import contextlib
import json

import httpx
import questionary
from rich.console import Console
from rich.panel import Panel
from rich.text import Text

from pyra.config.manager import save_config
from pyra.config.schema import GeneralConfig, ProviderConfig, PyraConfig
from pyra.setup.providers import PROVIDERS, Provider, get_provider
from pyra.utils.paths import pyra_home, safe_chmod

console = Console()

_USE_CASE_PLUGINS: dict[str, list[str]] = {
    "Research & web":           ["websearch", "headless_browser"],
    "Development & servers":    ["server_manager", "ssh_tool", "docker_tool"],
    "File management":          ["gdrive", "onedrive", "dropbox_tool"],
    "Communication bots":       ["matrix_bot", "telegram_bot", "signal_bot"],
    "Email":                    ["email"],
    "Productivity & calendars": ["nextcloud"],
}


_DRAFT_FILE = "setup.draft.json"


def _draft_path():
    return pyra_home() / _DRAFT_FILE


def _save_draft(state: dict) -> None:
    path = _draft_path()
    path.write_text(json.dumps(state, indent=2))
    safe_chmod(path, 0o600)


def _load_draft() -> dict | None:
    path = _draft_path()
    if not path.exists():
        return None
    try:
        return json.loads(path.read_text())
    except Exception:
        return None


def _delete_draft() -> None:
    with contextlib.suppress(FileNotFoundError):
        _draft_path().unlink()


def _mark_step_done(state: dict, step: str) -> None:
    state.setdefault("completed_steps", [])
    if step not in state["completed_steps"]:
        state["completed_steps"].append(step)


def _offer_resume(draft: dict) -> bool:
    """Show a summary of the incomplete setup and ask Resume / Start fresh."""
    completed = draft.get("completed_steps", [])
    step_display = {
        "profile":    f"Profile:    {draft.get('user_name', '?')}",
        "provider":   f"Provider:   {draft.get('provider_id', '?')}",
        "model":      f"Model:      {draft.get('model', '?')}",
        "api_key":    "API key:    stored in vault",
        "connection": "Connection: test passed",
    }
    lines = ["[bold]An incomplete setup was found.[/bold]\n"]
    for step, label in step_display.items():
        if step in completed:
            lines.append(f"  [green]✓[/green] {label}")
        else:
            lines.append(f"  [dim]○ {label.split(':')[0].strip()}: pending[/dim]")

    console.print(Panel("\n".join(lines), title="Incomplete setup", border_style="yellow"))
    console.print()

    action = questionary.select(
        "What would you like to do?",
        choices=[
            questionary.Choice("Resume from where you left off", value="resume"),
            questionary.Choice("Start fresh", value="fresh"),
        ],
    ).ask()
    if action is None:
        raise SystemExit(0)
    return action == "resume"


def run_setup() -> None:
    console.print(Panel(
        Text("Welcome to Pyra Setup", justify="center", style="bold cyan"),
        subtitle="Personal AI Assistant",
        border_style="cyan",
    ))
    console.print()

    state: dict = {}
    draft = _load_draft()
    if draft:
        if _offer_resume(draft):
            state = draft
        else:
            _delete_draft()

    try:
        # ── Step 1: profile ────────────────────────────────────────────────
        if "profile" in state.get("completed_steps", []):
            user_name = state["user_name"]
            purpose = state["purpose"]
            use_cases = state["use_cases"]
            console.print(f"  [dim]✓ Profile: {user_name}[/dim]")
        else:
            user_name, purpose, use_cases = _collect_user_profile()
            state.update(user_name=user_name, purpose=purpose, use_cases=use_cases)
            _mark_step_done(state, "profile")
            _save_draft(state)

        # ── Step 2: provider ───────────────────────────────────────────────
        if "provider" in state.get("completed_steps", []):
            provider = get_provider(state["provider_id"])
            console.print(f"  [dim]✓ Provider: {provider.display_name}[/dim]")
        else:
            provider = _choose_provider()
            state.update(provider_id=provider.id)
            _mark_step_done(state, "provider")
            _save_draft(state)

        # ── Step 3: model ──────────────────────────────────────────────────
        if "model" in state.get("completed_steps", []):
            model = state["model"]
            console.print(f"  [dim]✓ Model: {model}[/dim]")
        else:
            model = _choose_model(provider)
            state.update(model=model)
            _mark_step_done(state, "model")
            _save_draft(state)

