//! End-to-end tests against a real CalDAV server and a real iCal feed.
//!
//! The unit tests establish that the reconciler decides correctly. These
//! establish that the decisions survive the round trip through pimsync and a
//! server that rewrites what it stores — which is where every bug found by hand
//! during M1 actually lived.
//!
//! Radicale and pimsync both come from devbox, so `devbox run check` has them.
//! Outside that shell the tests report what is missing and pass, rather than
//! failing for a reason that has nothing to do with the code.

mod support;

use support::{Calcalist, Feed, Radicale};

/// An event with guests, an organiser and an alarm — the combination the
/// scheduling rules are about.
const MEETING: &str = "BEGIN:VCALENDAR\r\nVERSION:2.0\r\nPRODID:-//test//EN\r\n\
     BEGIN:VEVENT\r\nUID:meeting@work\r\nDTSTAMP:20260101T000000Z\r\n\
     DTSTART:20260910T090000Z\r\nDTEND:20260910T100000Z\r\nSUMMARY:Planning\r\n\
     ORGANIZER;CN=Chair:mailto:chair@example.com\r\n\
     ATTENDEE;CN=Guest;PARTSTAT=ACCEPTED:mailto:guest@example.com\r\n\
     BEGIN:VALARM\r\nACTION:DISPLAY\r\nTRIGGER:-PT15M\r\nDESCRIPTION:Soon\r\n\
     END:VALARM\r\nEND:VEVENT\r\nEND:VCALENDAR\r\n";

/// An event written straight into the aggregate, belonging to no source.
const HAND_WRITTEN: &str = "BEGIN:VCALENDAR\r\nVERSION:2.0\r\nPRODID:-//phone//EN\r\n\
     BEGIN:VEVENT\r\nUID:hand-written@phone\r\nDTSTAMP:20260101T000000Z\r\n\
     DTSTART:20260911T140000Z\r\nDTEND:20260911T150000Z\r\nSUMMARY:Dentist\r\n\
     END:VEVENT\r\nEND:VCALENDAR\r\n";

/// The same event, asking to be left where it was written.
const KEPT_LOCAL: &str = "BEGIN:VCALENDAR\r\nVERSION:2.0\r\nPRODID:-//phone//EN\r\n\
     BEGIN:VEVENT\r\nUID:kept@phone\r\nDTSTAMP:20260101T000000Z\r\n\
     DTSTART:20260912T140000Z\r\nDTEND:20260912T150000Z\r\nSUMMARY:Haircut\r\n\
     DESCRIPTION:Around the corner\\n\\n@local\r\nEND:VEVENT\r\nEND:VCALENDAR\r\n";

const HOLIDAY_FEED: &str = "BEGIN:VCALENDAR\r\nVERSION:2.0\r\nPRODID:-//feed//EN\r\n\
     BEGIN:VEVENT\r\nUID:newyear@feed\r\nDTSTAMP:20260101T000000Z\r\n\
     DTSTART;VALUE=DATE:20260101\r\nDTEND;VALUE=DATE:20260102\r\n\
     SUMMARY:New Year\r\nEND:VEVENT\r\nEND:VCALENDAR\r\n";

struct Fixture {
    _root: tempfile::TempDir,
    server: Radicale,
    _feed: Feed,
    calcalist: Calcalist,
}

/// A CalDAV source, a read-only feed, and a CalDAV target to aggregate into.
fn fixture() -> Option<Fixture> {
    let missing = support::missing_binaries();
    if !missing.is_empty() {
        eprintln!(
            "skipped: {} not on PATH; run under devbox",
            missing.join(", ")
        );
        return None;
    }

    let root = tempfile::tempdir().expect("temp");
    let server = Radicale::start(root.path());
    server.create_calendar("work");
    server.create_calendar("unified");
    server.put_event("work", "meeting.ics", MEETING);
    let feed = Feed::start(HOLIDAY_FEED.to_string());

    let config = format!(
        r#"
version = 1

[[endpoint]]
id = "work"
type = "caldav"
url = "{work}"
username = "{user}"
secret_command = "printf password"

[[endpoint]]
id = "published"
type = "caldav"
url = "{unified}"
username = "{user}"
secret_command = "printf password"

[[endpoint]]
id = "holidays"
type = "webcal"
url = "{feed}"

