#!/usr/bin/env python3
"""Daily Wikipedia pageviews for a list of articles, as CSV.

Uses the public Wikimedia Pageviews REST API (no API key). Standard library only.

  python3 wikipageviews.py --start 20260901 --end 20260930 "Python_(programming_language)" "Rust_(programming_language)"
"""
import argparse, csv, json, sys, time, urllib.error, urllib.parse, urllib.request

UA = "wikipageviews-script/0.1 (static download; contact via the page it came from)"
ROOT = "https://wikimedia.org/api/rest_v1/metrics/pageviews/per-article"


def views(article, project="en.wikipedia", granularity="daily", start="20260901", end="20260930", access="all-access", agent="user"):
    enc = urllib.parse.quote(article.replace(" ", "_"), safe="")
    url = f"{ROOT}/{project}/{access}/{agent}/{enc}/{granularity}/{start}/{end}"
    req = urllib.request.Request(url, headers={"User-Agent": UA})
    try:
        with urllib.request.urlopen(req, timeout=30) as r:
            data = json.load(r)
    except urllib.error.HTTPError as e:
        if e.code == 404:
            return []
        raise
    return [(i["timestamp"][:8], i["views"]) for i in data["items"]]


def main():
    p = argparse.ArgumentParser(description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter)
    p.add_argument("articles", nargs="*", default=["Python_(programming_language)"])
    p.add_argument("--project", default="en.wikipedia")
    p.add_argument("--start", default="20260901")
    p.add_argument("--end", default="20260930")
    p.add_argument("--granularity", default="daily", choices=["daily", "monthly"])
    a = p.parse_args()
    w = csv.writer(sys.stdout)
    w.writerow(["article", "date", "views"])
    for art in a.articles:
        for date, n in views(art, a.project, a.granularity, a.start, a.end):
            w.writerow([art, date, n])
        time.sleep(0.2)


if __name__ == "__main__":
    main()