import os
import subprocess
import getpass
from sys import argv, stdout, stderr
from datetime import datetime, timezone
from . import args_helpers, identity, issue, issue_tracker

help_text = """\
Usage: xpit create [options]
Examples:
    xpit create
    xpit create -u Bob -i secret_bob_alias -r 20260101_120000:20260101_140000 -x
    xpit create -e_ -t "Startup slow" -l performance,startup -d "The window takes 200ms to open."
Options:
    -d, --description <str>
        The post body.
        Defaults to 'Description goes here...'
    -x, --disable-inline-annotations
        Disable the explanatory ; annotations in newly created posts' headers.
    -e, --editor <str>
        Which editor to open the issue in.
        Pass '_' (underscore) to not open an editor.
        If not specified, the editor is chosen in the following order:
            1. $XPIT_EDITOR
            2. $GIT_EDITOR
            3. $EDITOR
            4. $VISUAL
            5.
                windows: "notepad"
                other: "vi"
    -i, --identity <str>
        Label for keypair used for unique identification and signature.
        This is used to uniquely identify a user.
        Keys are stored in '~/.config/xpit/identities/'.
        Defaults to 'default'.
    -l, --labels <str>
        Comma-separated list of labels applicable to this issue.
        Not compatible with --reply-to.
        Empty by default.
    -r, --reply-to <ISSUE_ID>[:LOCAL_ID]
        Reply to an issue or a specific reply within an issue.
    -P, --skip-prompt
        Skip interactive prompts for missing fields (title, description, labels).
        Only applies when using `-e_` (no automatic editor).
    -t, --title <str>
        The issue's title.
        Not compatible with --reply-to.
        Defaults to 'Title'.
    -u, --username <str>
        The username to use for the issue.
        If not specified, uses `getpass.getuser()`.
    -h, --help
        Print this help text.
"""

class Args:
    def __init__(self):
        self.config_dir: str
        self.editor: str
        self.username: str
        self.identity: str = "default"
        self.reply_to: str | None = None
        self.disable_inline_annotations: bool = False

        self.labels: bytes = b""
        self.skip_prompt: bool = False
        self.description: bytes = b"Description goes here..."
        self.title: bytes = b"Title"

    def parse(self) -> bool:
        flag_value_map = {
            "help|h": 0,
            "description|d": 1,
            "disable-inline-annotations|x": 0,
            "editor|e": 1,
            "identity|i": 1,
            "labels|l": 1,
            "reply|r": 1,
            "skip-prompt|P": 0,
            "title|t|": 1,
            "username|u": 1,
        }
        res = args_helpers.parse_generic(flag_value_map, argv, 2)
        _editor: str | None = None
        _username: str | None = getpass.getuser()
        if res is None:
            return False
        if "help" in res:
            stdout.write(help_text)
            return False
        if "description" in res:
            self.description = res["description"][0].encode("utf-8")
        if "disable-inline-annotations" in res:
            self.disable_inline_annotations = True
        if "editor" in res:
            _editor = res["editor"][0]
        if "identity" in res:
            self.identity = res["identity"][0]
        if "labels" in res:
            labels: str = res["labels"][0]
            issue_tracker.load_config()
            for label in labels.split(','):
                if label.encode("utf-8") not in issue_tracker.config[b"allowed_labels"]:
                    stderr.write(
                        f"Label '{label}' not allowed.\nAllowed: "
                        +issue_tracker.config[b"allowed_labels"].decode("utf-8")
                        +'\n')
                    return False
            self.labels = labels.encode("utf-8")
        if "reply" in res:
            self.reply_to = res["reply"][0]
        if "skip-prompt" in res:
            self.skip_prompt = True
        if "title" in res:
            self.title = res["title"][0].encode("utf-8")
        if "username" in res:
            _username = res["username"][0]

        if _username is None:
            stderr.write("No username.")
            return False
        self.username = _username

        if _editor is None:
            _editor = (
                   os.environ.get("XPIT_EDITOR")
                or os.environ.get("GIT_EDITOR")
                or os.environ.get("EDITOR")
                or os.environ.get("VISUAL")
                or None
            )
        if _editor is None:
            if os.name == "nt":
                _editor = "notepad"
            else:
                _editor = "vi"
        self.editor = _editor

