from __future__ import annotations

from typing import Any, Dict, Sequence, List, Optional
import shlex
import sys

from cmdlet._shared import Cmdlet, CmdletArg, parse_cmdlet_args
from SYS.logger import log
from result_table import ResultTable
import pipeline as ctx


def _normalize_choice_list(arg_names: Optional[List[str]]) -> List[str]:
    return sorted(set(arg_names or []))


def _examples_for_cmd(name: str) -> List[str]:
    """Return example invocations for a given command (best-effort)."""
    lookup = {
        ".adjective": [
            '.adjective -add "example"',
            '.adjective -delete "example"',
        ],
    }

    key = name.replace("_", "-").lower()
    return lookup.get(key, [])


def _find_cmd_metadata(name: str, metadata: Dict[str, Dict[str, Any]]) -> Optional[Dict[str, Any]]:
    target = name.replace("_", "-").lower()
    for cmd_name, meta in metadata.items():
        if target == cmd_name:
            return meta
        aliases = meta.get("aliases", []) or []
        if target in aliases:
            return meta
    return None


def _render_list(metadata: Dict[str, Dict[str, Any]], filter_text: Optional[str], args: Sequence[str]) -> None:
    table = ResultTable("Help")
    table.set_source_command(".help", list(args))

    items: List[Dict[str, Any]] = []
    needle = (filter_text or "").lower().strip()

    for name in sorted(metadata.keys()):
        meta = metadata[name]
        summary = meta.get("summary", "") or ""
        if needle and needle not in name.lower() and needle not in summary.lower():
            continue

        row = table.add_row()
        row.add_column("Cmd", name)
        aliases = ", ".join(meta.get("aliases", []) or [])
        row.add_column("Aliases", aliases)
        arg_names = [a.get("name") for a in meta.get("args", []) if a.get("name")]
        row.add_column("Args", ", ".join(f"-{a}" for a in arg_names))
        table.set_row_selection_args(len(table.rows) - 1, ["-cmd", name])
        items.append(meta)

    ctx.set_last_result_table(table, items)
    ctx.set_current_stage_table(table)
    from rich_display import stdout_console

    stdout_console().print(table)


def _render_detail(meta: Dict[str, Any], args: Sequence[str]) -> None:
    title = f"Help: {meta.get('name', '') or 'cmd'}"
    table = ResultTable(title)
    table.set_source_command(".help", list(args))

    header_lines: List[str] = []
    summary = meta.get("summary", "")
    usage = meta.get("usage", "")
    aliases = meta.get("aliases", []) or []
    examples = _examples_for_cmd(meta.get("name", ""))
    first_example_tokens: List[str] = []
    first_example_cmd: Optional[str] = None
    if examples:
        try:
            split_tokens = shlex.split(examples[0])
            if split_tokens:
                first_example_cmd = split_tokens[0]
                first_example_tokens = split_tokens[1:]
        except Exception:
            pass

    if summary:
        header_lines.append(summary)
    if usage:
        header_lines.append(f"Usage: {usage}")
    if aliases:
        header_lines.append("Aliases: " + ", ".join(aliases))
    if examples:
        header_lines.append("Examples: " + " | ".join(examples))
    if header_lines:
        table.set_header_lines(header_lines)

    args_meta = meta.get("args", []) or []
    example_text = " | ".join(examples)
    # If we have an example, use it as the source command so @N runs that example
    if first_example_cmd:
        table.set_source_command(first_example_cmd, [])
    if not args_meta:
        row = table.add_row()
        row.add_column("Arg", "(none)")
        row.add_column("Type", "")
        row.add_column("Req", "")
        row.add_column("Description", "")
        row.add_column("Example", example_text)
        if first_example_tokens:
            table.set_row_selection_args(len(table.rows) - 1, first_example_tokens)
    else:
        for arg in args_meta:
            row = table.add_row()
            name = arg.get("name") or ""
            row.add_column("Arg", f"-{name}" if name else "")
            row.add_column("Type", arg.get("type", ""))
            row.add_column("Req", "yes" if arg.get("required") else "")
            desc = arg.get("description", "") or ""
            choices = arg.get("choices", []) or []
            if choices:
                choice_text = f"choices: {', '.join(choices)}"
                desc = f"{desc} ({choice_text})" if desc else choice_text
            row.add_column("Description", desc)
            row.add_column("Example", example_text)
            if first_example_tokens:
                table.set_row_selection_args(len(table.rows) - 1, first_example_tokens)

    ctx.set_last_result_table_overlay(table, [meta])
    ctx.set_current_stage_table(table)
    from rich_display import stdout_console

    stdout_console().print(table)


def _run(result: Any, args: Sequence[str], config: Dict[str, Any]) -> int:
    try:
        import cmdlet_catalog as _catalog

        CMDLET.arg[0].choices = _normalize_choice_list(_catalog.list_cmdlet_names())
        metadata = _catalog.list_cmdlet_metadata()
    except Exception:
        CMDLET.arg[0].choices = []
        metadata = {}

    parsed = parse_cmdlet_args(args, CMDLET)

    filter_text = parsed.get("filter")
    cmd_arg = parsed.get("cmd")

    if cmd_arg:
        target_meta = _find_cmd_metadata(str(cmd_arg), metadata)
        if not target_meta:
            log(f"Unknown command: {cmd_arg}", file=sys.stderr)
            return 1
        _render_detail(target_meta, args)
        return 0

    _render_list(metadata, filter_text, args)
    return 0


CMDLET = Cmdlet(
    name=".help",
    alias=["help", "?"],
    summary="Show cmdlet or detailed help",
    usage=".help [cmd] [-filter text]",
    arg=[
        CmdletArg(
            name="cmd",
            type="string",
            description="Cmdlet name to show detailed help",
            required=False,
            choices=[],
        ),
        CmdletArg(
            name="-filter",
            type="string",
            description="Filter cmdlet by substring",
            required=False,
        ),
    ],
)

CMDLET.exec = _run