#!/usr/bin/env python3
"""
Auto-Merger — merges approved PRs via squash merge.

Checks:
1. PR has at least 1 approval review
2. PR is mergeable
3. No pending change requests
4. From mimo swarm (safety: only auto-merge mimo PRs)

Squash merges, closes issue, cleans up branch.
"""

import json
import os
import urllib.request
import urllib.error
from datetime import datetime, timezone

GITEA_URL = "https://forge.alexanderwhitestone.com"
TOKEN_FILE = os.path.expanduser("~/.config/gitea/token")
LOG_DIR = os.path.expanduser("~/.hermes/mimo-swarm/logs")
REPO = "Timmy_Foundation/the-nexus"


def load_token():
    with open(TOKEN_FILE) as f:
        return f.read().strip()


def api_get(path, token):
    url = f"{GITEA_URL}/api/v1{path}"
    req = urllib.request.Request(url, headers={
        "Authorization": f"token {token}",
        "Accept": "application/json",
    })
    try:
        with urllib.request.urlopen(req, timeout=30) as resp:
            return json.loads(resp.read())
    except:
        return None


def api_post(path, token, data=None):
    url = f"{GITEA_URL}/api/v1{path}"
    body = json.dumps(data or {}).encode()
    req = urllib.request.Request(url, data=body, headers={
        "Authorization": f"token {token}",
        "Content-Type": "application/json",
    }, method="POST")
    try:
        with urllib.request.urlopen(req, timeout=30) as resp:
            return resp.status, resp.read().decode()
    except urllib.error.HTTPError as e:
        return e.code, e.read().decode() if e.fp else ""


def api_delete(path, token):
    url = f"{GITEA_URL}/api/v1{path}"
    req = urllib.request.Request(url, headers={
        "Authorization": f"token {token}",
    }, method="DELETE")
    try:
        with urllib.request.urlopen(req, timeout=30) as resp:
            return resp.status
    except:
        return 500


def log(msg):
    ts = datetime.now(timezone.utc).strftime("%Y-%m-%dT%H:%M:%SZ")
    print(f"[{ts}] {msg}")
    log_file = os.path.join(LOG_DIR, f"merger-{datetime.now().strftime('%Y%m%d')}.log")
    with open(log_file, "a") as f:
        f.write(f"[{ts}] {msg}\n")


def main():
    token = load_token()
    log("=" * 50)
    log("AUTO-MERGER — checking approved PRs")

    prs = api_get(f"/repos/{REPO}/pulls?state=open&limit=20", token)
    if not prs:
        log("No open PRs")
        return

    merged = 0
    skipped = 0

    for pr in prs:
        pr_num = pr["number"]
        head_ref = pr.get("head", {}).get("ref", "")
        body = pr.get("body", "") or ""
        mergeable = pr.get("mergeable", False)

        # Only auto-merge mimo PRs
        is_mimo = "mimo" in head_ref.lower() or "Automated by mimo" in body
        if not is_mimo:
            continue

        # Check reviews
        reviews = api_get(f"/repos/{REPO}/pulls/{pr_num}/reviews", token) or []
        approvals = [r for r in reviews if r.get("state") == "APPROVED"]
        changes_requested = [r for r in reviews if r.get("state") == "CHANGES_REQUESTED"]

        if changes_requested:
            log(f"  SKIP #{pr_num}: has change requests")
            skipped += 1
            continue

        if not approvals:
            log(f"  SKIP #{pr_num}: no approvals yet")
            skipped += 1
            continue

        # Attempt squash merge
        merge_title = pr["title"]
        merge_msg = f"Squash merge #{pr_num}: {merge_title}\n\n{body}"

        status, response = api_post(f"/repos/{REPO}/pulls/{pr_num}/merge", token, {
            "Do": "squash",
            "MergeTitleField": merge_title,
            "MergeMessageField": f"Closes #{pr_num}\n\nAutomated merge by mimo swarm.",
        })

        if status == 200:
            merged += 1
            log(f"  MERGED #{pr_num}: {merge_title[:50]}")

            # Delete the branch
            if head_ref and head_ref != "main":
                api_delete(f"/repos/{REPO}/git/refs/heads/{head_ref}", token)
                log(f"  Deleted branch: {head_ref}")
        else:
            log(f"  MERGE FAILED #{pr_num}: status={status}, {response[:200]}")

    log(f"Merge complete: {merged} merged, {skipped} skipped")


if __name__ == "__main__":
    main()