#!/usr/bin/env python3
"""
page_ls.py — show what a space holds. Offline.

The tree, the titles, and one state tag per page. The tag is the only place
this layer acknowledges that a wiki exists, and it reads it the way the issue
index reads `origin:` — as an opaque fact recorded by somebody else:

    local     never published; a complete state, not a pending one
    synced    published, and the file matches what was pushed
    ahead     published, and the local file has changed since
    ?         published, but nothing recorded what was pushed

Usage:
    page_ls.py [--space SPACE] [--prefix TITLE] [--titles] [--out DIR]
"""
import argparse
import os
import sys

sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
import page  # noqa: E402


def die(msg, code=1):
    sys.stderr.write("%s: %s\n" % (os.path.basename(sys.argv[0]), msg))
    sys.exit(code)


def state_of(space_dir, relpath, e):
    if not e.get("sub_url"):
        return "local"
    pushed = e.get("pushed")
    if not pushed:
        return "?"
    full = os.path.join(space_dir, relpath)
    if not os.path.isfile(full):
        return "missing"
    with open(full, encoding="utf-8") as f:
        return "synced" if page.body_hash(f.read()) == pushed else "ahead"


def main():
    ap = argparse.ArgumentParser()
    ap.add_argument("--space", default="local")
    ap.add_argument("--prefix", default="", help="only titles at or under this")
    ap.add_argument("--titles", action="store_true",
                    help="print one title per line and nothing else")
    ap.add_argument("--out", help="wiki cache root (default: <repo>/tmp/wiki)")
    a = ap.parse_args()

    root = a.out or page.WIKI_ROOT
    space_dir = page.space_root(a.space, root)
    # "Does not exist" and "is empty" are different answers and get different
    # messages — an empty space is a space somebody made on purpose.
    if not os.path.isdir(space_dir):
        die("no such space: %s (looked in %s)" % (a.space, space_dir))

    manifest = page.load_manifest(a.space, root)
    pages = (page.children_of(manifest, a.prefix) if a.prefix
             else page.sorted_pages(manifest))
    if not pages:
        print("space %s is empty" % a.space if not a.prefix
              else "nothing at or under %r" % a.prefix)
        return 0

    if a.titles:
        for _, e in pages:
            print(e.get("title", ""))
        return 0

    sub = {p: e for p, e in pages}
    view = dict(manifest, pages=sub)
    for line in page.tree_lines(view, mark=lambda p, e: state_of(space_dir, p, e)):
        print(line)

    counts = {}
    for p, e in pages:
        s = state_of(space_dir, p, e)
        counts[s] = counts.get(s, 0) + 1
    print("\n%d page(s): %s" % (len(pages),
                                ", ".join("%d %s" % (v, k)
                                          for k, v in sorted(counts.items()))))
    return 0


if __name__ == "__main__":
    sys.exit(main())