#!/usr/bin/env python3
"""Build helpers shared by Mark VIII deploy scripts.

stamp_version() stamps release metadata into BUILD COPIES ONLY: callers
always pass a staging/build directory, never the source tree, so the repo
stays clean while every deployed artifact reports the same VERSION.
"""

import json
import os
import re
import sys

VERSION_RE = re.compile(r'^[0-9][A-Za-z0-9._-]{0,31}$')
SERVER_VERSION_LINE = "SERVER_VERSION = '%s'\n"


def _stamp_manifest(path, version):
    try:
        with open(path, encoding='utf-8') as f:
            data = json.load(f)
    except (OSError, ValueError):
        return False
    if not isinstance(data, dict):
        return False
    data['version'] = version
    with open(path, 'w', encoding='ascii') as f:
        json.dump(data, f, indent=2)
        f.write('\n')
    return True


def _stamp_payload_sh(path, version):
    try:
        with open(path, encoding='utf-8') as f:
            lines = f.readlines()
    except OSError:
        return False
    out = []
    replaced = False
    for line in lines:
        m = None if replaced \
            else re.match(r'^(\s*#\s*[Vv]ersion:).*$', line)
        if m:
            out.append(m.group(1) + ' ' + version + '\n')
            replaced = True
        else:
            out.append(line)
    if not replaced:
        insert = 1 if lines and lines[0].startswith('#!') else 0
        out.insert(insert, '# Version: %s\n' % version)
    with open(path, 'w', encoding='utf-8') as f:
        f.writelines(out)
    return True


def _server_insert_index(lines):
    """Index just past any shebang/comments/blanks and module docstring."""
    i = 0
    n = len(lines)
    if i < n and lines[i].startswith('#!'):
        i += 1
    while i < n and (lines[i].strip().startswith('#')
                     or not lines[i].strip()):
        i += 1
    if i < n:
        stripped = lines[i].lstrip()
        quote = stripped[:3]
        if quote in ('"""', "'''"):
            closed_here = quote in stripped[3:]
            i += 1
            if not closed_here:
                while i < n and quote not in lines[i]:
                    i += 1
                i += 1
    return min(i, len(lines))


def _stamp_server_py(path, version):
    try:
        with open(path, encoding='utf-8') as f:
            lines = f.readlines()
    except OSError:
        return False
    lines = [l for l in lines if not l.startswith('SERVER_VERSION')]
    idx = _server_insert_index(lines)
    lines.insert(idx, SERVER_VERSION_LINE % version)
    with open(path, 'w', encoding='utf-8') as f:
        f.writelines(lines)
    return True


def stamp_version(build_dir, version):
    """Stamp <version> into build copies found under build_dir.

    Updates every ``_hak5_manifest.json`` (version field), ``payload.sh``
    (header Version line) and ``server.py`` (injected SERVER_VERSION
    constant near the top). Idempotent: re-running never duplicates the
    injected constant or header. Returns the list of stamped paths."""
    if not VERSION_RE.match(str(version)):
        raise ValueError('invalid version string: %r' % (version,))
    stamped = []
    for root, dirs, files in os.walk(build_dir):
        for fname in ('_hak5_manifest.json', 'payload.sh', 'server.py'):
            if fname in files:
                path = os.path.join(root, fname)
                if fname == '_hak5_manifest.json':
                    ok = _stamp_manifest(path, version)
                elif fname == 'payload.sh':
                    ok = _stamp_payload_sh(path, version)
                else:
                    ok = _stamp_server_py(path, version)
                if ok:
                    stamped.append(path)
    return sorted(stamped)


if __name__ == '__main__':
    if len(sys.argv) != 3:
        print('usage: build_common.py <build_dir> <version>',
              file=sys.stderr)
        sys.exit(2)
    for path in stamp_version(sys.argv[1], sys.argv[2]):
        print('stamped: %s' % path)