nuwiki/crates/nuwiki-lsp/tests/diary.rs

//! Diary feature tests:
//! - Date primitives, path conventions, nav helpers, IndexedPage diary
//!   classification.
//! - Frequency wiring (daily/weekly/monthly/yearly): per-frequency
//!   path/URI shape, index recognition, and `next_period` / `prev_period`
//!   navigation across mixed-frequency entries.

use std::path::PathBuf;

use nuwiki_core::date::{DiaryDate, DiaryFrequency, DiaryPeriod};
use nuwiki_core::syntax::vimwiki::VimwikiSyntax;
use nuwiki_core::syntax::SyntaxPlugin;
use nuwiki_lsp::config::WikiConfig;
use nuwiki_lsp::diary;
use nuwiki_lsp::index::{diary_period_for_uri, WorkspaceIndex};
use tower_lsp::lsp_types::Url;

fn parse(src: &str) -> nuwiki_core::ast::DocumentNode {
    VimwikiSyntax::new().parse(src)
}

fn wiki_cfg(root: &str) -> WikiConfig {
    let mut cfg = WikiConfig::from_root(PathBuf::from(root));
    cfg.diary_rel_path = "diary".into();
    cfg.diary_index = "diary".into();
    cfg
}

fn build_index_with_entries(root: &str, dates: &[&str]) -> WorkspaceIndex {
    let mut idx =
        WorkspaceIndex::new(Some(PathBuf::from(root))).with_diary_rel_path(Some("diary".into()));
    for d in dates {
        let path = format!("{root}/diary/{d}.wiki");
        let uri = Url::from_file_path(&path).unwrap();
        idx.upsert(uri, &parse("= entry =\n"));
    }
    idx
}

// ===== DiaryDate parser =====

#[test]
fn parse_accepts_canonical_iso8601() {
    let d = DiaryDate::parse("2026-05-11").unwrap();
    assert_eq!(d.year, 2026);
    assert_eq!(d.month, 5);
    assert_eq!(d.day, 11);
}

#[test]
fn parse_rejects_missing_zero_padding() {
    assert!(DiaryDate::parse("2026-5-11").is_none());
    assert!(DiaryDate::parse("2026-05-1").is_none());
}

#[test]
fn parse_rejects_alternate_separators() {
    assert!(DiaryDate::parse("2026/05/11").is_none());
    assert!(DiaryDate::parse("2026.05.11").is_none());
}

#[test]
fn parse_rejects_extra_whitespace() {
    assert!(DiaryDate::parse(" 2026-05-11").is_none());
    assert!(DiaryDate::parse("2026-05-11 ").is_none());
}

#[test]
fn parse_rejects_invalid_calendar_dates() {
    assert!(DiaryDate::parse("2026-13-01").is_none(), "month 13");
    assert!(DiaryDate::parse("2026-02-30").is_none(), "feb 30");
    assert!(DiaryDate::parse("2026-04-31").is_none(), "april 31");
    assert!(DiaryDate::parse("2026-00-10").is_none(), "month 0");
    assert!(DiaryDate::parse("2026-05-00").is_none(), "day 0");
}

#[test]
fn parse_accepts_leap_day_in_leap_year() {
    assert!(DiaryDate::parse("2024-02-29").is_some(), "2024 is leap");
    assert!(DiaryDate::parse("2023-02-29").is_none(), "2023 not leap");
    assert!(DiaryDate::parse("2000-02-29").is_some(), "div by 400");
    assert!(
        DiaryDate::parse("1900-02-29").is_none(),
        "div by 100 not 400"
    );
}

#[test]
fn format_round_trip() {
    let d = DiaryDate::from_ymd(2026, 5, 11).unwrap();
    assert_eq!(d.format(), "2026-05-11");
    assert_eq!(DiaryDate::parse(&d.format()), Some(d));
}

