#!/usr/bin/env python3
"""Apply the two link-fix passes across /vault:
1. fix_map: [[OldTarget]] -> [[NewNote|OldTarget]] (preserves display text)
   Also handles piped/heading variants: [[OldTarget|Display]] -> [[NewNote|Display]]
                                          [[OldTarget#Heading]] -> [[NewNote#Heading]]
2. unlink_targets: [[Target]] -> Target (plain text, drop brackets)
   Also handles piped: [[Target|Display]] -> Display
"""
import os, re, json, sys

VAULT = "/vault"

with open("/tmp/link_fix_map.json") as f:
    FIX_MAP = json.load(f)
with open("/tmp/unlink_targets.json") as f:
    UNLINK = set(json.load(f))

# Full link regex capturing target, optional #heading, optional |display
LINK_RE = re.compile(r'\[\[([^\]|#]+)(#[^\]|]*)?(\|[^\]]*)?\]\]')

def process_text(text):
    changed = False
    def repl(m):
        nonlocal changed
        target = m.group(1)
        heading = m.group(2) or ""
        pipe_display = m.group(3)  # includes leading |
        target_stripped = target.strip()

        if target_stripped in FIX_MAP:
            new_target = FIX_MAP[target_stripped]
            changed = True
            if pipe_display:
                # keep existing custom display text
                return f"[[{new_target}{heading}{pipe_display}]]"
            else:
                # preserve original text as display so prose doesn't change visually
                return f"[[{new_target}{heading}|{target_stripped}]]"

        if target_stripped in UNLINK:
            changed = True
            if pipe_display:
                display = pipe_display[1:]  # strip leading |
                return display
            else:
                return target_stripped

        return m.group(0)  # unchanged

    new_text = LINK_RE.sub(repl, text)
    return new_text, changed

def main():
    execute = "--execute" in sys.argv
    files_changed = 0
    total_fix_applied = 0
    total_unlink_applied = 0

    for dp, _, fns in os.walk(VAULT):
        if ".git" in dp.split(os.sep):
            continue
        for fn in fns:
            if not fn.lower().endswith(".md"):
                continue
            p = os.path.join(dp, fn)
            try:
                with open(p, "r", encoding="utf-8", errors="ignore") as f:
                    text = f.read()
            except Exception:
                continue
            new_text, changed = process_text(text)
            if changed:
                files_changed += 1
                if execute:
                    with open(p, "w", encoding="utf-8") as f:
                        f.write(new_text)

    print(f"Files changed: {files_changed}")
    if not execute:
        print("(dry run -- pass --execute to write)")

if __name__ == "__main__":
    main()