#!/usr/bin/env python3
"""
install_dependencies.py
Installs all requirements for compress_folder.py:
  - Checks the Python version (3.10+)
  - Detects the OS and installs 7-Zip via the appropriate method
  - Verifies the installation when done
"""

import os
import sys
import shutil
import subprocess
import platform


# ── Terminal colors (no third-party deps needed here either) ─────────────────

IS_TTY = sys.stdout.isatty()

def _c(code, text):
    return f"\033[{code}m{text}\033[0m" if IS_TTY else text

def green(t):  return _c("32", t)
def yellow(t): return _c("33", t)
def cyan(t):   return _c("36", t)
def bold(t):   return _c("1",  t)
def dim(t):    return _c("2",  t)
def red(t):    return _c("31", t)


# ── Helpers ───────────────────────────────────────────────────────────────────

def header(text):
    print(f"\n{bold('── ' + text + ' ' + '─' * max(0, 54 - len(text)))}")

def ok(text):    print(f"  {green('✔')}  {text}")
def info(text):  print(f"  {cyan('ℹ')}  {text}")
def warn(text):  print(f"  {yellow('⚠')}  {text}")
def fail(text):  print(f"  {red('✘')}  {text}")

def run(cmd, check=True, capture=False):
    """Run a shell command, print it first, and return the CompletedProcess."""
    print(f"\n  {dim('$')} {dim(' '.join(cmd))}")
    return subprocess.run(
        cmd,
        check=check,
        capture_output=capture,
        text=True,
    )


# ── Step 1: Python version ────────────────────────────────────────────────────

def check_python():
    header("Checking Python version")
    major, minor = sys.version_info[:2]
    ver = f"{major}.{minor}.{sys.version_info.micro}"
    if (major, minor) >= (3, 10):
        ok(f"Python {ver}  — requirement satisfied (3.10+)")
        return True
    else:
        fail(f"Python {ver} is too old. compress_folder.py requires Python 3.10 or higher.")
        info("Download the latest Python from https://www.python.org/downloads/")
        return False


# ── Step 2: Detect OS and pick install strategy ───────────────────────────────

def detect_os() -> dict:
    """Return a dict describing the OS and the best install method."""
    system = platform.system()

    if system == "Windows":
        return {"os": "windows"}

    if system == "Darwin":
        brew   = shutil.which("brew")
        port   = shutil.which("port")
        method = "homebrew" if brew else ("macports" if port else "manual")
        return {"os": "macos", "method": method, "brew": brew, "port": port}

    if system == "Linux":
        # Identify distro family
        for mgr, cmd in (
            ("apt",  ["apt", "--version"]),
            ("dnf",  ["dnf", "--version"]),
            ("yum",  ["yum", "--version"]),
            ("pacman", ["pacman", "--version"]),
            ("zypper", ["zypper", "--version"]),
        ):
            if shutil.which(mgr):
                return {"os": "linux", "manager": mgr}
        return {"os": "linux", "manager": None}

    return {"os": "unknown"}


# ── Step 3: Install 7-Zip ─────────────────────────────────────────────────────

def already_installed() -> str | None:
    """Return the path to 7-Zip if it is already on PATH."""
    for name in ("7z", "7za", "7zz"):
        path = shutil.which(name)
        if path:
            return path
    if sys.platform == "win32":
        for p in (
            r"C:\Program Files\7-Zip\7z.exe",
            r"C:\Program Files (x86)\7-Zip\7z.exe",
        ):
            if os.path.isfile(p):
                return p
    return None


def get_7zip_version(path: str) -> str:
    """Return the version string reported by 7-Zip."""
    try:
        result = subprocess.run(
            [path, "i"], capture_output=True, text=True, check=False
        )
        for line in (result.stdout + result.stderr).splitlines():
            if "7-Zip" in line:
                return line.strip()
    except Exception:
        pass
    return "(version unknown)"


def install_linux(manager: str) -> bool:
    install_cmds = {
        "apt":    ["sudo", "apt", "install", "-y", "p7zip-full"],
        "dnf":    ["sudo", "dnf", "install", "-y", "p7zip", "p7zip-plugins"],
        "yum":    ["sudo", "yum", "install", "-y", "p7zip", "p7zip-plugins"],
        "pacman": ["sudo", "pacman", "-S", "--noconfirm", "p7zip"],
        "zypper": ["sudo", "zypper", "install", "-y", "p7zip"],
    }
    cmd = install_cmds.get(manager)
    if not cmd:
        return False
    try:
        run(cmd)
        return True
    except subprocess.CalledProcessError:
        return False


