print-atlas.test.ts

import { describe, it } from "node:test";
import assert from "node:assert/strict";
import type { Feature, FeatureCollection } from "geojson";
import {
  atlasEntryName,
  atlasViewportFrame,
  buildAtlasPages,
  buildLineAtlasPages,
  hasLineGeometry,
  MAX_LINE_ATLAS_PAGES,
  expandBounds,
  geometryBounds,
  listAtlasFields,
  parseAtlasFilter,
  stripAtlasTokens,
  substituteAtlasTokens,
  type AtlasTokenContext,
} from "../apps/geolibre-desktop/src/lib/print-atlas";

function ctx(overrides: Partial<AtlasTokenContext> = {}): AtlasTokenContext {
  return {
    name: "Springfield",
    pageNumber: 3,
    total: 28,
    properties: { STATE: "IL", POP: 116250 },
    ...overrides,
  };
}

function feature(properties: Record<string, unknown>, coords: [number, number] = [0, 0]): Feature {
  return {
    type: "Feature",
    properties,
    geometry: { type: "Point", coordinates: coords },
  };
}

function collection(features: Feature[]): FeatureCollection {
  return { type: "FeatureCollection", features };
}

describe("substituteAtlasTokens", () => {
  it("replaces the built-in tokens", () => {
    assert.equal(
      substituteAtlasTokens("{atlas.name} - page {atlas.pagenumber} of {atlas.total}", ctx()),
      "Springfield - page 3 of 28",
    );
  });

  it("replaces attribute tokens and blanks unknown or null fields", () => {
    assert.equal(substituteAtlasTokens("{atlas.attr:STATE}/{atlas.attr:MISSING}", ctx()), "IL/");
    assert.equal(
      substituteAtlasTokens("[{atlas.attr:NIL}]", ctx({ properties: { NIL: null } })),
      "[]",
    );
  });

  it("passes token-free text through unchanged", () => {
    assert.equal(substituteAtlasTokens("Plain title", ctx()), "Plain title");
    assert.equal(substituteAtlasTokens("", ctx()), "");
  });

  it("repeats a token every time it appears", () => {
    assert.equal(
      substituteAtlasTokens("{atlas.name} {atlas.name}", ctx()),
      "Springfield Springfield",
    );
  });
});

describe("stripAtlasTokens", () => {
  it("removes tokens and collapses leftover whitespace", () => {
    assert.equal(stripAtlasTokens("River atlas {atlas.name} {atlas.attr:SEG}"), "River atlas");
    assert.equal(stripAtlasTokens("{atlas.pagenumber}"), "");
  });
});

describe("geometryBounds", () => {
  it("computes bounds for points, lines, and polygons", () => {
    assert.deepEqual(geometryBounds({ type: "Point", coordinates: [10, 20] }), [10, 20, 10, 20]);
    assert.deepEqual(
      geometryBounds({
        type: "LineString",
        coordinates: [
          [-3, 5],
          [7, -2],
        ],
      }),
      [-3, -2, 7, 5],
    );
    assert.deepEqual(
      geometryBounds({
        type: "MultiPolygon",
        coordinates: [
          [
            [
              [0, 0],
              [4, 0],
              [4, 3],
              [0, 0],
            ],
          ],
          [
            [
              [-1, -1],
              [1, -1],
              [1, 1],
              [-1, -1],
            ],
          ],
        ],
      }),
      [-1, -1, 4, 3],
    );
  });

  it("unwraps antimeridian-crossing features to a narrow box", () => {
    // Fiji-like: vertices on both sides of 180°. The raw min/max box would
    // span the far side of the globe; the unwrapped box is ~2° wide with an
    // east longitude past 180 (which MapLibre's fitBounds understands).
    assert.deepEqual(
      geometryBounds({
        type: "LineString",
        coordinates: [
          [179, -17],
          [-179, -16],
        ],
      }),
      [179, -17, 181, -16],
    );
    // A hemisphere-wide feature that does not cross ±180° keeps the raw box.
    assert.deepEqual(
      geometryBounds({
        type: "LineString",
        coordinates: [
          [-90, 0],
          [90, 10],
        ],
      }),
      [-90, 0, 90, 10],
    );
  });

  it("handles GeometryCollections and rejects empty geometries", () => {
    assert.deepEqual(
      geometryBounds({
        type: "GeometryCollection",
        geometries: [
          { type: "Point", coordinates: [1, 1] },
          { type: "Point", coordinates: [5, -5] },
        ],
      }),
      [1, -5, 5, 1],
    );
    assert.equal(geometryBounds(null), null);
    assert.equal(geometryBounds({ type: "MultiPoint", coordinates: [] }), null);
  });
});