// ===== Date arithmetic =====

#[test]
fn next_day_wraps_month_boundary() {
    let last_of_jan = DiaryDate::from_ymd(2026, 1, 31).unwrap();
    assert_eq!(
        last_of_jan.next_day(),
        DiaryDate::from_ymd(2026, 2, 1).unwrap()
    );
}

#[test]
fn next_day_wraps_year_boundary() {
    let nye = DiaryDate::from_ymd(2025, 12, 31).unwrap();
    assert_eq!(nye.next_day(), DiaryDate::from_ymd(2026, 1, 1).unwrap());
}

#[test]
fn prev_day_walks_back_across_month() {
    let first_of_mar = DiaryDate::from_ymd(2026, 3, 1).unwrap();
    assert_eq!(
        first_of_mar.prev_day(),
        DiaryDate::from_ymd(2026, 2, 28).unwrap()
    );
}

#[test]
fn prev_day_walks_back_across_leap() {
    let first_of_mar = DiaryDate::from_ymd(2024, 3, 1).unwrap();
    assert_eq!(
        first_of_mar.prev_day(),
        DiaryDate::from_ymd(2024, 2, 29).unwrap()
    );
}

#[test]
fn ordering_is_chronological() {
    let a = DiaryDate::from_ymd(2026, 1, 1).unwrap();
    let b = DiaryDate::from_ymd(2026, 1, 2).unwrap();
    let c = DiaryDate::from_ymd(2026, 2, 1).unwrap();
    let d = DiaryDate::from_ymd(2027, 1, 1).unwrap();
    assert!(a < b);
    assert!(b < c);
    assert!(c < d);
}

#[test]
fn today_utc_is_a_real_calendar_date() {
    let t = DiaryDate::today_utc();
    assert!(t.year >= 2020 && t.year <= 2100);
    assert!((1..=12).contains(&t.month));
    assert!((1..=31).contains(&t.day));
}

// ===== WikiConfig diary paths =====

#[test]
fn diary_dir_joins_root_and_rel_path() {
    let cfg = wiki_cfg("/tmp/wiki");
    assert_eq!(cfg.diary_dir(), PathBuf::from("/tmp/wiki/diary"));
}

#[test]
fn diary_index_path_uses_diary_index_filename_and_extension() {
    let cfg = wiki_cfg("/tmp/wiki");
    assert_eq!(
        cfg.diary_index_path(),
        PathBuf::from("/tmp/wiki/diary/diary.wiki")
    );
}

#[test]
fn diary_path_for_uses_iso_date_as_stem() {
    let cfg = wiki_cfg("/tmp/wiki");
    let date = DiaryDate::from_ymd(2026, 5, 11).unwrap();
    assert_eq!(
        cfg.diary_path_for(&date),
        PathBuf::from("/tmp/wiki/diary/2026-05-11.wiki")
    );
}

#[test]
fn diary_uri_for_date_is_file_url() {
    let cfg = wiki_cfg("/tmp/wiki");
    let date = DiaryDate::from_ymd(2026, 5, 11).unwrap();
    let uri = diary::uri_for_date(&cfg, &date).unwrap();
    assert!(uri.as_str().ends_with("/diary/2026-05-11.wiki"));
}

#[test]
fn diary_index_uri_resolves() {
    let cfg = wiki_cfg("/tmp/wiki");
    let uri = diary::index_uri(&cfg).unwrap();
    assert!(uri.as_str().ends_with("/diary/diary.wiki"));
}

// ===== Index integration: diary_date on IndexedPage =====

#[test]
fn upsert_marks_diary_entries() {
    let root = "/tmp/diary1";
    let idx = build_index_with_entries(root, &["2026-05-11"]);
    let uri = Url::from_file_path(format!("{root}/diary/2026-05-11.wiki")).unwrap();
    let page = idx.page(&uri).expect("page");
    let date = page.diary_date.expect("diary_date");
    assert_eq!(date.format(), "2026-05-11");
}