def install_macos(method: str, brew: str | None, port: str | None) -> bool:
    if method == "homebrew":
        try:
            run([brew, "install", "p7zip"])
            return True
        except subprocess.CalledProcessError:
            return False
    if method == "macports":
        try:
            run(["sudo", port, "install", "p7zip"])
            return True
        except subprocess.CalledProcessError:
            return False
    return False


def install_windows() -> bool:
    """Try winget first, then chocolatey, then fall back to manual."""
    if shutil.which("winget"):
        try:
            run(["winget", "install", "--id", "7zip.7zip", "-e", "--silent"])
            return True
        except subprocess.CalledProcessError:
            pass

    if shutil.which("choco"):
        try:
            run(["choco", "install", "7zip", "-y"])
            return True
        except subprocess.CalledProcessError:
            pass

    return False


def install_7zip(os_info: dict) -> bool:
    header("Installing 7-Zip")

    # Already present?
    path = already_installed()
    if path:
        ver = get_7zip_version(path)
        ok(f"7-Zip is already installed:  {dim(path)}")
        ok(f"{dim(ver)}")
        return True

    system = os_info["os"]

    if system == "linux":
        manager = os_info.get("manager")
        if not manager:
            fail("No supported package manager found (apt / dnf / yum / pacman / zypper).")
            info("Install 7-Zip manually: https://www.7-zip.org/download.html")
            return False
        info(f"Using package manager: {bold(manager)}")
        success = install_linux(manager)

    elif system == "macos":
        method = os_info.get("method", "manual")
        if method == "manual":
            fail("Neither Homebrew nor MacPorts was found.")
            info("Install Homebrew first:  https://brew.sh")
            info("Then re-run this script, or install p7zip manually.")
            return False
        info(f"Using: {bold(method)}")
        success = install_macos(method, os_info.get("brew"), os_info.get("port"))

    elif system == "windows":
        info("Trying winget → chocolatey …")
        success = install_windows()
        if not success:
            fail("Automatic install failed.")
            info("Download 7-Zip manually from: https://www.7-zip.org/download.html")
            info("After installing, re-run this script to verify.")
            return False

    else:
        fail(f"Unsupported OS: {platform.system()}")
        info("Install 7-Zip manually: https://www.7-zip.org/download.html")
        return False

    if not success:
        fail("Installation command failed. Check the output above for details.")
        return False

    return True


# ── Step 4: Verify everything ─────────────────────────────────────────────────

def verify():
    header("Verifying installation")

    path = already_installed()
    if path:
        ver = get_7zip_version(path)
        ok(f"7-Zip found:  {dim(path)}")
        ok(f"{dim(ver)}")
        return True
    else:
        fail("7-Zip still not found on PATH after installation.")
        warn("You may need to restart your terminal or add 7-Zip to your PATH manually.")
        if sys.platform == "win32":
            info("Typical Windows location: C:\\Program Files\\7-Zip\\")
            info("Add that directory to your PATH environment variable.")
        return False


# ── Main ──────────────────────────────────────────────────────────────────────

def main():
    print(f"\n{bold('🔧  compress_folder.py — Dependency Installer')}")
    print(f"    Platform: {cyan(platform.system())} {platform.release()}  |  "
          f"Python {sys.version.split()[0]}")

    all_ok = True

    # 1. Python check
    if not check_python():
        all_ok = False

    # 2. Detect OS
    header("Detecting operating system")
    os_info = detect_os()
    system  = os_info["os"]

    if system == "linux":
        mgr = os_info.get("manager", "unknown")
        ok(f"Linux detected  —  package manager: {bold(mgr)}")
    elif system == "macos":
        method = os_info.get("method", "manual")
        ok(f"macOS detected  —  install method: {bold(method)}")
    elif system == "windows":
        ok("Windows detected")
    else:
        warn(f"Unrecognised OS: {platform.system()}")

    # 3. Install 7-Zip
    if not install_7zip(os_info):
        all_ok = False

    # 4. Verify
    verified = verify()
    if not verified:
        all_ok = False

    # 5. Final report
    header("Summary")
    if all_ok and verified:
        print(f"\n  {green('✅  All dependencies satisfied.')}")
        print(f"     You are ready to run:  {bold('python compress_folder.py')}\n")
    else:
        print(f"\n  {yellow('⚠  One or more steps did not complete successfully.')}")
        print( "     Review the output above and resolve any issues before running")
        print(f"     {bold('compress_folder.py')}.\n")
        sys.exit(1)


if __name__ == "__main__":
    main()