        # ── Step 4: API key ────────────────────────────────────────────────
        if "api_key" not in state.get("completed_steps", []) and provider.requires_key:
            from pyra.vault.reader import get_key as _get_key
            if not _get_key(provider.id):
                _collect_api_key(provider)
            _mark_step_done(state, "api_key")
            _save_draft(state)

        # ── Step 5: connection test ────────────────────────────────────────
        if "connection" not in state.get("completed_steps", []):
            model = _test_connection(provider, model)
            state["model"] = model
            _mark_step_done(state, "connection")
            _save_draft(state)

        # ── Finalise ───────────────────────────────────────────────────────
        cfg = PyraConfig(
            ai=ProviderConfig(
                provider_id=provider.id,
                model=model,
                base_url=provider.base_url,
            ),
            general=GeneralConfig(user_name=user_name, purpose=purpose),
        )
        save_config(cfg)
        _delete_draft()

        _suggest_plugins(use_cases)

        console.print()
        console.print(Panel(
            f"[green]Setup complete![/green]\n\n"
            f"Provider: [bold]{provider.display_name}[/bold]\n"
            f"Model:    [bold]{model}[/bold]\n\n"
            "Run [bold cyan]pyra chat[/bold cyan] to start talking.",
            border_style="green",
        ))

    except SystemExit:
        if state.get("completed_steps"):
            console.print()
            console.print(
                "  [dim]Setup paused — run [bold]pyra setup[/bold] to resume.[/dim]"
            )
        raise


def _collect_user_profile() -> tuple[str, str, list[str]]:
    console.print("[bold]Let's personalise your setup.[/bold]")
    console.print()

    name = questionary.text("What should Pyra call you?", default="User").ask()
    if name is None:
        raise SystemExit(0)
    name = name.strip() or "User"

    purpose = questionary.text(
        "In one sentence, what will you mainly use Pyra for? (optional)",
    ).ask()
    if purpose is None:
        raise SystemExit(0)
    purpose = purpose.strip()

    use_cases = questionary.checkbox(
        "Which areas interest you? (Space to select, Enter to confirm)",
        choices=list(_USE_CASE_PLUGINS.keys()),
    ).ask()
    if use_cases is None:
        raise SystemExit(0)

    console.print()
    return name, purpose, use_cases or []


def _suggest_plugins(use_cases: list[str]) -> None:
    if not use_cases:
        return

    lines: list[str] = []
    for uc in use_cases:
        plugins = _USE_CASE_PLUGINS.get(uc, [])
        if plugins:
            lines.append(f"[bold]{uc}[/bold]")
            for p in plugins:
                lines.append(f"  pyra plugin install {p}")
    if not lines:
        return

    lines.append("")
    lines.append("[dim]All listed plugins are in development — install when available.[/dim]")

    console.print()
    console.print(Panel(
        "\n".join(lines),
        title="Suggested plugins",
        border_style="dim cyan",
    ))


def _choose_provider() -> Provider:
    local = [p for p in PROVIDERS if p.group == "Local"]
    cloud = [p for p in PROVIDERS if p.group == "Cloud"]

    choices = (
        [questionary.Choice("── Local ──────────────────", disabled=True)]
        + [questionary.Choice(p.display_name, value=p.id) for p in local]
        + [questionary.Choice("── Cloud ──────────────────", disabled=True)]
        + [questionary.Choice(p.display_name, value=p.id) for p in cloud]
    )

    provider_id = questionary.select(
        "Choose your AI provider:",
        choices=choices,
    ).ask()

    if provider_id is None:
        raise SystemExit(0)

    provider = get_provider(provider_id)

    if provider.connectivity_check:
        _check_local_server(provider)
        _show_local_model_status(provider)

    return provider


def _classify_error(exc: Exception) -> tuple[str, str]:
    """Return (short_label, resolution_hint) for a provider or network error."""
    name = type(exc).__name__
    module = type(exc).__module__ or ""
    is_llm = "litellm" in module or "openai" in module