[[aggregate]]
id = "everything"
target = "published"
sources = ["work", "holidays"]
default_sink = "work"
"#,
        work = server.url("work"),
        unified = server.url("unified"),
        user = support::USER,
        feed = feed.url(),
    );

    let calcalist = Calcalist::new(root.path(), &config);
    Some(Fixture {
        _root: root,
        server,
        _feed: feed,
        calcalist,
    })
}

/// Both sources reach the target, and running again changes nothing.
///
/// Idempotence is the property that matters most: a cycle that is not a no-op
/// against unchanged input would rewrite every event on every run, and each
/// rewrite is a chance for the server to hand back something slightly different.
#[test]
fn a_cycle_converges_and_the_next_one_does_nothing() {
    let Some(fixture) = fixture() else { return };

    let first = fixture.calcalist.run(&["sync"]);
    assert!(
        first.succeeded(),
        "first sync failed\n{}\n{}",
        first.stdout,
        first.stderr
    );

    let published = fixture.server.stored("unified");
    assert_eq!(
        published.len(),
        2,
        "both sources should arrive: {published:?}"
    );
    let all = published.join("\n");
    assert!(all.contains("Planning"), "{all}");
    assert!(all.contains("New Year"), "{all}");
    // Provenance travels with each mirror, so the aggregate knows where its
    // events came from without consulting the state file.
    assert!(all.contains("X-CALCALIST-SOURCE:work"), "{all}");
    assert!(all.contains("X-CALCALIST-SOURCE:holidays"), "{all}");

    let second = fixture.calcalist.run(&["sync"]);
    assert!(
        second.succeeded(),
        "second sync failed\n{}\n{}",
        second.stdout,
        second.stderr
    );
    assert!(
        second.stdout.contains("everything: 0 mirrored"),
        "the second cycle should be a no-op:\n{}",
        second.stdout
    );
    assert_eq!(
        fixture.server.stored("unified"),
        published,
        "the second cycle rewrote the target"
    );
}

/// The scheduling rule, checked against what actually reached the server.
///
/// A CalDAV server has no portable way to be told not to send invitations, so
/// inertness is structural: the mirror carries the guest list as data and not as
/// live scheduling properties. The alarm is the deliberate exception — stripping
/// it would destroy every reminder in the one calendar the user subscribes to.
///
/// Radicale implements no scheduling of its own, so this asserts on the bytes
/// stored rather than on a mail sink: with nothing to send mail, a quiet SMTP
/// port would prove nothing about the transform.
#[test]
fn a_mirror_carries_no_live_scheduling_properties() {
    let Some(fixture) = fixture() else { return };

    let run = fixture.calcalist.run(&["sync"]);
    assert!(
        run.succeeded(),
        "sync failed\n{}\n{}",
        run.stdout,
        run.stderr
    );

    let mirror = fixture
        .server
        .stored("unified")
        .into_iter()
        .find(|item| item.contains("Planning"))
        .expect("the meeting should have been mirrored");

    for property in ["ATTENDEE;", "ATTENDEE:", "ORGANIZER;", "ORGANIZER:"] {
        assert!(
            !mirror
                .lines()
                .any(|line| line.trim_start().starts_with(property)),
            "a live {property} reached the aggregate:\n{mirror}"
        );
    }
    // The guests are still there, as something nothing will act on.
    assert!(
        mirror.contains("X-CALCALIST-ATTENDEES"),
        "the guest list was lost:\n{mirror}"
    );
    assert!(
        mirror.contains("guest@example.com"),
        "the guest list was lost:\n{mirror}"
    );
    assert!(
        mirror.contains("BEGIN:VALARM") && mirror.contains("TRIGGER:-PT15M"),
        "the alarm did not survive:\n{mirror}"
    );

    // The source keeps its scheduling properties: only the aggregate is inert.
    let source = fixture
        .server
        .stored("work")
        .into_iter()
        .find(|item| item.contains("Planning"))
        .expect("the meeting should still be in its source");
    assert!(source.contains("ATTENDEE"), "{source}");
    assert!(source.contains("ORGANIZER"), "{source}");
}

/// A dry run must reach the servers to be worth anything, and change nothing.
#[test]
fn a_dry_run_reports_without_touching_anything() {
    let Some(fixture) = fixture() else { return };

    let dry = fixture.calcalist.run(&["sync", "--dry-run"]);
    assert!(
        dry.succeeded(),
        "dry run failed\n{}\n{}",
        dry.stdout,
        dry.stderr
    );
    assert!(
        dry.stdout.contains("everything: 2 mirrored"),
        "the dry run should have seen both sources:\n{}",
        dry.stdout
    );
    assert!(
        fixture.server.stored("unified").is_empty(),
        "the dry run published events"
    );

