from __future__ import annotations

from datetime import datetime, timezone

from django.test import TestCase

from pobsync_backend.models import HostConfig, SnapshotRecord
from pobsync_backend.stats_summary import collect_dashboard_stats, collect_host_stats


class StatsSummaryTests(TestCase):
    def test_collect_dashboard_stats_sums_backup_data_across_hosts(self) -> None:
        web = HostConfig.objects.create(host="web-01", address="web-01.example.test")
        db = HostConfig.objects.create(host="db-01", address="db-01.example.test")
        self._snapshot(web, "20260519-021500Z__SCHED01", SnapshotRecord.Kind.SCHEDULED, allocated=100)
        self._snapshot(web, "20260519-031500Z__MANUAL1", SnapshotRecord.Kind.MANUAL, allocated=200)
        self._snapshot(db, "20260519-041500Z__SCHED02", SnapshotRecord.Kind.SCHEDULED, allocated=300)
        self._snapshot(db, "20260519-051500Z__BROKEN1", SnapshotRecord.Kind.INCOMPLETE, allocated=400)

        stats = collect_dashboard_stats(hosts=[web, db], global_config=None)

        self.assertEqual(stats["backup_data"]["scheduled"]["count"], 2)
        self.assertEqual(stats["backup_data"]["scheduled"]["allocated_size_bytes"], 400)
        self.assertEqual(stats["backup_data"]["manual"]["allocated_size_bytes"], 200)
        self.assertEqual(stats["backup_data"]["incomplete"]["allocated_size_bytes"], 400)
        self.assertEqual(stats["backup_data"]["total"]["count"], 4)
        self.assertEqual(stats["backup_data"]["total"]["allocated_size_bytes"], 1000)

    def test_collect_host_stats_sums_backup_data_by_snapshot_kind(self) -> None:
        host = HostConfig.objects.create(host="web-01", address="web-01.example.test")
        self._snapshot(host, "20260519-021500Z__SCHED01", SnapshotRecord.Kind.SCHEDULED, allocated=100)
        self._snapshot(host, "20260519-031500Z__SCHED02", SnapshotRecord.Kind.SCHEDULED, allocated=200)
        self._snapshot(host, "20260519-041500Z__MANUAL1", SnapshotRecord.Kind.MANUAL, allocated=300)
        self._snapshot(host, "20260519-051500Z__BROKEN1", SnapshotRecord.Kind.INCOMPLETE, allocated=400)

        stats = collect_host_stats(host=host)

        self.assertEqual(stats["backup_data"]["scheduled"]["count"], 2)
        self.assertEqual(stats["backup_data"]["scheduled"]["allocated_size_bytes"], 300)
        self.assertEqual(stats["backup_data"]["manual"]["allocated_size_bytes"], 300)
        self.assertEqual(stats["backup_data"]["incomplete"]["allocated_size_bytes"], 400)
        self.assertEqual(stats["backup_data"]["total"]["count"], 4)
        self.assertEqual(stats["backup_data"]["total"]["allocated_size_bytes"], 1000)

    def _snapshot(self, host: HostConfig, dirname: str, kind: str, *, allocated: int) -> SnapshotRecord:
        started_at = datetime.strptime(dirname.split("__", 1)[0], "%Y%m%d-%H%M%SZ").replace(tzinfo=timezone.utc)
        return SnapshotRecord.objects.create(
            host=host,
            kind=kind,
            dirname=dirname,
            path=f"/backups/{host.host}/{kind}/{dirname}",
            status="success",
            started_at=started_at,
            metadata={
                "stats": {
                    "storage": {
                        "snapshot": {
                            "apparent_size_bytes": allocated * 2,
                            "allocated_size_bytes": allocated,
                        }
                    }
                }
            },
        )