from __future__ import annotations

from dataclasses import dataclass
from dataclasses import replace
import json
import os
from pathlib import Path
import subprocess
from urllib.parse import urlparse

from .adapters import adapter_for
from .config import AppConfig, default_config
from .plan import BrowsePlan, plan_url


@dataclass(frozen=True)
class BrowserLaunchSpec:
    runtime_path: str
    profile_path: str
    user_js_path: str
    command: tuple[str, ...]
    prefs: tuple[str, ...]


@dataclass(frozen=True)
class OpenPlan:
    browse_plan: BrowsePlan
    status: str
    dry_run: bool
    consent_granted: bool
    profile_path: str
    proxy: str
    setup_steps: tuple[str, ...]
    message: str
    launch_spec: BrowserLaunchSpec | None = None
    transport_setup_status: str = "-"
    transport_setup_message: str = "-"


def prepare_open(
    raw_url: str,
    *,
    consent: bool = False,
    dry_run: bool = True,
    config: AppConfig | None = None,
    platform: str | None = None,
) -> OpenPlan:
    config = config or default_config()
    browse_plan = plan_url(raw_url, config=config, platform=platform)
    profile_path = config.profile_path(browse_plan.route.profile)
    proxy = _proxy_for(browse_plan)
    launch_spec = _launch_spec_for(browse_plan, config=config, profile_path=profile_path)

    if browse_plan.action.startswith("blocked"):
        return OpenPlan(
            browse_plan=browse_plan,
            status="blocked",
            dry_run=dry_run,
            consent_granted=consent,
            profile_path=profile_path,
            proxy=proxy,
            setup_steps=(),
            message=browse_plan.action,
            launch_spec=launch_spec,
        )

    if browse_plan.requires_consent:
        setup_steps = _setup_steps(browse_plan)
        if not consent:
            return OpenPlan(
                browse_plan=browse_plan,
                status="consent-required",
                dry_run=dry_run,
                consent_granted=False,
                profile_path=profile_path,
                proxy=proxy,
                setup_steps=setup_steps,
                message=browse_plan.prompt,
                launch_spec=launch_spec,
            )
        return OpenPlan(
            browse_plan=browse_plan,
            status="setup-approved",
            dry_run=dry_run,
            consent_granted=True,
            profile_path=profile_path,
            proxy=proxy,
            setup_steps=setup_steps,
            message="first-use setup approved; browser launch waits for transport readiness",
            launch_spec=launch_spec,
        )

    return OpenPlan(
        browse_plan=browse_plan,
        status="ready",
        dry_run=dry_run,
        consent_granted=consent,
        profile_path=profile_path,
        proxy=proxy,
        setup_steps=(),
        message="ready to open with isolated profile",
        launch_spec=launch_spec,
    )


def execute_open(open_plan: OpenPlan, *, root: Path | None = None) -> OpenPlan:
    root = root or Path.cwd()
    spec = open_plan.launch_spec
    if spec is None:
        return replace(
            open_plan,
            dry_run=False,
            status="launch-unsupported",
            message=f"no browser launch path for {open_plan.browse_plan.route.transport}",
        )
    if open_plan.status != "ready":
        return replace(
            open_plan,
            dry_run=False,
            message=f"not launched: {open_plan.message}",
        )

    runtime_path = _path_from(root, spec.runtime_path)
    if not runtime_path.exists():
        return replace(
            open_plan,
            dry_run=False,
            status="runtime-missing",
            message=f"browser runtime not found: {spec.runtime_path}",
        )

    _write_profile(root, spec)
    subprocess.Popen(spec.command, cwd=str(root))  # noqa: S603
    return replace(open_plan, dry_run=False, status="launched", message="launched bundled browser")


def _proxy_for(browse_plan: BrowsePlan) -> str:
    if browse_plan.route.transport in {"tor", "i2p"} and browse_plan.status:
        return browse_plan.status.endpoint
    return "-"


def _setup_steps(browse_plan: BrowsePlan) -> tuple[str, ...]:
    if not browse_plan.status:
        return ()
    adapter = adapter_for(browse_plan.route.transport)
    if not adapter:
        return ()

    steps: list[str] = []
    platform = browse_plan.platform_capability.platform
    if platform == "android" and not browse_plan.status.installed:
        steps.append(f"install or enable Android {browse_plan.route.transport} provider")
        steps.extend(adapter.setup_steps(installed=True, platform=platform))
        return tuple(steps)
    if platform == "ios" and not browse_plan.status.installed:
        if browse_plan.route.transport == "tor":
            steps.append("enable bundled iOS Arti Tor runtime")
        else:
            steps.append(f"enable foreground iOS {browse_plan.route.transport} session")
        steps.extend(adapter.setup_steps(installed=True, platform=platform))
        return tuple(steps)
    steps.extend(adapter.setup_steps(installed=browse_plan.status.installed, platform=platform))
    return tuple(steps)


