#!/usr/bin/env python3
"""
Patches the TrueNAS webui Angular bundle to show S3 and B2 credentials
in the TrueCloud Backup task form, instead of Storj only.

Angular's Ivy compiler inlines TypeScript string enum values as literals in
the compiled bundle, so the template binding:

    [filterByProviders]="[CloudSyncProviderName.Storj]"

appears verbatim in the minified JS as:

    "filterByProviders",["STORJ_IX"]

We replace that array to include S3 and B2. The file is backed up before
modification so uninstall.sh can restore it.

Safe to run multiple times — a marker string detects an already-patched file.
Exits 0 in all cases (warnings are printed to stdout and logged by apply.sh).
"""

import os
import re
import shutil
import sys

WEBUI_CANDIDATES = [
    "/usr/share/truenas/webui",
    "/usr/share/truenas-ui",
    "/var/www/truenas",
]

# Angular's Ivy template compiler serialises the Storj-only filter as this
# exact substring in every production build we've observed.
FIND = re.compile(r'("filterByProviders",)\["STORJ_IX"\]')
REPLACE = r'\1["STORJ_IX","S3","B2"]'

# A patched file contains both "S3" and "B2" next to "STORJ_IX" in this form.
# This string is specific enough not to appear elsewhere in the bundle.
MARKER = '"STORJ_IX","S3","B2"'


def find_webui():
    for d in WEBUI_CANDIDATES:
        if os.path.isdir(d):
            return d
    return None


def find_bundle(webui):
    """
    Walk the webui directory looking for the JS file that contains the
    filterByProviders binding. Returns (path, content) or (None, None).
    Only .js files are read; binary files and permission errors are skipped.
    """
    matches = []
    for root, _dirs, names in os.walk(webui):
        for name in sorted(names):          # deterministic order
            if not name.endswith(".js"):
                continue
            path = os.path.join(root, name)
            try:
                with open(path, encoding="utf-8", errors="replace") as fh:
                    content = fh.read()
                if FIND.search(content):
                    matches.append((path, content))
            except (UnicodeDecodeError, PermissionError, OSError):
                continue

    if not matches:
        return None, None

    if len(matches) > 1:
        # Unexpected — log all matches so the operator can investigate.
        print(
            f"[truecloud-patch] WARNING: filterByProviders pattern found in "
            f"{len(matches)} files; patching only the first."
        )
        for p, _ in matches:
            print(f"[truecloud-patch]   {p}")

    return matches[0]


def main():
    webui = find_webui()
    if not webui:
        print(
            "[truecloud-patch] WARNING: webui directory not found; skipping UI patch.\n"
            "[truecloud-patch] Searched: " + ", ".join(WEBUI_CANDIDATES)
        )
        return

    path, content = find_bundle(webui)
    if path is None:
        print(
            "[truecloud-patch] WARNING: filterByProviders pattern not found in any JS bundle.\n"
            "[truecloud-patch] The TrueNAS webui may have been restructured in this version.\n"
            "[truecloud-patch] File an issue at https://github.com/sudolulo/truenas-truecloud-patch\n"
            f"[truecloud-patch] TrueNAS version info: {_tnversion()}"
        )
        return

    if MARKER in content:
        print(f"[truecloud-patch] UI already patched: {path}")
        return

    backup = path + ".pre-truecloud-patch"
    if not os.path.exists(backup):
        shutil.copy2(path, backup)

    patched, count = FIND.subn(REPLACE, content)

    try:
        with open(path, "w", encoding="utf-8") as fh:
            fh.write(patched)
    except OSError as exc:
        print(f"[truecloud-patch] ERROR: Could not write {path}: {exc}")
        return

    print(f"[truecloud-patch] UI bundle patched ({count} replacement(s)): {path}")


def _tnversion():
    try:
        with open("/etc/version") as fh:
            return fh.read().strip()
    except OSError:
        return "unknown"


if __name__ == "__main__":
    main()