"""Sync generated TypeScript protocol surfaces from canonical manifests."""

from __future__ import annotations

import argparse
import json
from pathlib import Path
from typing import Any

from .events import load_event_manifest
from .slash_commands import load_slash_command_manifest

ROOT = Path(__file__).resolve().parents[2]
TUI_PROTOCOL_PATH = ROOT / "apps" / "tui" / "src" / "bridge" / "protocol.ts"
TUI_REGISTRY_PATH = ROOT / "apps" / "tui" / "src" / "commands" / "registry.ts"

EVENTS_BEGIN = "// <openspace-protocol-events:generated>"
EVENTS_END = "// </openspace-protocol-events:generated>"
EVENT_MAP_BEGIN = "// <openspace-protocol-event-data-map:generated>"
EVENT_MAP_END = "// </openspace-protocol-event-data-map:generated>"
COMMANDS_BEGIN = "// <openspace-slash-commands:generated>"
COMMANDS_END = "// </openspace-slash-commands:generated>"


def _quote(value: str) -> str:
    return json.dumps(value)


def _ts_string_array(values: list[str], *, indent: str = "  ") -> str:
    if not values:
        return "[]"
    lines = ["["]
    lines.extend(f"{indent}{_quote(value)}," for value in values)
    lines.append("]")
    return "\n".join(lines)


def _ts_type_union(values: list[str], *, indent: str = "  ") -> str:
    if not values:
        return "never"
    return "\n".join(f"{indent}| {_quote(value)}" for value in values)


def _unique(values: list[str]) -> list[str]:
    seen: set[str] = set()
    result: list[str] = []
    for value in values:
        if value in seen:
            continue
        seen.add(value)
        result.append(value)
    return result


def _replace_section(source: str, begin: str, end: str, rendered: str) -> str:
    start = source.find(begin)
    finish = source.find(end)
    if start == -1 or finish == -1 or finish < start:
        raise RuntimeError(f"missing generated section markers {begin!r} / {end!r}")
    finish += len(end)
    return source[:start] + rendered.rstrip() + source[finish:]


def _command_literal(command: dict[str, Any]) -> dict[str, Any]:
    handler = str(command["handler"])
    literal: dict[str, Any] = {
        "handler": handler,
        "availability": [handler],
        "implemented": bool(command.get("implemented", True)),
        "name": str(command["name"]),
        "description": str(command["description"]),
        "summary": str(command["summary"]),
        "usage": str(command["usage"]),
        "category": str(command["category"]),
    }
    aliases = [str(alias) for alias in command.get("aliases", [])]
    if aliases:
        literal["aliases"] = aliases
    args = command.get("args", [])
    if args:
        literal["args"] = [
            {
                "name": str(arg["name"]),
                "required": bool(arg["required"]),
                "description": str(arg["description"]),
            }
            for arg in args
        ]
    if not bool(command.get("tui_visible", True)):
        literal["isHidden"] = True
    return literal


def render_protocol_events_section() -> str:
    manifest = load_event_manifest()
    tui_to_core = [str(value) for value in manifest["tui_to_core"]]
    core_to_tui = [str(value) for value in manifest["core_to_tui"]]
    all_events = _unique(tui_to_core + core_to_tui)
    policy = manifest.get("unknown_event", {})
    warning_event = str(policy.get("event") or "notification")
    warning_level = str(policy.get("level") or "warn")
    warning_title = str(policy.get("title") or "Protocol warning")

    return "\n".join(
        [
            EVENTS_BEGIN,
            "// Generated by python -m openspace.protocol.codegen --write",
            "export const TUI_TO_CORE_MSG_TYPES = "
            + _ts_string_array(tui_to_core)
            + " as const;",
            "",
            "export const CORE_TO_TUI_MSG_TYPES = "
            + _ts_string_array(core_to_tui)
            + " as const;",
            "",
            "export type TuiToCoreMsgType = typeof TUI_TO_CORE_MSG_TYPES[number];",
            "",
            "export type CoreToTuiMsgType = typeof CORE_TO_TUI_MSG_TYPES[number];",
            "",
            "export type EventType = TuiToCoreMsgType | CoreToTuiMsgType;",
            "",
            "const KNOWN_EVENT_TYPES: ReadonlySet<string> = new Set("
            + _ts_string_array(all_events)
            + ");",
            "",
            "export function isKnownEventType(value: string): value is EventType {",
            "  return KNOWN_EVENT_TYPES.has(value);",
            "}",
            "",
            "export function makeProtocolWarningMessage(",
            "  eventType: string,",
            "  reason: string,",
            "): IPCMessage<\"notification\"> {",
            "  return {",
            f"    type: {_quote(warning_event)},",
            "    data: {",
            f"      level: {_quote(warning_level)},",
            f"      title: {_quote(warning_title)},",
            "      message: `${reason}: ${eventType}`,",
            "      event_type: eventType,",
            "    },",
            "  };",
            "}",
            EVENTS_END,
        ]
    )