    // And the real cycle that follows is not confused by it.
    let real = fixture.calcalist.run(&["sync"]);
    assert!(
        real.succeeded(),
        "sync after a dry run failed\n{}\n{}",
        real.stdout,
        real.stderr
    );
    assert_eq!(fixture.server.stored("unified").len(), 2);
}

/// Removing an endpoint used to leave its events sitting in the state directory
/// with nothing managing them. They are now reported, and removed on request.
#[test]
fn a_retired_endpoints_mirror_is_reported_and_then_removed() {
    let Some(fixture) = fixture() else { return };

    assert!(fixture.calcalist.run(&["sync"]).succeeded());
    let mirror = fixture.calcalist.state.join("calcalist/vdir/holidays");
    assert!(mirror.is_dir(), "the feed should have been mirrored");

    // The feed is dropped from the configuration, as a user would drop it.
    std::fs::write(
        &fixture.calcalist.config,
        fixture.calcalist.config_without_feed(),
    )
    .expect("rewrite config");

    let listed = fixture.calcalist.run(&["prune"]);
    assert!(listed.succeeded(), "{}", listed.stderr);
    assert!(
        listed.stdout.contains("would remove") && listed.stdout.contains("holidays"),
        "prune should say what it found:\n{}",
        listed.stdout
    );
    assert!(mirror.is_dir(), "listing must not delete anything");

    let removed = fixture.calcalist.run(&["prune", "--force"]);
    assert!(removed.succeeded(), "{}", removed.stderr);
    assert!(!mirror.exists(), "the orphaned mirror should be gone");
}

/// An aggregate with no `default_sink` leaves events created in it alone.
///
/// This is how a target calendar keeps events of its own: with nowhere
/// configured to file a new event, calcalist refuses to guess rather than
/// picking a source, so the event simply stays where it was written. Worth
/// pinning, because "left alone" has to hold on every subsequent cycle too —
/// an event that survived the first one and was swept up by the second would
/// be worse than never having worked.
#[test]
fn an_event_created_in_a_sinkless_aggregate_stays_where_it_is() {
    let Some(fixture) = fixture() else { return };

    // The fixture's aggregate has a default_sink; take it away.
    let sinkless = std::fs::read_to_string(&fixture.calcalist.config)
        .expect("read config")
        .replace("default_sink = \"work\"\n", "");
    std::fs::write(&fixture.calcalist.config, sinkless).expect("rewrite config");

    assert!(fixture.calcalist.run(&["sync"]).succeeded());

    // Now add an event by hand, as a calendar app would.
    fixture
        .server
        .put_event("unified", "dentist.ics", HAND_WRITTEN);

    for cycle in 1..=3 {
        let run = fixture.calcalist.run(&["sync"]);
        assert!(
            run.succeeded(),
            "cycle {cycle} failed\n{}\n{}",
            run.stdout,
            run.stderr
        );

        let published = fixture.server.stored("unified");
        assert!(
            published.iter().any(|item| item.contains("Dentist")),
            "cycle {cycle}: the hand-written event was removed:\n{published:?}"
        );
        // It never reaches a source: there is nowhere it was told to go.
        assert!(
            !fixture
                .server
                .stored("work")
                .iter()
                .any(|item| item.contains("Dentist")),
            "cycle {cycle}: the hand-written event leaked into the source"
        );
    }
}

/// `@local` opts one event out of a default sink that would otherwise take it.
///
/// The marker has to survive, unlike every other one: it is stripped markers
/// that have done their job on arrival, whereas this event never leaves, so the
/// next cycle has to be able to reach the same decision.
#[test]
fn the_local_marker_keeps_an_event_out_of_a_configured_sink() {
    let Some(fixture) = fixture() else { return };

    assert!(fixture.calcalist.run(&["sync"]).succeeded());
    fixture
        .server
        .put_event("unified", "haircut.ics", KEPT_LOCAL);

    for cycle in 1..=3 {
        let run = fixture.calcalist.run(&["sync"]);
        assert!(
            run.succeeded(),
            "cycle {cycle} failed\n{}\n{}",
            run.stdout,
            run.stderr
        );
        assert!(
            run.stdout.contains("1 event(s) kept local"),
            "cycle {cycle} should report it as kept, not skipped:\n{}",
            run.stdout
        );

