#!/usr/bin/env perl
use strict;
use warnings;
use Test::More;
use DateTime;
use FindBin qw($RealBin);
use lib "$RealBin/../lib";
use Mnemosyne::Schedule;

# --- helpers ---

sub dt { DateTime->new(year => $_[0], month => $_[1], day => $_[2]) }

sub task {
    my %h = (id => 1, active => 1, created_at => '2026-01-01T00:00:00Z', @_);
    return \%h;
}

sub status {
    my ($task, $today, %opts) = @_;
    return Mnemosyne::Schedule->status($task, $today, %opts);
}

# ============================================================
# monthly_date
# ============================================================
# June 2026: 30 days.  July 2026: 31 days.  Feb 2026: 28 days.

subtest 'monthly_date — basic' => sub {
    my $t = task(class => 'monthly_date', day_of_month => 15);

    is status($t, dt(2026,6,15)),                          'due',         'due on the day';
    is status($t, dt(2026,6,16)),                          'overdue',     'overdue day after';
    is status($t, dt(2026,6,20)),                          'overdue',     'overdue a week later';
    is status($t, dt(2026,6,15), last_completed_dt => dt(2026,6,15)),
                                                           'not_relevant','done today → not relevant (Jul 15 is 30 days out)';

    # Upcoming: Jun 15 is 7 days from Jun 8 (= horizon), 6 days from Jun 9
    is status($t, dt(2026,6,8),  last_completed_dt => dt(2026,5,15)), 'upcoming',     '7 days out = within horizon';
    is status($t, dt(2026,6,9),  last_completed_dt => dt(2026,5,15)), 'upcoming',     '6 days out';
    is status($t, dt(2026,6,7),  last_completed_dt => dt(2026,5,15)), 'not_relevant', '8 days out = beyond horizon';

    # Completed this cycle → upcoming next month
    is status($t, dt(2026,6,20), last_completed_dt => dt(2026,6,15)), 'not_relevant', 'completed; Jul 15 is 25 days out';
};

subtest 'monthly_date — short-month clamping' => sub {
    # day=31: June has 30 days, so occurrence is Jun 30
    my $t31 = task(class => 'monthly_date', day_of_month => 31);
    is status($t31, dt(2026,6,30)),                     'due',     'day=31 in June clamps to Jun 30 → due';
    is status($t31, dt(2026,6,29), last_completed_dt => dt(2026,5,31)),
                                                        'upcoming','day=31 in June: Jun 30 is 1 day out (May 31 done)';
    is status($t31, dt(2026,7,1)),                      'overdue', 'day=31: Jul 1, Jun 30 missed';
    is status($t31, dt(2026,7,31)),                     'due',     'day=31 in July (31 days) → Jul 31 due';

    # day=29: Feb 2026 has 28 days
    my $t29 = task(class => 'monthly_date', day_of_month => 29);
    is status($t29, dt(2026,2,28)),                     'due',     'day=29 in Feb 2026 clamps to Feb 28 → due';
    is status($t29, dt(2026,3,1)),                      'overdue', 'day=29: Mar 1, Feb 28 missed';
    is status($t29, dt(2026,3,29)),                     'due',     'day=29 in March (31 days) → Mar 29 due';

    # day=31: Apr has 30 days → clamps to Apr 30
    my $t31b = task(class => 'monthly_date', day_of_month => 31);
    is status($t31b, dt(2026,4,30)),                    'due',     'day=31 in April clamps to Apr 30 → due';
};

subtest 'monthly_date — pre-creation guard' => sub {
    # Task created Jun 1; previous occurrence (May 15) is before creation → not overdue
    my $t = task(
        class        => 'monthly_date',
        day_of_month => 15,
        created_at   => '2026-06-01T00:00:00Z',
    );
    # today = Jun 8: curr_occ would be May 15 (before created_at) → treat as done → upcoming Jun 15
    is status($t, dt(2026,6,8)), 'upcoming', 'pre-creation occurrence not flagged overdue';
    is status($t, dt(2026,6,7)), 'not_relevant', 'pre-creation; Jun 15 still 8 days out';
};

subtest 'monthly_date — inactive' => sub {
    my $t = task(class => 'monthly_date', day_of_month => 15, active => 0);
    is status($t, dt(2026,6,15)), 'inactive', 'inactive task';
};

