#!/usr/bin/python3
# Copyright (C) 2026 Danilo M. <danix@danix.xyz>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.

"""The LAN map as JSON: one entry per host note in the vault, each carrying
the ~/.ssh/config aliases that point at it, plus one entry per alias that
points at no note, so every alias the rofi menu listed is still here.

    hosts.py           print the list
    hosts.py --check   run the self-check
"""

import json
import os
import sys
from pathlib import Path

VAULT = os.environ.get(
    "HOSTS_DIR", "~/Documents/Obsidian/my KB/Knowledge base/Local Network/services")
SSH_CONFIG = "~/.ssh/config"


def frontmatter(text):
    """The `key: value` lines between the first two `---` lines."""
    # ponytail: flat scalars only, no yaml lib; a list value stays its raw
    # string, which is fine for the fields read here.
    lines = text.splitlines()
    if not lines or lines[0].strip() != "---":
        return {}
    out = {}
    for line in lines[1:]:
        if line.strip() == "---":
            break
        key, sep, value = line.partition(":")
        if sep and key.strip() and not key.startswith(" "):
            out[key.strip()] = value.strip().strip("\"'")
    return out


def ssh_hosts(text):
    """Aliases in an ssh config: {alias, hostname, user, port}."""
    # ponytail: plain "Keyword value" lines only, like blackpearl-sshmenu.sh;
    # Include and Match are not followed, wildcard Host patterns are skipped.
    hosts, cur = [], None
    for line in text.splitlines():
        parts = line.split(None, 1)
        if len(parts) < 2 or parts[0].startswith("#"):
            continue
        key, value = parts[0].lower(), parts[1].strip()
        if key == "host":
            name = value.split()[0]
            cur = None if any(c in name for c in "*?") else {
                "alias": name, "hostname": name, "user": "", "port": ""}
            if cur:
                hosts.append(cur)
        elif cur and key in ("hostname", "user", "port"):
            cur[key] = value
    return hosts


def merge(notes, aliases):
    """notes: [(title, frontmatter)]. Each alias joins the first note whose ip
    or hostname is its HostName, or whose short hostname is the alias."""
    out = []
    for title, fm in notes:
        out.append({
            "name": title,
            "ip": fm.get("ip", ""),
            "port": fm.get("port", ""),
            "url": fm.get("url", ""),
            "hostname": fm.get("hostname", ""),
            "node": fm.get("node", ""),
            "ct_id": fm.get("ct_id", ""),
            "aliases": [],
            "user": "",
        })
    for a in aliases:
        target = a["hostname"]
        host = next((h for h in out if target and target in (h["ip"], h["hostname"])
                     or a["alias"] == h["hostname"].split(".")[0]), None)
        if host:
            host["aliases"].append(a["alias"])
            host["user"] = host["user"] or a["user"]
        else:
            out.append({
                "name": a["alias"], "ip": target, "port": a["port"], "url": "",
                "hostname": target, "node": "", "ct_id": "",
                "aliases": [a["alias"]], "user": a["user"],
            })
    return out


def main():
    notes = [(p.stem, frontmatter(p.read_text(errors="replace")))
             for p in sorted(Path(VAULT).expanduser().glob("*.md"))]
    cfg = Path(SSH_CONFIG).expanduser()
    aliases = ssh_hosts(cfg.read_text(errors="replace")) if cfg.exists() else []
    json.dump(merge(notes, aliases), sys.stdout)


def check():
    fm = frontmatter("---\ntags: [a, b]\nip: 10.0.0.7\nport: 5000\n"
                     "node: HP server\n---\nbody: not this\n")
    assert fm == {"tags": "[a, b]", "ip": "10.0.0.7", "port": "5000",
                  "node": "HP server"}, fm
    assert frontmatter("no frontmatter\n") == {}

    cfg = ssh_hosts("Host *\n  User x\nHost box\n  HostName 10.0.0.7\n"
                    "  User root\nHost web\n  HostName web.example.org\n"
                    "Host lone\n  Port 2222\n")
    assert [h["alias"] for h in cfg] == ["box", "web", "lone"], cfg
    assert cfg[0]["user"] == "root" and cfg[2]["port"] == "2222"

    hosts = merge([("Box", fm), ("Web", {"hostname": "web.example.org"}),
                   ("Media", {"ip": "10.0.0.9", "hostname": "media.example.org"})],
                  cfg + ssh_hosts("Host media\n  HostName 10.0.0.99\n"))
    by = {h["name"]: h for h in hosts}
    assert by["Box"]["aliases"] == ["box"] and by["Box"]["user"] == "root"
    assert by["Web"]["aliases"] == ["web"]
    assert by["Media"]["aliases"] == ["media"], "short hostname match"
    assert by["lone"]["port"] == "2222" and by["lone"]["node"] == ""
    assert len(hosts) == 4
    print("ok")


if __name__ == "__main__":
    check() if "--check" in sys.argv else main()