#[test]
fn upsert_does_not_mark_non_diary_files() {
    let mut idx = WorkspaceIndex::new(Some(PathBuf::from("/tmp/diary2")))
        .with_diary_rel_path(Some("diary".into()));
    let uri = Url::from_file_path("/tmp/diary2/Home.wiki").unwrap();
    idx.upsert(uri.clone(), &parse("= Home =\n"));
    assert!(idx.page(&uri).unwrap().diary_date.is_none());
}

#[test]
fn upsert_does_not_mark_dates_outside_diary_subdir() {
    // A file at root named like a date but not under diary/ → not a
    // diary entry.
    let mut idx = WorkspaceIndex::new(Some(PathBuf::from("/tmp/diary3")))
        .with_diary_rel_path(Some("diary".into()));
    let uri = Url::from_file_path("/tmp/diary3/2026-05-11.wiki").unwrap();
    idx.upsert(uri.clone(), &parse("= note =\n"));
    assert!(idx.page(&uri).unwrap().diary_date.is_none());
}

// ===== Diary listing + navigation =====

#[test]
fn list_entries_returns_sorted_ascending() {
    let idx = build_index_with_entries("/tmp/diary4", &["2026-05-11", "2026-04-30", "2026-05-12"]);
    let entries = diary::list_entries(&idx);
    let dates: Vec<String> = entries.iter().map(|e| e.date.format()).collect();
    assert_eq!(dates, vec!["2026-04-30", "2026-05-11", "2026-05-12"]);
}

#[test]
fn list_entries_filtered_by_year_and_month() {
    let idx = build_index_with_entries(
        "/tmp/diary5",
        &["2025-12-31", "2026-01-01", "2026-05-11", "2026-05-12"],
    );
    let may = diary::list_entries_filtered(&idx, Some(2026), Some(5));
    assert_eq!(may.len(), 2);
    let y_only = diary::list_entries_filtered(&idx, Some(2026), None);
    assert_eq!(y_only.len(), 3);
}

#[test]
fn next_entry_finds_strictly_greater() {
    let idx = build_index_with_entries("/tmp/diary6", &["2026-05-10", "2026-05-12", "2026-05-15"]);
    let from = DiaryDate::from_ymd(2026, 5, 11).unwrap();
    let next = diary::next_entry(&idx, &from).unwrap();
    assert_eq!(next.date.format(), "2026-05-12");
}

#[test]
fn next_entry_none_when_no_future_entries() {
    let idx = build_index_with_entries("/tmp/diary7", &["2026-05-10"]);
    let from = DiaryDate::from_ymd(2026, 5, 11).unwrap();
    assert!(diary::next_entry(&idx, &from).is_none());
}

#[test]
fn prev_entry_finds_strictly_lesser() {
    let idx = build_index_with_entries("/tmp/diary8", &["2026-05-10", "2026-05-12", "2026-05-15"]);
    let from = DiaryDate::from_ymd(2026, 5, 13).unwrap();
    let prev = diary::prev_entry(&idx, &from).unwrap();
    assert_eq!(prev.date.format(), "2026-05-12");
}

// ===== Index body generation =====

#[test]
fn build_index_body_is_newest_first_grouped_by_year_month() {
    let idx = build_index_with_entries(
        "/tmp/diary9",
        &["2025-12-31", "2026-05-11", "2026-05-12", "2026-04-30"],
    );
    let entries = diary::list_entries(&idx);
    let body = diary::build_index_body(
        &entries,
        "diary",
        "Diary",
        diary::DiarySort::Desc,
        1,
        &[],
        0,
    );
    let lines: Vec<&str> = body.lines().collect();
    assert_eq!(lines[0], "= Diary =");
    // First date in output should be the latest: 2026-05-12
    let earliest_2026_pos = body.find("2026-05-12").unwrap();
    let latest_2025_pos = body.find("2025-12-31").unwrap();
    assert!(earliest_2026_pos < latest_2025_pos, "newer entries first");
    // Year headings appear
    assert!(body.contains("== 2026 =="));
    assert!(body.contains("== 2025 =="));
    // Month headings appear
    assert!(body.contains("=== May ==="));
    assert!(body.contains("=== December ==="));
    assert!(body.contains("=== April ==="));
}