    if is_llm:
        if "AuthenticationError" in name:
            return (
                "Invalid API key",
                "The provider rejected your API key.\n"
                "Double-check it on the provider dashboard and re-enter it.",
            )
        if "NotFoundError" in name:
            return (
                "Model not found",
                "The model name doesn't exist for this provider.\n"
                "Check the exact model identifier on the provider's model list.",
            )
        if "RateLimitError" in name:
            return (
                "Rate limit reached",
                "You've exceeded the provider's request rate.\n"
                "Wait a few seconds and retry.",
            )
        if "ServiceUnavailable" in name:
            return (
                "Service temporarily unavailable",
                "The provider's servers returned a 5xx error.\n"
                "This is usually transient — wait a minute and retry.",
            )
        if "APIConnectionError" in name or "ConnectError" in name:
            return (
                "Cannot reach provider",
                "A network error prevented the connection.\n"
                "Check your internet connection and firewall settings.",
            )
        if "Timeout" in name:
            return (
                "Request timed out",
                "The provider did not respond in time.\n"
                "The service may be overloaded — retry in a moment.",
            )
        if "BadRequestError" in name or "InvalidRequest" in name:
            return (
                "Bad request",
                "The request was rejected — the model name or parameters may be wrong.\n"
                "Verify the exact model identifier.",
            )
        return ("Provider error", str(exc)[:300])

    if "httpx" in module:
        if "ConnectError" in name or "ConnectTimeout" in name:
            return (
                "Server not reachable",
                "Could not connect to the local server.\n"
                "Make sure it is running and listening on the expected address.",
            )
        if "Timeout" in name:
            return (
                "Connection timed out",
                "The local server did not respond in time.\n"
                "It may still be starting up — wait a moment and retry.",
            )
        if "HTTPStatusError" in name:
            code = getattr(getattr(exc, "response", None), "status_code", 0)
            if code == 401:
                return ("Unauthorized (401)", "The server requires credentials that were not provided.")
            if code == 404:
                return ("Endpoint not found (404)", "The API endpoint was not found — check the server version.")
            return (f"HTTP {code}", f"The server returned an unexpected error (HTTP {code}).")

    return ("Unexpected error", str(exc)[:300])


def _check_local_server(provider: Provider) -> None:
    while True:
        console.print(
            f"  Checking connection to [bold]{provider.display_name}[/bold]...", end=" "
        )
        try:
            resp = httpx.get(provider.connectivity_check, timeout=3.0)
            resp.raise_for_status()
            console.print("[green]✓[/green]")
            return
        except Exception as exc:
            label, hint = _classify_error(exc)
            console.print("[yellow]✗[/yellow]")
            console.print()
            console.print(Panel(
                f"[bold yellow]{label}[/bold yellow]\n\n{hint}",
                title="Connection problem",
                border_style="yellow",
            ))
            action = questionary.select(
                "How would you like to proceed?",
                choices=[
                    questionary.Choice("Retry", value="retry"),
                    questionary.Choice(
                        "Continue anyway (model list may be unavailable)", value="continue"
                    ),
                    questionary.Choice("Abort setup", value="abort"),
                ],
            ).ask()
            if action is None or action == "abort":
                raise SystemExit(0)
            if action == "continue":
                return
            # "retry" → loop


def _show_local_model_status(provider: Provider) -> None:
    """Print a one-line status showing which models are currently loaded."""
    models = _fetch_local_models(provider)
    if not models:
        console.print("  [yellow]No model currently loaded[/yellow]")
    elif len(models) == 1:
        console.print(f"  [green]Loaded model:[/green] {models[0]}")
    else:
        names = ", ".join(models)
        console.print(f"  [green]{len(models)} models loaded:[/green] {names}")


def _fetch_local_models(provider: Provider) -> list[str]:
    """Return currently loaded/available models from a local provider's API."""
    if not provider.base_url:
        return []
    try:
        if provider.id == "ollama":
            resp = httpx.get(f"{provider.base_url}/api/tags", timeout=3.0)
            resp.raise_for_status()
            return [m["name"] for m in resp.json().get("models", [])]
        else:
            resp = httpx.get(f"{provider.base_url}/models", timeout=3.0)
            resp.raise_for_status()
            return [m["id"] for m in resp.json().get("data", [])]
    except Exception:
        return []


def _fetch_lmstudio_available_models() -> list[str]:
    """Return all downloaded (not necessarily loaded) models from LM Studio's beta API."""
    try:
        resp = httpx.get("http://localhost:1234/api/v0/models", timeout=3.0)
        resp.raise_for_status()
        return [m["id"] for m in resp.json().get("data", [])]
    except Exception:
        return []


def _load_lmstudio_model(model_id: str) -> bool:
    """Attempt to load a model via LM Studio's beta API. Returns True on success."""
    try:
        resp = httpx.post(
            "http://localhost:1234/api/v0/models/load",
            json={"identifier": model_id},
            timeout=60.0,
        )
        return resp.is_success
    except Exception:
        return False


def _choose_model(provider: Provider) -> str:
    if provider.group != "Local":
        model = questionary.text("Model name:", default=provider.default_model).ask()
        if model is None:
            raise SystemExit(0)
        return model.strip()