        if os.name == "nt":
            appdata = os.getenv("APPDATA")
            if appdata is None:
                stderr.write("Couldn't find $APPDATA directory")
                return False
            self.config_dir = os.path.join(appdata, "xpit")
        else:
            home = os.getenv("HOME")
            if home is None:
                stderr.write("Couldn't find $HOME directory")
                return False
            self.config_dir = os.path.join(home, ".config", "xpit")

        return True
args = Args()

def id_gen() -> str:
    return datetime.now(timezone.utc).strftime(issue_tracker.config[b"id_format"].decode("utf-8"))

def main() -> int:
    if len(argv) < 2:
        stdout.write(help_text)
        return 1

    if not args.parse():
        return 1

    identities_dir = os.path.join(args.config_dir, "identities")
    private_key, public_key = identity.load(identities_dir, args.identity)
    _ = private_key

    issue_tracker.load_config()
    if issue_tracker.dir is None:
        stderr.write("xpit not initialized. Run `xpit init`.\n")
        return 1

    if args.reply_to is None:
        issue_id = id_gen()
    else:
        issue_id = args.reply_to.split(":", 1)[0]
    issue_dir = os.path.join(issue_tracker.dir, issue_id)
    if args.reply_to is None:
        if os.path.exists(issue_dir):
            stderr.write(f"Failed to create issue {issue_id}: Already exists.\n")
            return 1
        os.mkdir(issue_dir)

    issue_tracker_path = os.path.join(issue_dir, "issue.md")
    if args.reply_to is not None:
        if not os.path.isfile(issue_tracker_path):
            stderr.write(f"Issue {issue_id} not found.\n")
            return 1
        with open(issue_tracker_path, "r+b") as f:
            src = f.read()
            info, err = issue.parse(src)
            if err is not None:
                stderr.write(err.msg)
                return 1
            if info.meta[b"status"] != b"open":
                stderr.write(f"Issue {issue_id} already closed.\n")
                return 1

    identity_id = identity.id_from_pubkey(public_key)
    # help_author = b" ; your user-ID"
    # help_status = b" ; open | closed"
    allowed_labels = issue_tracker.config[b"allowed_labels"]
    help_labels = b" ; comma-separated list. Allowed labels are: "+allowed_labels
    # help_id =     b" ; this reply's local ID"
    # help_reply =  b" ; local ID of the post you're replying to"
    if args.disable_inline_annotations:
        help_labels = b""
    if args.editor == "_" and not args.skip_prompt:
        if args.title is None:
            args.title = input("Title: ").encode("utf-8")
        if args.labels is None:
            args.labels = input("Labels (Comma-separated): ").encode("utf-8")
        if args.description is None:
            args.description = input("Description: ").encode("utf-8")
    with open(issue_tracker_path, "ab") as f:
        ini_author = b"author=" + args.username.encode("utf-8") + b'#' + identity_id + b'\n'
        if args.reply_to is None:
            ini_status = b"status=open\n"
            ini_labels = b"labels="+args.labels + help_labels + b'\n'
            ini_add_after_edit = ini_author + ini_status
            ini_add_now = ini_labels
            if args.editor == "_":
                ini_add_now = ini_add_after_edit + ini_add_now
            msg = b"```ini\n"+ini_add_now+b"""```

# """+args.title+b"""

"""+args.description+b"""

"""
        else:
            ini_id = b"id="+id_gen().encode("utf-8")+b'\n'
            reply_to = args.reply_to.split(":", 2)
            ini_reply = b""
            if len(reply_to) == 2:
                ini_reply = b"reply="+reply_to[1].encode("utf-8")+b'\n'
            ini_add_after_edit = ini_author + ini_id
            ini_add_now = ini_reply
            if args.editor == "_":
                ini_add_now = ini_add_after_edit + ini_add_now
            msg = b"---\n```ini\n"+ini_add_now+b"```\n\n"+args.description+b"\n\n"
        f.write(msg)

    if args.editor != "_":
        subprocess.call([args.editor, issue_tracker_path])
        with open(issue_tracker_path, "r+b") as f:
            src = f.read()
            src = issue.clean_after_edit(src, ini_add_after_edit)
            f.seek(0)
            f.write(src)
            f.truncate()
            # TODO check if labels ok. Maybe we want to have some sort of `check` command

    relpath = os.path.relpath(issue_tracker_path, os.getcwd())
    if args.reply_to is None:
        stdout.write(f"Created new issue ./{relpath}\n")
    else:
        stdout.write(f"Replied to {args.reply_to}\n")

    return 0