#[test]
fn build_index_body_empty_when_no_entries() {
    let body = diary::build_index_body(&[], "diary", "Diary", diary::DiarySort::Desc, 1, &[], 0);
    assert_eq!(body, "= Diary =\n");
}

#[test]
fn build_index_body_ascending_sort_lists_oldest_first() {
    let idx = build_index_with_entries("/tmp/diarySort", &["2026-05-11", "2026-05-12"]);
    let entries = diary::list_entries(&idx);
    let body =
        diary::build_index_body(&entries, "diary", "Diary", diary::DiarySort::Asc, 1, &[], 0);
    let older = body.find("2026-05-11").unwrap();
    let newer = body.find("2026-05-12").unwrap();
    assert!(older < newer, "ascending sort lists oldest first");
}

#[test]
fn build_index_body_caption_level_shifts_all_headings() {
    let idx = build_index_with_entries("/tmp/diaryCap", &["2026-05-11"]);
    let entries = diary::list_entries(&idx);
    let body = diary::build_index_body(
        &entries,
        "diary",
        "Diary",
        diary::DiarySort::Desc,
        2,
        &[],
        0,
    );
    assert!(body.contains("== Diary =="), "caption at level 2");
    assert!(
        body.contains("=== 2026 ==="),
        "year nests one below caption"
    );
    assert!(
        body.contains("==== May ===="),
        "month nests two below caption"
    );
}

#[test]
fn build_index_body_clamps_caption_level_to_six() {
    let idx = build_index_with_entries("/tmp/diaryClamp", &["2026-05-11"]);
    let entries = diary::list_entries(&idx);
    // caption_level 6 → year/month would be 7/8 but clamp to 6.
    let body = diary::build_index_body(
        &entries,
        "diary",
        "Diary",
        diary::DiarySort::Desc,
        6,
        &[],
        0,
    );
    assert!(body.contains("====== Diary ======"));
    assert!(!body.contains("======="), "no heading exceeds level 6");
}

#[test]
fn build_index_body_uses_custom_diary_months() {
    let idx = build_index_with_entries("/tmp/diaryMonths", &["2026-05-11", "2026-12-01"]);
    let entries = diary::list_entries(&idx);
    // A localized month table (Portuguese) replaces the English labels.
    let months: Vec<String> = [
        "Janeiro",
        "Fevereiro",
        "Março",
        "Abril",
        "Maio",
        "Junho",
        "Julho",
        "Agosto",
        "Setembro",
        "Outubro",
        "Novembro",
        "Dezembro",
    ]
    .iter()
    .map(|s| s.to_string())
    .collect();
    let body = diary::build_index_body(
        &entries,
        "diary",
        "Diary",
        diary::DiarySort::Desc,
        1,
        &months,
        0,
    );
    assert!(body.contains("=== Maio ==="), "May → Maio: {body}");
    assert!(
        body.contains("=== Dezembro ==="),
        "December → Dezembro: {body}"
    );
    assert!(!body.contains("May"), "English label leaked: {body}");
}

#[test]
fn build_index_body_falls_back_per_missing_month_slot() {
    let idx = build_index_with_entries("/tmp/diaryShort", &["2026-05-11"]);
    let entries = diary::list_entries(&idx);
    // A too-short table only covers Jan–Mar; May falls back to English.
    let months: Vec<String> = ["Jan", "Feb", "Mar"]
        .iter()
        .map(|s| s.to_string())
        .collect();
    let body = diary::build_index_body(
        &entries,
        "diary",
        "Diary",
        diary::DiarySort::Desc,
        1,
        &months,
        0,
    );
    assert!(
        body.contains("=== May ==="),
        "missing slot → English: {body}"
    );
}