# ============================================================
# monthly_weekday
# ============================================================
# June 2026: Jun 1 = Monday
#   4th Monday = Jun 22
#   5th/last Monday = Jun 29
# July 2026: Jul 1 = Wednesday
#   1st Monday = Jul 6
# Feb 2026: Feb 1 = Sunday
#   1st Friday = Feb 6
#   last Friday = Feb 27

subtest 'monthly_weekday — 4th Monday June 2026' => sub {
    # weekday 1=Monday, ordinal 4
    my $t = task(class => 'monthly_weekday', weekday => 1, ordinal => 4);

    is status($t, dt(2026,6,22)),                          'due',         '4th Monday Jun = Jun 22, due';
    is status($t, dt(2026,6,21), last_completed_dt => dt(2026,5,25)),
                                                           'upcoming',    'Jun 21: Jun 22 is 1 day out';
    is status($t, dt(2026,6,23)),                          'overdue',     'Jun 23: Jun 22 missed';
    is status($t, dt(2026,6,22), last_completed_dt => dt(2026,6,22)),
                                                           'not_relevant','completed Jun 22; Jul 27 is far';
};

subtest 'monthly_weekday — last Monday June 2026' => sub {
    my $t = task(class => 'monthly_weekday', weekday => 1, ordinal => -1);

    is status($t, dt(2026,6,29)),                          'due',     'last Monday Jun = Jun 29, due';
    is status($t, dt(2026,6,28), last_completed_dt => dt(2026,5,25)),
                                                           'upcoming', 'Jun 28: Jun 29 is 1 day out';
    is status($t, dt(2026,6,30)),                          'overdue',  'Jun 30: Jun 29 missed';
};

subtest 'monthly_weekday — 1st Monday July 2026' => sub {
    my $t = task(class => 'monthly_weekday', weekday => 1, ordinal => 1);
    is status($t, dt(2026,7,6)),  'due',     '1st Monday Jul = Jul 6, due';
    is status($t, dt(2026,7,5),  last_completed_dt => dt(2026,6,1)),
                                  'upcoming', 'Jul 5: Jul 6 is 1 day out';
    is status($t, dt(2026,7,7)),  'overdue',  'Jul 7: Jul 6 missed';
};

subtest 'monthly_weekday — last Friday Feb 2026' => sub {
    # Feb 2026: last day = Feb 28 (Saturday). Last Friday = Feb 27.
    my $t = task(class => 'monthly_weekday', weekday => 5, ordinal => -1);
    is status($t, dt(2026,2,27)), 'due',     'last Friday Feb = Feb 27, due';
    is status($t, dt(2026,2,28)), 'overdue', 'Feb 28: Feb 27 missed';
};

subtest 'monthly_weekday — 1st Friday Feb 2026' => sub {
    # Feb 1 = Sunday; 1st Friday = Feb 6
    my $t = task(class => 'monthly_weekday', weekday => 5, ordinal => 1);
    is status($t, dt(2026,2,6)),  'due',     '1st Friday Feb = Feb 6, due';
    is status($t, dt(2026,2,5),  last_completed_dt => dt(2026,1,2)),
                                  'upcoming', 'Feb 5: Feb 6 is 1 day out';
    is status($t, dt(2026,2,7)),  'overdue',  'Feb 7: Feb 6 missed';
};

