import sys
import io
import pycurl
from bs4 import BeautifulSoup
from pathlib import Path
import os
import notify2
from time import sleep
import subprocess
import json

state_dir = Path(
    os.environ.get("XDG_STATE_HOME", Path.home() / ".local" / "state")
) / "nixpkgs-notify"
state_dir.mkdir(parents=True, exist_ok=True)

trackedPRPath = state_dir / "tracked.txt"
trackedPRFile = Path(trackedPRPath)

config_dir = Path(
    os.environ.get("XDG_CONFIG_HOME", Path.home() / ".config")
) / "nixpkgs-notify"

configPath = config_dir / "config.json"
configFile = Path(configPath)

# parse config file
DEFAULT_CONFIG = {
    "configTime": 3600,
    "configFetchTime": 1,
    "localNotify": True,
    "matrix": {
        "enable": False,
        "room": "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
        "ping": False,
        "userPing": "@someone",
        "userPingServer": "matrix.org"
    }
}
def getPRTitle(PRnumber):
    buf = io.BytesIO()
    with pycurl.Curl() as c:
        c.setopt(c.URL, "https://api.github.com/repos/NixOS/nixpkgs/pulls/" + str(PRnumber))
        c.setopt(c.USERAGENT, "pycurl")
        c.setopt(c.WRITEDATA, buf)
        c.perform()
    return json.loads(buf.getvalue())["title"]

def load_config():
    config_dir.mkdir(parents=True, exist_ok=True)

    if not configFile.exists():
        with configFile.open("w") as f:
            json.dump(DEFAULT_CONFIG, f, indent=2)
        return DEFAULT_CONFIG

    try:
        with configFile.open("r") as f:
            return json.load(f)
    except json.JSONDecodeError:
        print("Config file is broken. Using default config.")
        return DEFAULT_CONFIG

def addTracker(PRnumber):
    result = fetchStatus(PRnumber)
    if result == "accepted":
        print("PR " + str(PRnumber) + " was already merged into nixos-unstable.")
    elif result == "not_found":
        print("PR " + str(PRnumber) + " not found.")
    elif result == "unknown":
        print("PR " + str(PRnumber) + " returned unknown status.")
    elif result == "pending":
        with trackedPRFile.open("a") as f:
            f.write(f"{PRnumber}\n")
    print("Added tracked PR " + str(PRnumber) + " " + getPRTitle(PRnumber))

def removeTracker(PRnumber):
    if not trackedPRFile.exists():
        return

    with trackedPRFile.open("r") as f:
        lines = f.readlines()

    with trackedPRFile.open("w") as f:
        for line in lines:
            if line.strip() != str(PRnumber):
                f.write(line)

    print("Removed tracked PR " + str(PRnumber) + " " + getPRTitle(PRnumber))

def localNotify(PRnumber):
    notify2.init("nixpkgs-tracker-notify")

    notification = notify2.Notification(
        "nixpkgs PR merged",
        "PR #" + str(PRnumber) + " " +  getPRTitle(PRnumber) + "\n" 
        "is now available in nixos-unstable.\n"
        f"https://nixpk.gs/pr-tracker.html?pr={PRnumber}",
    )

    notification.show()

def matrix_check_whoami():
    try:
        result = subprocess.run(
            ["matrix-commander-rs", "--whoami"],
            capture_output=True,
            text=True,
            check=True
        )

        output = result.stdout.strip()

        if output.startswith("@"):
            return output  # OK, proceed
        else:
            print(f"Error: invalid identity returned: {output}")
            return None

    except FileNotFoundError:
        print("Error: matrix-commander-rs not found in PATH.")
        return None

    except subprocess.CalledProcessError as e:
        print(f"Error: command failed with exit code {e.returncode}")
        print(e.stderr.strip())
        return None