#[test]
fn build_index_body_clamps_negative_caption_level_to_zero() {
    let idx = build_index_with_entries("/tmp/diaryNeg", &["2026-05-11"]);
    let entries = diary::list_entries(&idx);
    // vimwiki allows diary_caption_level = -1; nuwiki clamps it to 0 (same as
    // a caption_level of 0: caption h1, year h1, month h2).
    let body = diary::build_index_body(
        &entries,
        "diary",
        "Diary",
        diary::DiarySort::Desc,
        -1,
        &[],
        0,
    );
    assert!(body.contains("= Diary ="), "caption at level 1: {body}");
    assert!(body.contains("= 2026 ="), "year at level 1: {body}");
    assert!(body.contains("== May =="), "month at level 2: {body}");
}

#[test]
fn render_index_body_round_trip() {
    let cfg = wiki_cfg("/tmp/diaryA");
    let idx = build_index_with_entries("/tmp/diaryA", &["2026-05-11"]);
    let body = diary::render_index_body(&cfg, &idx);
    assert!(body.contains("= Diary ="));
    assert!(body.contains("[[diary/2026-05-11]]"));
}

#[test]
fn render_index_body_honours_custom_header_sort_and_caption() {
    let mut cfg = wiki_cfg("/tmp/diaryCustom");
    cfg.diary_header = "Journal".into();
    cfg.diary_sort = "asc".into();
    cfg.diary_caption_level = 2;
    let idx = build_index_with_entries("/tmp/diaryCustom", &["2026-05-11", "2026-05-12"]);
    let body = diary::render_index_body(&cfg, &idx);
    assert!(
        body.contains("== Journal =="),
        "custom header at caption level 2"
    );
    let older = body.find("2026-05-11").unwrap();
    let newer = body.find("2026-05-12").unwrap();
    assert!(older < newer, "asc sort honoured");
}

// ===== is_in_diary =====

#[test]
fn is_in_diary_recognises_subdir_paths() {
    let cfg = wiki_cfg("/tmp/wiki");
    assert!(diary::is_in_diary(
        &cfg,
        &PathBuf::from("/tmp/wiki/diary/2026-05-11.wiki")
    ));
    assert!(!diary::is_in_diary(
        &cfg,
        &PathBuf::from("/tmp/wiki/Home.wiki")
    ));
}

// ===== Serde =====

#[test]
fn diary_entry_serializes_to_date_string_and_uri() {
    let uri = Url::parse("file:///tmp/wiki/diary/2026-05-11.wiki").unwrap();
    let entry = diary::DiaryEntry {
        date: DiaryDate::from_ymd(2026, 5, 11).unwrap(),
        uri,
    };
    let v = serde_json::to_value(&entry).unwrap();
    assert_eq!(v["date"], "2026-05-11");
    assert!(v["uri"].as_str().unwrap().contains("2026-05-11.wiki"));
}

// ===== COMMANDS list completeness =====

#[test]
fn commands_list_includes_diary_entries() {
    let names: Vec<&str> = nuwiki_lsp::commands::COMMANDS.to_vec();
    for name in [
        "nuwiki.diary.openToday",
        "nuwiki.diary.openYesterday",
        "nuwiki.diary.openTomorrow",
        "nuwiki.diary.openIndex",
        "nuwiki.diary.generateIndex",
        "nuwiki.diary.next",
        "nuwiki.diary.prev",
        "nuwiki.diary.listEntries",
        "nuwiki.diary.openForDate",
    ] {
        assert!(names.contains(&name), "missing: {name}");
    }
}

// ===== Config wire format =====

#[test]
fn wiki_config_defaults_match_vimwiki() {
    let cfg = WikiConfig::empty();
    assert_eq!(cfg.diary_rel_path, "diary");
    assert_eq!(cfg.diary_index, "diary");
}

#[test]
fn wiki_config_from_root_uses_default_diary_paths() {
    let cfg = WikiConfig::from_root(PathBuf::from("/tmp/x"));
    assert_eq!(cfg.diary_rel_path, "diary");
}