# ============================================================
# every_n_period
# ============================================================

subtest 'every_n_period — every 2 weeks from 2026-01-01' => sub {
    # Occurrences: Jan 1, Jan 15, Jan 29, Feb 12, ...
    my $t = task(class => 'every_n_period', interval_n => 2, period_unit => 'week',
                 anchor_date => '2026-01-01');

    is status($t, dt(2026,1,15)),                               'due',         'Jan 15 occurrence due';
    is status($t, dt(2026,1,16)),                               'overdue',     'Jan 16: Jan 15 missed';
    is status($t, dt(2026,1,14), last_completed_dt => dt(2026,1,1)),
                                                                'upcoming',    'Jan 14: Jan 15 is 1 day out';
    # Jan 15 done; Jan 29 is 14 days away — beyond default horizon of 7
    is status($t, dt(2026,1,15), last_completed_dt => dt(2026,1,15)),
                                                                'not_relevant','Jan 15 done; Jan 29 is 14 days out > horizon';

    # Check with wider horizon
    is status($t, dt(2026,1,15),
              last_completed_dt   => dt(2026,1,15),
              upcoming_horizon    => 14),
                                                                'upcoming',    'Jan 15 done; Jan 29 upcoming with horizon=14';

    is status($t, dt(2026,1,29)),                               'due',         'Jan 29 occurrence due';
    is status($t, dt(2026,2,12)),                               'due',         'Feb 12 occurrence due';
};

subtest 'every_n_period — anchor in future' => sub {
    my $t = task(class => 'every_n_period', interval_n => 1, period_unit => 'week',
                 anchor_date => '2026-06-15');
    is status($t, dt(2026,6,8)),  'upcoming',     'anchor Jun 15 is 7 days out';
    is status($t, dt(2026,6,7)),  'not_relevant', 'anchor Jun 15 is 8 days out';
    is status($t, dt(2026,6,15)), 'due',          'anchor date itself is due';
};

subtest 'every_n_period — every 1 month from 2026-01-31 (short-month clamping)' => sub {
    # Occurrences: Jan 31, Feb 28 (clamp), Mar 31, Apr 30 (clamp)
    my $t = task(class => 'every_n_period', interval_n => 1, period_unit => 'month',
                 anchor_date => '2026-01-31');

    is status($t, dt(2026,2,28)),                               'due',     'Feb 28 (clamped from 31)';
    is status($t, dt(2026,3,1)),                                'overdue', 'Mar 1: Feb 28 missed';
    is status($t, dt(2026,3,31)),                               'due',     'Mar 31 due';
    is status($t, dt(2026,4,30)),                               'due',     'Apr 30 (clamped from 31)';
    is status($t, dt(2026,5,31)),                               'due',     'May 31 due';

    is status($t, dt(2026,2,27), last_completed_dt => dt(2026,1,31)),
                                                                'upcoming', 'Jan 31 done; Feb 28 is 1 day out';
};

subtest 'every_n_period — every 3 months' => sub {
    # Anchor Jan 15: occurrences Jan 15, Apr 15, Jul 15, Oct 15
    my $t = task(class => 'every_n_period', interval_n => 3, period_unit => 'month',
                 anchor_date => '2026-01-15');

    is status($t, dt(2026,4,15)),                               'due',     'Apr 15 occurrence';
    is status($t, dt(2026,4,14), last_completed_dt => dt(2026,1,15)),
                                                                'upcoming', 'Apr 14: Apr 15 is 1 day out';
    is status($t, dt(2026,4,16)),                               'overdue',  'Apr 16: Apr 15 missed';
};

subtest 'every_n_period — every 3 days' => sub {
    my $t = task(class => 'every_n_period', interval_n => 3, period_unit => 'day',
                 anchor_date => '2026-06-01');
    # Occurrences: Jun 1, Jun 4, Jun 7, Jun 10 ...
    is status($t, dt(2026,6,4)),                                'due',     'Jun 4 due';
    is status($t, dt(2026,6,5)),                                'overdue', 'Jun 5: Jun 4 missed';
    is status($t, dt(2026,6,3), last_completed_dt => dt(2026,6,1)),
                                                                'upcoming', 'Jun 3: Jun 4 is 1 day out';
};