def matrixNotify(PRnumber):
    if matrix_check_whoami():
        command = "matrix-commander-rs -m \"PR #" + str(PRnumber) + "  " + getPRTitle(PRnumber) + " is now available in nixos-unstable.\nhttps://nixpk.gs/pr-tracker.html?pr=" + str(PRnumber)
        if matrixPing:
            command += '\n<a href=\\"https://matrix.to/#/' + matrixUserToPing + ':' + matrixUserServer + '\\">' + matrixUserToPing + '</a>\" --html'
        else:
            command += "\""
        command += " -r \"" + matrixRoom + "\""
        subprocess.run(
            command,
            shell=True,
            capture_output=True,
            text=True
        )
def fetchStatus(PRnumber):
    buf = io.BytesIO()

    c = pycurl.Curl()
    c.setopt(c.URL, f"https://nixpk.gs/pr-tracker.html?pr={PRnumber}")
    c.setopt(c.WRITEDATA, buf)
    c.perform()
    c.close()

    soup = BeautifulSoup(buf.getvalue(), "html.parser")

    # Check if the PR does not exist
    no_pr_msg = soup.find(
        string=lambda s: s and f"No such nixpkgs PR #{PRnumber}" in s
    )
    if no_pr_msg:
        return "not_found"

    # Check nixos-unstable status
    for a in soup.find_all("a"):
        if a.get_text(strip=True) == "nixos-unstable":
            span = a.find_parent("li").find("span")
            classes = span.get("class", [])

            if "state-accepted" in classes:
                return "accepted"
            elif "state-pending" in classes:
                return "pending"
            elif "state-rejected" in classes:
                return "rejected"
            else:
                return "unknown"

    return "unknown"

def main():
    # fetch config
    cfg = load_config()
    configTime = cfg["configTime"]
    configFetchTime = cfg["configFetchTime"]
    shouldLocalNotify = cfg["localNotify"]
    shouldMatrixNotify = cfg["matrix"]["enable"]
    matrixRoom = cfg["matrix"]["room"]
    matrixPing = cfg["matrix"]["ping"]
    matrixUserToPing = cfg["matrix"]["userPing"]
    matrixUserServer = cfg["matrix"]["userPingServer"]
    
    
    if len(sys.argv) < 2:
        print("Missing command")
        sys.exit(1)
    if sys.argv[1] == "add":
        for PR in sys.argv:
            if PR != sys.argv[0] and PR != sys.argv[1]:
                try:
                    PR = int(PR)
                    addTracker(PR)
                except ValueError:
                    print(f"{PR} is not an int")
                    continue
            sleep(configFetchTime) # avoid spamming requests
    
    
    elif sys.argv[1] == "remove" or sys.argv[1] == "rm":
        for PR in sys.argv:
            if PR != sys.argv[0] and PR != sys.argv[1]:
                try:
                    PR = int(PR)
                    removeTracker(PR)
                except ValueError:
                    print(f"{PR} is not an int")
                    continue
            sleep(configFetchTime) # avoid spamming requests
    
    elif sys.argv[1] == "list" or sys.argv[1] == "ls":
        if not trackedPRFile.exists():
            print("No tracked PRs.")
        else:
            print("Tracked PRs:")
            with trackedPRFile.open("r") as f:
                for line in f:
                    pr = line.strip()
                    if pr:
                        print("  " + str(pr) + "  " + getPRTitle(pr))
    
    elif sys.argv[1] == "listen":
        while True:
            if trackedPRFile.exists():
                with trackedPRFile.open("r") as f:
                    for line in f:
                        PR = int(line.strip())
                        if fetchStatus(PR) == "accepted":
                            if shouldLocalNotify:
                                localNotify(PR)
                            if shouldMatrixNotify:
                                matrixNotify(PR)
                            removeTracker(PR)
                        sleep(configFetchTime) # avoids to send request to quickly to the website
            sleep(configTime)
    
    else:
        print("Unknown argument \"" + sys.argv[1] + "\"\nAccepted arguments are:\n    add\n    remove or rm\n    list or ls\n    listen")