#[test]
fn config_from_json_accepts_custom_diary_paths() {
    use nuwiki_lsp::config::config_from_json;
    let cfg = config_from_json(serde_json::json!({
        "wikis": [
            { "root": "/tmp/p", "diary_rel_path": "journal", "diary_index": "index" },
        ],
    }));
    assert_eq!(cfg.wikis[0].diary_rel_path, "journal");
    assert_eq!(cfg.wikis[0].diary_index, "index");
}

// ===== Frequency wiring (daily / weekly / monthly / yearly) =====

fn cfg(root: &str, frequency: &str) -> WikiConfig {
    let mut c = WikiConfig::from_root(PathBuf::from(root));
    c.diary_rel_path = "diary".into();
    c.diary_frequency = frequency.into();
    c
}

#[test]
fn frequency_helper_picks_up_config_value() {
    assert_eq!(cfg("/tmp", "daily").frequency(), DiaryFrequency::Daily);
    assert_eq!(cfg("/tmp", "weekly").frequency(), DiaryFrequency::Weekly);
    assert_eq!(cfg("/tmp", "monthly").frequency(), DiaryFrequency::Monthly);
    assert_eq!(cfg("/tmp", "yearly").frequency(), DiaryFrequency::Yearly);
}

#[test]
fn diary_path_for_period_picks_right_stem_per_frequency() {
    let c = cfg("/wiki", "daily");
    let day = DiaryPeriod::Day(DiaryDate::from_ymd(2026, 5, 12).unwrap());
    let wk = DiaryPeriod::Week {
        iso_year: 2026,
        iso_week: 19,
    };
    let mo = DiaryPeriod::Month {
        year: 2026,
        month: 5,
    };
    let yr = DiaryPeriod::Year { year: 2026 };
    assert_eq!(
        c.diary_path_for_period(&day),
        PathBuf::from("/wiki/diary/2026-05-12.wiki")
    );
    assert_eq!(
        c.diary_path_for_period(&wk),
        PathBuf::from("/wiki/diary/2026-W19.wiki")
    );
    assert_eq!(
        c.diary_path_for_period(&mo),
        PathBuf::from("/wiki/diary/2026-05.wiki")
    );
    assert_eq!(
        c.diary_path_for_period(&yr),
        PathBuf::from("/wiki/diary/2026.wiki")
    );
}

#[test]
fn uri_for_period_produces_file_url_per_frequency() {
    let c = cfg("/wiki", "weekly");
    let wk = DiaryPeriod::Week {
        iso_year: 2026,
        iso_week: 19,
    };
    let u = diary::uri_for_period(&c, &wk).unwrap();
    assert!(
        u.as_str().ends_with("/wiki/diary/2026-W19.wiki"),
        "got: {u}"
    );
}

fn make_index_with(entries: &[&str]) -> WorkspaceIndex {
    let root = PathBuf::from("/wiki");
    let mut idx = WorkspaceIndex::new(Some(root.clone())).with_diary_rel_path(Some("diary".into()));
    for stem in entries {
        let path = format!("/wiki/diary/{stem}.wiki");
        let uri = Url::from_file_path(&path).unwrap();
        let ast = VimwikiSyntax::new().parse("= entry =\n");
        idx.upsert(uri, &ast);
    }
    idx
}

#[test]
fn index_recognises_all_four_frequency_stems() {
    let idx = make_index_with(&["2026-05-12", "2026-W19", "2026-05", "2026"]);
    for (stem, expected) in [
        (
            "2026-05-12",
            DiaryPeriod::Day(DiaryDate::from_ymd(2026, 5, 12).unwrap()),
        ),
        (
            "2026-W19",
            DiaryPeriod::Week {
                iso_year: 2026,
                iso_week: 19,
            },
        ),
        (
            "2026-05",
            DiaryPeriod::Month {
                year: 2026,
                month: 5,
            },
        ),
        ("2026", DiaryPeriod::Year { year: 2026 }),
    ] {
        let uri = Url::from_file_path(format!("/wiki/diary/{stem}.wiki")).unwrap();
        let page = idx.page(&uri).expect(stem);
        assert_eq!(
            page.diary_period,
            Some(expected),
            "stem {stem} should index as {expected:?}"
        );
    }
}

