import os
import re
from services.runner import run_cmd


def detect_pkg_manager() -> str | None:
    if os.path.exists("/usr/bin/apt"):
        return "apt"
    if os.path.exists("/usr/bin/dnf"):
        return "dnf"
    if os.path.exists("/usr/bin/yum"):
        return "yum"
    if os.path.exists("/usr/bin/pacman"):
        return "pacman"
    return None


async def list_updates() -> tuple[str, list[str]]:
    pm = detect_pkg_manager()
    if not pm:
        return "⚠️ Updates", ["No supported package manager found"]

    if pm == "apt":
        await run_cmd(["sudo", "apt", "update"], timeout=300)
        rc, out = await run_cmd(["apt", "list", "--upgradable"], timeout=120)
        if rc != 0:
            return "❌ Updates (apt)", [f"apt list failed: {out}"]

        lines = []
        for line in out.splitlines():
            if not line or line.startswith("Listing..."):
                continue
            if "upgradable from:" not in line:
                continue
            # Format: name/repo new_ver arch [upgradable from: old]
            m = re.match(r"^(\S+)\s+(\S+)\s", line)
            if not m:
                continue
            name_repo, new_ver = m.group(1), m.group(2)
            name = name_repo.split("/", 1)[0] if "/" in name_repo else name_repo

            old_ver = None
            m_old = re.search(r"upgradable from:\s*([^\]]+)", line)
            if m_old:
                old_ver = m_old.group(1).strip()
            if old_ver:
                lines.append(f"{name}: {old_ver} -> {new_ver}")
            else:
                lines.append(f"{name}: -> {new_ver}")

        if not lines:
            lines = ["No updates"]
        return "📦 Updates (apt)", lines

    if pm == "dnf":
        rc, out = await run_cmd(["sudo", "dnf", "check-update"], timeout=300)
        if rc in (0, 100):
            lines = out.splitlines() or ["No updates"]
            return "📦 Updates (dnf)", lines
        return "❌ Updates (dnf)", [f"dnf check-update failed: {out}"]

    if pm == "yum":
        rc, out = await run_cmd(["sudo", "yum", "check-update"], timeout=300)
        if rc in (0, 100):
            lines = out.splitlines() or ["No updates"]
            return "📦 Updates (yum)", lines
        return "❌ Updates (yum)", [f"yum check-update failed: {out}"]

    if pm == "pacman":
        rc, out = await run_cmd(["pacman", "-Qu"], timeout=120)
        if rc == 0:
            lines = out.splitlines() or ["No updates"]
            return "📦 Updates (pacman)", lines
        return "❌ Updates (pacman)", [f"pacman -Qu failed: {out}"]

    return "⚠️ Updates", ["Unsupported package manager"]


async def apply_updates() -> str:
    pm = detect_pkg_manager()
    if not pm:
        return "⚠️ No supported package manager found"

    if pm == "apt":
        await run_cmd(["sudo", "apt", "update"], timeout=300)
        rc, out = await run_cmd(["sudo", "apt-get", "-y", "upgrade"], timeout=1800)
        return f"⬆️ Upgrade (apt)\n```{out}```" if rc == 0 else f"❌ apt upgrade failed\n```{out}```"

    if pm == "dnf":
        rc, out = await run_cmd(["sudo", "dnf", "-y", "upgrade"], timeout=1800)
        return f"⬆️ Upgrade (dnf)\n```{out}```" if rc == 0 else f"❌ dnf upgrade failed\n```{out}```"

    if pm == "yum":
        rc, out = await run_cmd(["sudo", "yum", "-y", "update"], timeout=1800)
        return f"⬆️ Upgrade (yum)\n```{out}```" if rc == 0 else f"❌ yum update failed\n```{out}```"

    if pm == "pacman":
        rc, out = await run_cmd(["sudo", "pacman", "-Syu", "--noconfirm"], timeout=1800)
        return f"⬆️ Upgrade (pacman)\n```{out}```" if rc == 0 else f"❌ pacman -Syu failed\n```{out}```"

    return "⚠️ Unsupported package manager"