        let kept = fixture
            .server
            .stored("unified")
            .into_iter()
            .find(|item| item.contains("Haircut"))
            .expect("the event should still be in the aggregate");
        // Stripping it would let the default sink claim the event next cycle.
        assert!(kept.contains("@local"), "cycle {cycle}: {kept}");

        assert!(
            !fixture
                .server
                .stored("work")
                .iter()
                .any(|item| item.contains("Haircut")),
            "cycle {cycle}: it reached the default sink anyway"
        );
    }
}

/// Discovery, against a server that really has two calendars.
///
/// The command exists because the CalDAV `url` must name the collection exactly
/// and providers rarely show it. What it prints therefore has to be usable
/// as-is, which is what the parse-back below actually checks.
#[test]
fn discover_lists_the_servers_calendars_as_pasteable_config() {
    let Some(fixture) = fixture() else { return };

    let run = fixture.calcalist.run(&[
        "discover",
        &format!(
            "http://127.0.0.1:{}/{}/",
            fixture.server.port,
            support::USER
        ),
        "--username",
        support::USER,
        "--secret-command",
        "printf password",
    ]);
    assert!(
        run.succeeded(),
        "discover failed\n{}\n{}",
        run.stdout,
        run.stderr
    );

    assert!(run.stdout.contains("id = \"work\""), "{}", run.stdout);
    assert!(run.stdout.contains("id = \"unified\""), "{}", run.stdout);
    // The URL has to come back absolute, not as the bare path pimsync reports.
    assert!(
        run.stdout
            .contains(&format!("http://127.0.0.1:{}/", fixture.server.port)),
        "{}",
        run.stdout
    );

    // The point of the command: what it prints is valid configuration.
    let config = format!("version = 1\n{}", run.stdout);
    let parsed: toml::Value = toml::from_str(&config).expect("the output should be valid TOML");
    let endpoints = parsed["endpoint"].as_array().expect("endpoints");
    assert_eq!(endpoints.len(), 2, "{}", run.stdout);
    assert_eq!(endpoints[0]["type"].as_str(), Some("caldav"));
    assert_eq!(
        endpoints[0]["secret_command"].as_str(),
        Some("printf password")
    );
}

/// An unreachable server has to say so rather than print an empty result that
/// looks like "this server has no calendars".
#[test]
fn discover_reports_a_server_it_cannot_reach() {
    if !support::missing_binaries().is_empty() {
        eprintln!("skipped: run under devbox");
        return;
    }
    let root = tempfile::tempdir().expect("temp");
    let calcalist = Calcalist::new(root.path(), "version = 1\n");

    // Port 9 is discard: it refuses or blackholes, and nothing listens for DAV.
    let run = calcalist.run(&[
        "discover",
        "http://127.0.0.1:9/calendars/me/",
        "--username",
        "me",
    ]);

    assert!(
        !run.succeeded(),
        "it should not claim success\n{}",
        run.stdout
    );
    assert!(
        !run.stderr.is_empty(),
        "the failure should be explained: {run:?}",
        run = run.stderr
    );
}

/// The lock is what stops a timer firing into a hand-run cycle.
///
/// The lock is taken here rather than by racing two real syncs, which would be
/// timing-dependent and would pass by accident most of the time.
#[test]
fn a_second_cycle_is_refused_while_one_is_running() {
    let Some(fixture) = fixture() else { return };
    assert!(fixture.calcalist.run(&["sync"]).succeeded());

    let lock_path = fixture.calcalist.state.join("calcalist/lock");
    let held = std::fs::OpenOptions::new()
        .read(true)
        .write(true)
        .open(&lock_path)
        .expect("the lock file should exist after a cycle");
    rustix::fs::flock(&held, rustix::fs::FlockOperation::NonBlockingLockExclusive)
        .expect("the test should be able to take the lock");

    let refused = fixture.calcalist.run(&["sync"]);
    assert!(!refused.succeeded(), "{}", refused.stdout);
    assert!(
        refused.stderr.contains("already running"),
        "the refusal should say why: {}",
        refused.stderr
    );

    drop(held);
    assert!(
        fixture.calcalist.run(&["sync"]).succeeded(),
        "the lock should be free again"
    );
}