#!/usr/bin/env python3
"""
vault_ops.py — write operations for the `vault` CLI.
Clobber-safe by construction: refuse if destination exists, refuse if source missing.
Every op is dry-run unless execute=True. Operates on BOTH /vault and /data + manifest.
"""
import os, re, sys, subprocess
_SELF_DIR = os.path.dirname(os.path.realpath(__file__))
sys.path.insert(0, _SELF_DIR)
import vault_lib as vl

WIKILINK_RE = re.compile(r'(!?\[\[)([^\]#|]+)((?:#[^\]|]+)?(?:\|[^\]]+)?)(\]\])')


def _die(m):
    print("ERROR: " + m, file=sys.stderr); sys.exit(1)


def _sys_root(letter):
    s = vl.walk_structure(vl.VAULT, include_meta=True)["systems"]
    if letter not in s:
        _die(f"unknown system '{letter}'")
    return os.path.join(vl.VAULT, s[letter])


def _find_id_folder(root, code):
    for dp, dns, fns in os.walk(root):
        dns[:] = [d for d in dns if d not in vl.SKIP_DIRS]
        if vl.id_code(os.path.basename(dp)) == code:
            return dp
    return None


def _find_cat_folder(root, catcode):
    for dp, dns, fns in os.walk(root):
        dns[:] = [d for d in dns if d not in vl.SKIP_DIRS]
        if vl.cat_code(os.path.basename(dp)) == catcode:
            return dp
    return None


def _rewrite_links(old_stem, new_stem, execute):
    """Rewrite [[old_stem]] -> [[new_stem]] vault-wide. Returns count."""
    n = 0
    for p in vl.all_notes(vl.VAULT):
        try:
            txt = open(p, encoding="utf-8").read()
        except Exception:
            continue
        def repl(m):
            nonlocal n
            if m.group(2).strip() == old_stem:
                n += 1
                return f"{m.group(1)}{new_stem}{m.group(3)}{m.group(4)}"
            return m.group(0)
        new = WIKILINK_RE.sub(repl, txt)
        if new != txt and execute:
            open(p, "w", encoding="utf-8").write(new)
    return n


def _git_commit(msg, execute):
    if not execute:
        return
    subprocess.run(["git", "-C", vl.VAULT, "add", "-A"], check=False)
    subprocess.run(["git", "-C", vl.VAULT, "commit", "-m", msg], check=False)


def op_create(argv, execute):
    if len(argv) < 2:
        _die('usage: vault create <ID> "<title>"')
    code, title = argv[0], argv[1]
    if not vl.ID_RE.match(code + " x"):
        _die(f"'{code}' is not a valid SYS.AC.ID code")
    root = _sys_root(code[0])
    catcode = code[:code.rindex(".")]
    catfolder = _find_cat_folder(root, catcode)
    if not catfolder:
        _die(f"category {catcode} does not exist — create it first")
    if _find_id_folder(root, code):
        _die(f"CLOBBER: ID {code} already exists")
    leaf = f"{code} {title}"
    vpath = os.path.join(catfolder, leaf)
    vnote = os.path.join(vpath, leaf + ".md")
    drel = os.path.relpath(vpath, vl.VAULT)
    dpath = os.path.join(vl.DATA, drel)
    print(f"CREATE  /vault: {os.path.relpath(vpath, vl.VAULT)}")
    print(f"        folder-note: {leaf}.md")
    print(f"        /data:  {drel}")
    if os.path.exists(dpath):
        _die(f"CLOBBER: /data path already exists: {drel}")
    if execute:
        os.makedirs(vpath)
        with open(vnote, "w", encoding="utf-8") as f:
            f.write(f"# {leaf}\n")
        os.makedirs(dpath)
        _git_commit(f"vault create {code} {title}", execute)
        print("EXECUTED.")
    else:
        print("DRY-RUN — nothing changed. Add --execute.")


