            return ""
        cmd, args = parts[0].lower(), parts[1:]
        handler = getattr(self, f"cmd_{cmd}", None)
        if handler is None:
            return f"error: unknown command '{cmd}' (try 'help')"
        try:
            return await handler(args)
        except Exception as e:  # surface any error as terminal text, never crash
            return f"error: {e}"

    # ---- commands ------------------------------------------------------

    async def cmd_help(self, args: List[str]) -> str:
        return HELP_TEXT.strip()

    async def cmd_ls(self, args: List[str]) -> str:
        objs = await self.world.snapshot()
        if not objs:
            return "(empty world)"
        lines = []
        for o in objs:
            x, y, z = o["pose"]["position"]
            title = o["properties"].get("title", "")
            lines.append(f"{o['id'][:8]}  {o['type']:<8}  ({x:.1f}, {y:.1f}, {z:.1f})  {title}")
        return "\n".join(lines)

    async def cmd_spawn(self, args: List[str]) -> str:
        type_, pos, opts = self._parse_spawn(args)
        obj = await self.world.spawn(
            type=type_,
            pose=Pose(position=pos),
            properties=opts,
        )
        title = opts.get("title", "")
        return f"spawned {type_} {obj.id[:8]}" + (f" \"{title}\"" if title else "")

    async def cmd_move(self, args: List[str]) -> str:
        if len(args) < 4:
            return "usage: move <id> x y z"
        obj_id, xyz = args[0], [float(a) for a in args[1:4]]
        obj = await self.world.move(obj_id, Pose(position=xyz))
        return f"moved {obj_id[:8]} to ({xyz[0]:.1f}, {xyz[1]:.1f}, {xyz[2]:.1f})"

    async def cmd_rm(self, args: List[str]) -> str:
        if not args:
            return "usage: rm <id>"
        obj = await self.world.remove(args[0])
        return f"removed {args[0][:8]} ({obj.type})"

    async def cmd_clear(self, args: List[str]) -> str:
        objs = await self.world.snapshot()
        for o in objs:
            await self.world.remove(o["id"])
        return f"cleared {len(objs)} object(s)"

    async def cmd_gen(self, args: List[str]) -> str:
        """Generative-UI stub: map a description to a panel via keyword rules."""
        if not args:
            return "usage: gen <description>"
        description = " ".join(args)
        panel_type = self._classify(description)
        obj = await self.world.spawn(
            type="panel",
            pose=Pose(position=[0.0, 0.0, -1.5]),
            properties={"title": description, "panel_type": panel_type},
        )
        return f"generated {panel_type} panel {obj.id[:8]} for \"{description}\""

    # ---- helpers -------------------------------------------------------

    def _parse_spawn(self, args: List[str]) -> Tuple[str, List[float], dict]:
        """Parse `spawn <type> [x y z] [--title T] [--color C]`."""
        if not args:
            raise ValueError("usage: spawn <type> [x y z] [--title T] [--color C]")
        type_ = args[0]
        rest = args[1:]
        pos: List[float] = [0.0, 0.0, -1.5]  # default: 1.5m in front of the user
        opts: dict = {}
        i = 0
        # leading three numbers = position
        nums: List[float] = []
        while i < len(rest) and len(nums) < 3:
            try:
                nums.append(float(rest[i]))
                i += 1
            except ValueError:
                break
        if nums:
            pos = nums
        # remaining --key value pairs
        while i < len(rest):
            if rest[i].startswith("--") and i + 1 < len(rest):
                opts[rest[i][2:]] = rest[i + 1]
                i += 2
            else:
                i += 1
        return type_, pos, opts

    def _classify(self, description: str) -> str:
        low = description.lower()
        for keywords, panel_type in GEN_RULES:
            if any(k in low for k in keywords):
                return panel_type
        return "generic"