def render_protocol_event_map_section() -> str:
    manifest = load_event_manifest()
    payload_types = manifest["payload_types"]
    lines = [
        EVENT_MAP_BEGIN,
        "// Generated by python -m openspace.protocol.codegen --write",
        "export type EventDataMap = {",
    ]
    for event_type in _unique([*manifest["tui_to_core"], *manifest["core_to_tui"]]):
        lines.append(f"  {event_type}: {payload_types[event_type]};")
    lines.extend(["};", EVENT_MAP_END])
    return "\n".join(lines)


def render_registry_section() -> str:
    manifest = load_slash_command_manifest()
    commands = manifest["commands"]
    categories = manifest.get("categories", {})
    command_names = [str(command["name"]) for command in commands]
    category_names = [str(name) for name in categories]

    registry_json = json.dumps(
        [_command_literal(command) for command in commands],
        indent=2,
        ensure_ascii=False,
    )
    category_json = json.dumps(categories, indent=2, ensure_ascii=False)

    return "\n".join(
        [
            COMMANDS_BEGIN,
            "// Generated by python -m openspace.protocol.codegen --write",
            "export type SlashCommandName =",
            _ts_type_union(command_names)
            + ";",
            "",
            "export type SlashCommandCategory =",
            _ts_type_union(category_names)
            + ";",
            "",
            "export type SlashCommandArg = {",
            "  name: string;",
            "  required: boolean;",
            "  description: string;",
            "};",
            "",
            "export type SlashCommandDefinition = Command & {",
            "  name: SlashCommandName;",
            "  summary: string;",
            "  usage: string;",
            "  category: SlashCommandCategory;",
            "  args?: SlashCommandArg[];",
            "  hidden?: boolean;",
            "  implemented?: boolean;",
            "};",
            "",
            "export type ParsedSlashCommand = SlashCommandData & {",
            "  args: string[];",
            "  raw: string;",
            "  definition: SlashCommandDefinition | null;",
            "  isSupported: boolean;",
            "};",
            "",
            "const SLASH_COMMAND_REGISTRY: readonly SlashCommandDefinition[] = "
            + registry_json
            + " as const;",
            "",
            "const CATEGORY_LABELS: Record<SlashCommandCategory, string> = "
            + category_json
            + ";",
            COMMANDS_END,
        ]
    )


def render_tui_protocol(source: str) -> str:
    source = _replace_section(
        source,
        EVENTS_BEGIN,
        EVENTS_END,
        render_protocol_events_section(),
    )
    return _replace_section(
        source,
        EVENT_MAP_BEGIN,
        EVENT_MAP_END,
        render_protocol_event_map_section(),
    )


def render_tui_registry(source: str) -> str:
    return _replace_section(
        source,
        COMMANDS_BEGIN,
        COMMANDS_END,
        render_registry_section(),
    )


def sync_generated_files(*, check: bool) -> list[Path]:
    targets = {
        TUI_PROTOCOL_PATH: render_tui_protocol(TUI_PROTOCOL_PATH.read_text(encoding="utf-8")),
        TUI_REGISTRY_PATH: render_tui_registry(TUI_REGISTRY_PATH.read_text(encoding="utf-8")),
    }

    changed: list[Path] = []
    for path, rendered in targets.items():
        current = path.read_text(encoding="utf-8")
        if current == rendered:
            continue
        changed.append(path)
        if not check:
            path.write_text(rendered, encoding="utf-8")
    return changed


def main(argv: list[str] | None = None) -> int:
    parser = argparse.ArgumentParser(
        description="Sync generated TypeScript protocol files from OpenSpace manifests."
    )
    mode = parser.add_mutually_exclusive_group()
    mode.add_argument("--check", action="store_true", help="fail if generated files are stale")
    mode.add_argument("--write", action="store_true", help="update generated files")
    args = parser.parse_args(argv)

    check = not args.write
    changed = sync_generated_files(check=check)
    if not changed:
        print("protocol generated files are up to date")
        return 0

    for path in changed:
        print(path.relative_to(ROOT).as_posix())
    if check:
        print("generated files are stale; run python -m openspace.protocol.codegen --write")
        return 1
    return 0


if __name__ == "__main__":
    raise SystemExit(main())