# ============================================================
# interval (reset-on-completion)
# ============================================================

subtest 'interval — seeded from created_at' => sub {
    # interval=30, created May 1: next_due = May 31
    my $t = task(class => 'interval', interval_days => 30,
                 created_at => '2026-05-01T00:00:00Z');

    is status($t, dt(2026,5,31)), 'due',          'May 31 = created + 30 days';
    is status($t, dt(2026,6,1)),  'overdue',       'Jun 1 is past due';
    is status($t, dt(2026,5,30)), 'upcoming',      'May 30: due tomorrow';
    is status($t, dt(2026,5,24)), 'upcoming',      'May 24: due in 7 days (= horizon)';
    is status($t, dt(2026,5,23)), 'not_relevant',  'May 23: due in 8 days';
    is status($t, dt(2026,5,1)),  'not_relevant',  'created today: due in 30 days';
};

subtest 'interval — reset on completion' => sub {
    my $t = task(class => 'interval', interval_days => 30,
                 created_at => '2026-01-01T00:00:00Z');

    # last_comp = May 15 → next_due = Jun 14
    is status($t, dt(2026,6,14), last_completed_dt => dt(2026,5,15)), 'due',      'Jun 14 = May 15 + 30';
    is status($t, dt(2026,6,15), last_completed_dt => dt(2026,5,15)), 'overdue',  'Jun 15: past due';
    is status($t, dt(2026,6,13), last_completed_dt => dt(2026,5,15)), 'upcoming', 'Jun 13: due tomorrow';

    # Completion resets: last_comp = Jun 14 → next_due = Jul 14
    is status($t, dt(2026,7,14), last_completed_dt => dt(2026,6,14)), 'due',      'Jul 14 = Jun 14 + 30';
};

subtest 'interval — zero days since creation' => sub {
    # interval=7, created Jun 10 → next_due = Jun 17 (7 days out = exactly at default horizon)
    my $t = task(class => 'interval', interval_days => 7,
                 created_at => '2026-06-10T00:00:00Z');
    is status($t, dt(2026,6,10)),                        'upcoming',     'created today: Jun 17 is 7 days out, within horizon';
    is status($t, dt(2026,6,10), upcoming_horizon => 6), 'not_relevant', '7 days out > horizon=6';
};

# ============================================================
# floating
# ============================================================

subtest 'floating — high priority' => sub {
    my $t = task(class => 'floating', priority => 'high', created_at => '2026-06-01T00:00:00Z');
    is status($t, dt(2026,6,1)),  'due', 'high: shown on day 0';
    is status($t, dt(2026,6,10)), 'due', 'high: shown every day';
    is status($t, dt(2026,7,4)),  'due', 'high: shown weeks later';
};

subtest 'floating — medium priority (every 3 days)' => sub {
    my $t = task(class => 'floating', priority => 'medium', created_at => '2026-06-01T00:00:00Z');
    # day 0 (Jun 1): 0 % 3 == 0 → shown
    # day 1 (Jun 2): 1 % 3 != 0 → not shown
    # day 2 (Jun 3): 2 % 3 != 0 → not shown
    # day 3 (Jun 4): 3 % 3 == 0 → shown
    # day 6 (Jun 7): 6 % 3 == 0 → shown
    is status($t, dt(2026,6,1),  medium_float_days => 3), 'due',          'medium day 0';
    is status($t, dt(2026,6,2),  medium_float_days => 3), 'not_relevant', 'medium day 1';
    is status($t, dt(2026,6,3),  medium_float_days => 3), 'not_relevant', 'medium day 2';
    is status($t, dt(2026,6,4),  medium_float_days => 3), 'due',          'medium day 3';
    is status($t, dt(2026,6,7),  medium_float_days => 3), 'due',          'medium day 6';
    is status($t, dt(2026,6,8),  medium_float_days => 3), 'not_relevant', 'medium day 7';
};