def op_move(argv, execute):
    if len(argv) < 2:
        _die("usage: vault move <oldID> <newID>")
    old, new = argv[0], argv[1]
    root = _sys_root(old[0])
    oldf = _find_id_folder(root, old)
    if not oldf:
        _die(f"source ID {old} not found")
    newroot = _sys_root(new[0])
    if _find_id_folder(newroot, new):
        _die(f"CLOBBER: destination ID {new} already exists")
    newcat = new[:new.rindex(".")]
    newcatf = _find_cat_folder(newroot, newcat)
    if not newcatf:
        _die(f"destination category {newcat} does not exist")
    old_base = os.path.basename(oldf)
    title = old_base.split(" ", 1)[1] if " " in old_base else ""
    new_base = f"{new} {title}".strip()
    new_folder = os.path.join(newcatf, new_base)
    old_stem, new_stem = old_base, new_base
    old_drel = os.path.relpath(oldf, vl.VAULT)
    new_drel = os.path.relpath(new_folder, vl.VAULT)
    print(f"MOVE  {old_base}  ->  {new_base}")
    print(f"      /vault: {old_drel}  ->  {new_drel}")
    print(f"      /data:  {old_drel}  ->  {new_drel}")
    print(f"      backlink rewrite: [[{old_stem}]] -> [[{new_stem}]]")
    n = _rewrite_links(old_stem, new_stem, execute)
    print(f"      ({n} backlink(s))")
    if execute:
        # rename folder-note first, then folder
        oldnote = os.path.join(oldf, old_base + ".md")
        if os.path.exists(oldnote):
            os.rename(oldnote, os.path.join(oldf, new_base + ".md"))
        os.rename(oldf, new_folder)
        olddata = os.path.join(vl.DATA, old_drel)
        if os.path.isdir(olddata):
            os.makedirs(os.path.dirname(os.path.join(vl.DATA, new_drel)), exist_ok=True)
            os.rename(olddata, os.path.join(vl.DATA, new_drel))
        _regen_manifest(execute)
        _git_commit(f"vault move {old} -> {new}", execute)
        print("EXECUTED.")
    else:
        print("DRY-RUN — nothing changed. Add --execute.")


def op_rename(argv, execute):
    if len(argv) < 2:
        _die('usage: vault rename <ID> "<new title>"')
    code, title = argv[0], argv[1]
    root = _sys_root(code[0])
    f = _find_id_folder(root, code)
    if not f:
        _die(f"ID {code} not found")
    old_base = os.path.basename(f)
    new_base = f"{code} {title}"
    if old_base == new_base:
        _die("new title identical to current")
    parent = os.path.dirname(f)
    if os.path.exists(os.path.join(parent, new_base)):
        _die(f"CLOBBER: {new_base} already exists")
    print(f"RENAME  {old_base}  ->  {new_base}")
    n = _rewrite_links(old_base, new_base, execute)
    print(f"        ({n} backlink(s))")
    if execute:
        oldnote = os.path.join(f, old_base + ".md")
        if os.path.exists(oldnote):
            os.rename(oldnote, os.path.join(f, new_base + ".md"))
        newf = os.path.join(parent, new_base)
        os.rename(f, newf)
        drel_old = os.path.relpath(f, vl.VAULT)
        drel_new = os.path.relpath(newf, vl.VAULT)
        od = os.path.join(vl.DATA, drel_old)
        if os.path.isdir(od):
            os.rename(od, os.path.join(vl.DATA, drel_new))
        _regen_manifest(execute)
        _git_commit(f"vault rename {code}", execute)
        print("EXECUTED.")
    else:
        print("DRY-RUN — nothing changed. Add --execute.")


def op_sync_data(argv, execute):
    """Create any /data skeleton dir that a /vault ID/cat/area lacks. Never deletes."""
    v = vl.walk_structure(vl.VAULT, include_meta=False)
    made = []
    for level in ("areas", "cats", "ids"):
        for code, rel in sorted(v[level].items()):
            dpath = os.path.join(vl.DATA, rel)
            if not os.path.isdir(dpath):
                made.append(rel)
                if execute:
                    os.makedirs(dpath, exist_ok=True)
    print(f"sync-data: {len(made)} /data dir(s) {'created' if execute else 'to create'}")
    for m in made[:40]:
        print("  + " + m)
    if len(made) > 40:
        print(f"  ... and {len(made)-40} more")
    if execute:
        _git_commit(f"vault sync-data ({len(made)} /data dir(s))", execute)
        print("EXECUTED.")
    else:
        print("DRY-RUN — nothing changed. Add --execute.")


def _regen_manifest(execute):
    if execute:
        subprocess.run([sys.executable, os.path.join(_SELF_DIR, "vault-topology.py"), "--execute"], check=False)


def op_manifest(argv, execute):
    subprocess.run([sys.executable, os.path.join(_SELF_DIR, "vault-topology.py")] +
                   (["--execute"] if execute else []), check=False)


def run(cmd, argv, execute):
    {
        "create": op_create,
        "move": op_move,
        "rename": op_rename,
        "sync-data": op_sync_data,
        "manifest": op_manifest,
    }[cmd](argv, execute)