    _MANUAL = "__manual__"
    loaded = _fetch_local_models(provider)

    if loaded:
        choices = loaded + [questionary.Choice("── Enter manually ──", value=_MANUAL)]
        selected = questionary.select("Select model:", choices=choices).ask()
        if selected is None:
            raise SystemExit(0)
        if selected != _MANUAL:
            return selected

    elif provider.id == "lmstudio":
        console.print("  [yellow]No model currently loaded in LM Studio.[/yellow]")
        available = _fetch_lmstudio_available_models()
        if available:
            choices = available + [questionary.Choice("── Enter manually ──", value=_MANUAL)]
            selected = questionary.select(
                "Select a downloaded model to load:", choices=choices
            ).ask()
            if selected is None:
                raise SystemExit(0)
            if selected != _MANUAL:
                console.print(f"  Loading [bold]{selected}[/bold]...", end=" ")
                if _load_lmstudio_model(selected):
                    console.print("[green]✓ Loaded[/green]")
                else:
                    console.print(
                        "[yellow]Could not load via API — "
                        "please load the model manually in LM Studio.[/yellow]"
                    )
                return selected
        else:
            console.print(Panel(
                "No models are loaded or downloaded in LM Studio.\n"
                "Open LM Studio → Local Server tab → load a model, then re-run setup.",
                border_style="yellow",
            ))

    else:
        console.print(f"  [yellow]No models found at {provider.base_url}.[/yellow]")

    model = questionary.text("Model name:", default=provider.default_model).ask()
    if model is None:
        raise SystemExit(0)
    return model.strip()


def _collect_api_key(provider: Provider) -> None:
    from pyra.vault.writer import set_key

    console.print(
        f"\n  [dim]API key will be stored in the encrypted vault — never in config.yaml[/dim]"
    )
    key = questionary.password(f"Enter your {provider.display_name} API key:").ask()
    if key is None:
        raise SystemExit(0)
    key = key.strip()
    if not key:
        console.print("[red]No key entered — skipping.[/red]")
        return
    set_key(provider.id, key)
    console.print("  [green]✓ Key stored in vault[/green]")


def _test_connection(provider: Provider, model: str) -> str:
    from pyra.vault.reader import get_key

    while True:
        console.print("\n  Running connection test...", end=" ")
        try:
            import litellm

            api_key = get_key(provider.id) if provider.requires_key else "local"
            kwargs: dict = {
                "model": f"{provider.litellm_prefix}{model}",
                "messages": [{"role": "user", "content": "Reply with exactly: OK"}],
                "max_tokens": 10,
                "api_key": api_key,
            }
            if provider.base_url:
                kwargs["api_base"] = provider.base_url

            litellm.completion(**kwargs)
            console.print("[green]✓ Connection OK[/green]")
            return model

        except Exception as exc:
            label, hint = _classify_error(exc)
            console.print("[red]✗[/red]")
            console.print()
            console.print(Panel(
                f"[bold red]{label}[/bold red]\n\n{hint}",
                title="Test call failed",
                border_style="red",
            ))

            exc_name = type(exc).__name__
            is_auth_error = "AuthenticationError" in exc_name
            is_model_error = any(
                kw in exc_name for kw in ("NotFoundError", "BadRequestError", "InvalidRequest")
            )

            choices = [questionary.Choice("Retry", value="retry")]
            if is_model_error:
                choices.append(questionary.Choice("Change model", value="change_model"))
            if provider.requires_key and is_auth_error:
                choices.append(questionary.Choice("Re-enter API key", value="rekey"))
            choices += [
                questionary.Choice("Skip test and continue setup", value="skip"),
                questionary.Choice("Abort setup", value="abort"),
            ]

            action = questionary.select(
                "How would you like to proceed?",
                choices=choices,
            ).ask()

            if action is None or action == "abort":
                raise SystemExit(0)
            if action == "skip":
                console.print(
                    "  [dim]Test skipped — run [bold]pyra setup[/bold] again if chat doesn't work.[/dim]"
                )
                return model
            if action == "change_model":
                model = _choose_model(provider)
            elif action == "rekey":
                _collect_api_key(provider)
            # loop → retry (with possibly new model or key)