subtest 'floating — low priority (weekly, rotated by task_id)' => sub {
    # shown when (days_since_created + task_id) % 7 == 0
    # task_id=6, created Jun 1:
    #   day 0: (0+6)%7=6 → not shown
    #   day 1: (1+6)%7=0 → shown
    my $t6 = task(id => 6, class => 'floating', priority => 'low', created_at => '2026-06-01T00:00:00Z');
    is status($t6, dt(2026,6,1)), 'not_relevant', 'low id=6 day 0: not shown';
    is status($t6, dt(2026,6,2)), 'due',          'low id=6 day 1: shown';
    is status($t6, dt(2026,6,3)), 'not_relevant', 'low id=6 day 2: not shown';
    is status($t6, dt(2026,6,9)), 'due',          'low id=6 day 8: shown (8+6=14, 14%7=0)';

    # task_id=7, created Jun 1:
    #   day 0: (0+7)%7=0 → shown
    my $t7 = task(id => 7, class => 'floating', priority => 'low', created_at => '2026-06-01T00:00:00Z');
    is status($t7, dt(2026,6,1)), 'due',          'low id=7 day 0: shown';
    is status($t7, dt(2026,6,2)), 'not_relevant', 'low id=7 day 1: not shown';
    is status($t7, dt(2026,6,8)), 'due',          'low id=7 day 7: shown';
};

subtest 'floating — inactive' => sub {
    my $t = task(class => 'floating', priority => 'high', active => 0);
    is status($t, dt(2026,6,1)), 'inactive', 'inactive floating task';
};

# ============================================================
# DST-safe day arithmetic
# ============================================================
# US Eastern: spring forward Mar 8, 2026; fall back Nov 1, 2026.
# We use Julian Day Numbers for _days_diff, never seconds — so DST cannot corrupt results.

subtest 'DST — interval across spring-forward (Mar 8, 2026)' => sub {
    # created Mar 7, interval=7 → due Mar 14 (crosses DST boundary)
    my $t = task(class => 'interval', interval_days => 7,
                 created_at => '2026-03-07T00:00:00Z');
    is status($t, dt(2026,3,14)), 'due',     'interval 7d across spring-forward: due Mar 14';
    is status($t, dt(2026,3,13)), 'upcoming','Mar 13: due tomorrow';
    is status($t, dt(2026,3,15)), 'overdue', 'Mar 15: missed';
};

subtest 'DST — every_n_period across fall-back (Nov 1, 2026)' => sub {
    # every 1 week from Oct 25 → Nov 1 (DST fall-back day), then Nov 8
    my $t = task(class => 'every_n_period', interval_n => 1, period_unit => 'week',
                 anchor_date => '2026-10-25');
    is status($t, dt(2026,11,1)),                               'due',     'Nov 1 occurrence on fall-back day';
    is status($t, dt(2026,10,31), last_completed_dt => dt(2026,10,25)),
                                                                'upcoming', 'Oct 31: Nov 1 is 1 day out';
    is status($t, dt(2026,11,2)),                               'overdue',  'Nov 2: Nov 1 missed';
};

subtest 'DST — interval across fall-back (Nov 1, 2026)' => sub {
    # created Oct 28, interval=7 → due Nov 4
    my $t = task(class => 'interval', interval_days => 7,
                 created_at => '2026-10-28T00:00:00Z');
    is status($t, dt(2026,11,4)), 'due',    'interval 7d across fall-back: due Nov 4';
    is status($t, dt(2026,11,3)), 'upcoming','Nov 3: due tomorrow';
};

# ============================================================
# Edge: unknown class
# ============================================================

subtest 'unknown class croaks' => sub {
    eval { status(task(class => 'bogus'), dt(2026,6,1)) };
    like $@, qr/unknown.*class/i, 'unknown class throws';
};

done_testing;