#[test]
fn index_only_sets_diary_date_for_daily_entries() {
    let idx = make_index_with(&["2026-05-12", "2026-W19"]);
    let daily = Url::from_file_path("/wiki/diary/2026-05-12.wiki").unwrap();
    let weekly = Url::from_file_path("/wiki/diary/2026-W19.wiki").unwrap();
    assert!(idx.page(&daily).unwrap().diary_date.is_some());
    assert!(idx.page(&weekly).unwrap().diary_date.is_none());
    assert!(idx.page(&weekly).unwrap().diary_period.is_some());
}

#[test]
fn diary_period_for_uri_rejects_paths_outside_diary_dir() {
    // Non-diary path with a date-looking stem — should NOT count.
    let uri = Url::from_file_path("/wiki/notes/2026-05-12.wiki").unwrap();
    let root = PathBuf::from("/wiki");
    assert!(diary_period_for_uri(&uri, Some(&root), Some("diary")).is_none());
}

#[test]
fn next_prev_period_navigate_at_the_same_frequency() {
    // Mix entries at different frequencies. Navigation should stay
    // within the same flavour as the pivot.
    let idx = make_index_with(&[
        "2026-W18",
        "2026-W19",
        "2026-W20", // weekly
        "2026-04",
        "2026-05",
        "2026-06", // monthly
        "2026-05-10",
        "2026-05-12", // daily
    ]);
    let pivot_w = DiaryPeriod::Week {
        iso_year: 2026,
        iso_week: 19,
    };
    let next_w = diary::next_period(&idx, &pivot_w).unwrap();
    assert_eq!(
        next_w.period,
        DiaryPeriod::Week {
            iso_year: 2026,
            iso_week: 20
        }
    );
    let prev_w = diary::prev_period(&idx, &pivot_w).unwrap();
    assert_eq!(
        prev_w.period,
        DiaryPeriod::Week {
            iso_year: 2026,
            iso_week: 18
        }
    );

    let pivot_m = DiaryPeriod::Month {
        year: 2026,
        month: 5,
    };
    let next_m = diary::next_period(&idx, &pivot_m).unwrap();
    assert_eq!(
        next_m.period,
        DiaryPeriod::Month {
            year: 2026,
            month: 6
        }
    );
    let prev_m = diary::prev_period(&idx, &pivot_m).unwrap();
    assert_eq!(
        prev_m.period,
        DiaryPeriod::Month {
            year: 2026,
            month: 4
        }
    );
}

#[test]
fn next_prev_period_returns_none_past_the_edge() {
    let idx = make_index_with(&["2026-W19"]);
    let only = DiaryPeriod::Week {
        iso_year: 2026,
        iso_week: 19,
    };
    assert!(diary::next_period(&idx, &only).is_none());
    assert!(diary::prev_period(&idx, &only).is_none());
}

#[test]
fn diary_period_for_uri_handles_each_frequency_under_diary_dir() {
    let root = PathBuf::from("/wiki");
    for (stem, expected) in [
        (
            "2026-05-12",
            DiaryPeriod::Day(DiaryDate::from_ymd(2026, 5, 12).unwrap()),
        ),
        (
            "2026-W19",
            DiaryPeriod::Week {
                iso_year: 2026,
                iso_week: 19,
            },
        ),
        (
            "2026-05",
            DiaryPeriod::Month {
                year: 2026,
                month: 5,
            },
        ),
        ("2026", DiaryPeriod::Year { year: 2026 }),
    ] {
        let uri = Url::from_file_path(format!("/wiki/diary/{stem}.wiki")).unwrap();
        let got = diary_period_for_uri(&uri, Some(&root), Some("diary"));
        assert_eq!(got, Some(expected), "stem {stem}");
    }
}