def _launch_spec_for(
    browse_plan: BrowsePlan,
    *,
    config: AppConfig,
    profile_path: str,
) -> BrowserLaunchSpec | None:
    if browse_plan.route.transport not in {"clearnet", "tor", "i2p"}:
        return None
    runtime_path = _runtime_path(config)
    user_js_path = str(Path(profile_path) / "user.js")
    command = (runtime_path, "-no-remote", "-profile", profile_path, browse_plan.route.normalized)
    prefs = _prefs_for(browse_plan)
    return BrowserLaunchSpec(
        runtime_path=runtime_path,
        profile_path=profile_path,
        user_js_path=user_js_path,
        command=command,
        prefs=prefs,
    )


def _runtime_path(config: AppConfig) -> str:
    if config.runtime_path:
        return config.runtime_path
    env_path = os.environ.get("AMPB_BROWSER_BIN")
    if env_path:
        return env_path
    build_root = Path(os.environ.get("AMPB_BROWSER_BUILD_ROOT", "/tmp/ampb-browser-build"))
    for candidate in _runtime_candidates(build_root):
        if candidate.exists():
            return str(candidate)
    return str(_runtime_candidates(build_root)[0])


def _runtime_candidates(build_root: Path) -> tuple[Path, ...]:
    return (
        build_root / "obj/gecko-desktop-source/dist/Nightly.app/Contents/MacOS/firefox",
        build_root / "obj/gecko-desktop-source/dist/bin/firefox",
        build_root / "obj/gecko-desktop-artifact/dist/Nightly.app/Contents/MacOS/firefox",
        build_root / "obj/gecko-desktop-artifact/dist/bin/firefox",
    )


def _prefs_for(browse_plan: BrowsePlan) -> tuple[str, ...]:
    prefs: list[tuple[str, str | int | bool]] = [
        ("browser.shell.checkDefaultBrowser", False),
        ("datareporting.policy.dataSubmissionEnabled", False),
        ("toolkit.telemetry.enabled", False),
        ("network.dns.disablePrefetch", True),
        ("network.predictor.enabled", False),
    ]

    transport = browse_plan.route.transport
    if transport == "tor" and browse_plan.status:
        host, port = _endpoint_host_port(browse_plan.status.endpoint)
        prefs.extend(
            [
                ("network.proxy.type", 1),
                ("network.proxy.socks", host),
                ("network.proxy.socks_port", port),
                ("network.proxy.socks_version", 5),
                ("network.proxy.socks_remote_dns", True),
                ("network.proxy.no_proxies_on", ""),
            ]
        )
    elif transport == "i2p" and browse_plan.status:
        host, port = _endpoint_host_port(browse_plan.status.endpoint)
        prefs.extend(
            [
                ("network.proxy.type", 1),
                ("network.proxy.http", host),
                ("network.proxy.http_port", port),
                ("network.proxy.ssl", host),
                ("network.proxy.ssl_port", port),
                ("network.proxy.no_proxies_on", ""),
            ]
        )
    else:
        prefs.append(("network.proxy.type", 0))

    return tuple(_format_pref(name, value) for name, value in prefs)


def _endpoint_host_port(endpoint: str) -> tuple[str, int]:
    parsed = urlparse(endpoint)
    return parsed.hostname or "127.0.0.1", parsed.port or 0


def _format_pref(name: str, value: str | int | bool) -> str:
    if isinstance(value, bool):
        literal = "true" if value else "false"
    elif isinstance(value, int):
        literal = str(value)
    else:
        literal = json.dumps(value)
    return f"user_pref({json.dumps(name)}, {literal});"


def _write_profile(root: Path, spec: BrowserLaunchSpec) -> None:
    profile_path = _path_from(root, spec.profile_path)
    profile_path.mkdir(parents=True, exist_ok=True)
    user_js_path = _path_from(root, spec.user_js_path)
    text = "// Managed by AMPB. Local browser profile policy.\n" + "\n".join(spec.prefs) + "\n"
    user_js_path.write_text(text, encoding="utf-8")


def _path_from(root: Path, value: str) -> Path:
    path = Path(value)
    if path.is_absolute():
        return path
    return root / path