from __future__ import annotations

import json
from dataclasses import asdict, dataclass
from pathlib import Path

from aiprocess import ensure_model
from config import Config, load
from desktop import get_desktop_adapter
from recorder import resolve_input_device


@dataclass
class DiagnosticCheck:
    id: str
    ok: bool
    message: str
    hint: str = ""


@dataclass
class DiagnosticReport:
    checks: list[DiagnosticCheck]

    @property
    def ok(self) -> bool:
        return all(check.ok for check in self.checks)

    def to_json(self) -> str:
        payload = {"ok": self.ok, "checks": [asdict(check) for check in self.checks]}
        return json.dumps(payload, ensure_ascii=False, indent=2)


def run_diagnostics(config_path: str | None) -> DiagnosticReport:
    checks: list[DiagnosticCheck] = []
    cfg: Config | None = None

    try:
        cfg = load(config_path or "")
        checks.append(
            DiagnosticCheck(
                id="config.load",
                ok=True,
                message=f"loaded config from {_resolved_config_path(config_path)}",
            )
        )
    except Exception as exc:
        checks.append(
            DiagnosticCheck(
                id="config.load",
                ok=False,
                message=f"failed to load config: {exc}",
                hint=(
                    "open Settings... from Aman tray to save a valid config, or run "
                    "`aman init --force` for automation"
                ),
            )
        )

    checks.extend(_audio_check(cfg))
    checks.extend(_hotkey_check(cfg))
    checks.extend(_injection_backend_check(cfg))
    checks.extend(_provider_check(cfg))
    checks.extend(_model_check(cfg))
    return DiagnosticReport(checks=checks)


def _audio_check(cfg: Config | None) -> list[DiagnosticCheck]:
    if cfg is None:
        return [
            DiagnosticCheck(
                id="audio.input",
                ok=False,
                message="skipped because config failed to load",
                hint="fix config.load first",
            )
        ]
    input_spec = cfg.recording.input
    explicit = input_spec is not None and (not isinstance(input_spec, str) or bool(input_spec.strip()))
    device = resolve_input_device(input_spec)
    if device is None and explicit:
        return [
            DiagnosticCheck(
                id="audio.input",
                ok=False,
                message=f"recording input '{input_spec}' is not resolvable",
                hint="set recording.input to a valid device index or matching device name",
            )
        ]
    if device is None:
        return [
            DiagnosticCheck(
                id="audio.input",
                ok=True,
                message="recording input is unset; default system input will be used",
            )
        ]
    return [DiagnosticCheck(id="audio.input", ok=True, message=f"resolved recording input to device {device}")]


def _hotkey_check(cfg: Config | None) -> list[DiagnosticCheck]:
    if cfg is None:
        return [
            DiagnosticCheck(
                id="hotkey.parse",
                ok=False,
                message="skipped because config failed to load",
                hint="fix config.load first",
            )
        ]
    try:
        desktop = get_desktop_adapter()
        desktop.validate_hotkey(cfg.daemon.hotkey)
    except Exception as exc:
        return [
            DiagnosticCheck(
                id="hotkey.parse",
                ok=False,
                message=f"hotkey '{cfg.daemon.hotkey}' is not available: {exc}",
                hint="pick another daemon.hotkey such as Super+m",
            )
        ]
    return [DiagnosticCheck(id="hotkey.parse", ok=True, message=f"hotkey '{cfg.daemon.hotkey}' is valid")]


def _injection_backend_check(cfg: Config | None) -> list[DiagnosticCheck]:
    if cfg is None:
        return [
            DiagnosticCheck(
                id="injection.backend",
                ok=False,
                message="skipped because config failed to load",
                hint="fix config.load first",
            )
        ]
    return [
        DiagnosticCheck(
            id="injection.backend",
            ok=True,
            message=f"injection backend '{cfg.injection.backend}' is configured",
        )
    ]


def _provider_check(cfg: Config | None) -> list[DiagnosticCheck]:
    if cfg is None:
        return [
            DiagnosticCheck(
                id="provider.runtime",
                ok=False,
                message="skipped because config failed to load",
                hint="fix config.load first",
            )
        ]
    return [
        DiagnosticCheck(
            id="provider.runtime",
            ok=True,
            message=f"stt={cfg.stt.provider}, editor=local_llama_builtin",
        )
    ]


def _model_check(cfg: Config | None) -> list[DiagnosticCheck]:
    if cfg is None:
        return [
            DiagnosticCheck(
                id="model.cache",
                ok=False,
                message="skipped because config failed to load",
                hint="fix config.load first",
            )
        ]
    if cfg.models.allow_custom_models and cfg.models.whisper_model_path.strip():
        path = Path(cfg.models.whisper_model_path)
        if not path.exists():
            return [
                DiagnosticCheck(
                    id="model.cache",
                    ok=False,
                    message=f"custom whisper model path does not exist: {path}",
                    hint="fix models.whisper_model_path or disable custom model paths",
                )
            ]
    try:
        model_path = ensure_model()
        return [DiagnosticCheck(id="model.cache", ok=True, message=f"editor model is ready at {model_path}")]
    except Exception as exc:
        return [
            DiagnosticCheck(
                id="model.cache",
                ok=False,
                message=f"model is not ready: {exc}",
                hint="check internet access and writable cache directory",
            )
        ]


def _resolved_config_path(config_path: str | None) -> Path:
    from constants import DEFAULT_CONFIG_PATH

    return Path(config_path) if config_path else DEFAULT_CONFIG_PATH