describe("expandBounds", () => {
  it("expands each side by the margin percentage of its span", () => {
    assert.deepEqual(expandBounds([0, 0, 10, 20], 10), [-1, -2, 11, 22]);
  });

  it("pads degenerate (point) bounds to a minimum span", () => {
    const [w, s, e, n] = expandBounds([5, 5, 5, 5], 10, 0.01);
    assert.ok(e - w >= 0.01 - 1e-12);
    assert.ok(n - s >= 0.01 - 1e-12);
    assert.ok(Math.abs((w + e) / 2 - 5) < 1e-12);
  });

  it("clamps latitudes to the Web Mercator range", () => {
    const [, s, , n] = expandBounds([-180, -84, 180, 84], 50);
    assert.equal(s, -85);
    assert.equal(n, 85);
  });

  it("keeps polar point bounds valid (no inverted box)", () => {
    const [w, s, e, n] = expandBounds([0, 90, 0, 90], 10);
    assert.ok(n > s);
    assert.ok(e > w);
    assert.ok(s >= -85 && n <= 85);
    assert.ok(n - s >= 0.005 - 1e-12);
  });
});

describe("atlasViewportFrame", () => {
  it("adds vertical padding when the print frame is wider than the live map", () => {
    const frame = atlasViewportFrame(1200, 900, 2);
    assert.deepEqual(frame.padding, {
      top: 150,
      bottom: 150,
      left: 0,
      right: 0,
    });
    assert.deepEqual(frame.crop, {
      top: 150,
      bottom: 750,
      left: 0,
      right: 1200,
    });
  });

  it("adds horizontal padding when the print frame is narrower than the live map", () => {
    const frame = atlasViewportFrame(1200, 600, 1);
    assert.deepEqual(frame.padding, {
      top: 0,
      bottom: 0,
      left: 300,
      right: 300,
    });
    assert.deepEqual(frame.crop, {
      top: 0,
      bottom: 600,
      left: 300,
      right: 900,
    });
  });

  it("keeps the full viewport for matching or invalid aspect ratios", () => {
    assert.deepEqual(atlasViewportFrame(1200, 600, 2).padding, {
      top: 0,
      bottom: 0,
      left: 0,
      right: 0,
    });
    assert.deepEqual(atlasViewportFrame(1200, 600, 0).crop, {
      top: 0,
      bottom: 600,
      left: 0,
      right: 1200,
    });
  });
});

describe("listAtlasFields", () => {
  it("unions property keys in first-seen order", () => {
    const fields = listAtlasFields([feature({ b: 1, a: 2 }), feature({ c: 3, a: 4 })]);
    assert.deepEqual(fields, ["b", "a", "c"]);
  });
});

describe("parseAtlasFilter", () => {
  it("matches everything for a blank expression", () => {
    const p = parseAtlasFilter("   ");
    assert.ok(p);
    assert.equal(p?.({}), true);
  });

  it("compares numerically when both sides are numbers", () => {
    const p = parseAtlasFilter("POP > 100000");
    assert.ok(p);
    assert.equal(p?.({ POP: 116250 }), true);
    assert.equal(p?.({ POP: "99999" }), false);
    assert.equal(p?.({ POP: null }), false);
  });

  it("supports equality on strings, quoted or bare", () => {
    const eq = parseAtlasFilter('ST = "CA"');
    assert.equal(eq?.({ ST: "CA" }), true);
    assert.equal(eq?.({ ST: "OR" }), false);
    const bare = parseAtlasFilter("ST != CA");
    assert.equal(bare?.({ ST: "OR" }), true);
  });

  it("lets != match features missing the field entirely", () => {
    const ne = parseAtlasFilter('STATUS != "archived"');
    assert.equal(ne?.({}), true);
    assert.equal(ne?.({ STATUS: null }), true);
    assert.equal(ne?.({ STATUS: "active" }), true);
    assert.equal(ne?.({ STATUS: "archived" }), false);
    // Every other operator still cannot be satisfied by a missing field.
    assert.equal(parseAtlasFilter('STATUS = "x"')?.({}), false);
    assert.equal(parseAtlasFilter("STATUS contains x")?.({}), false);
  });

  it("treats == as an alias for =", () => {
    const p = parseAtlasFilter('ST == "CA"');
    assert.equal(p?.({ ST: "CA" }), true);
    assert.equal(p?.({ ST: "OR" }), false);
  });

  it("does not split on 'and' inside quoted values", () => {
    const eq = parseAtlasFilter('NAME = "Sam and Max"');
    assert.equal(eq?.({ NAME: "Sam and Max" }), true);
    assert.equal(eq?.({ NAME: "Sam" }), false);
    const combined = parseAtlasFilter("NAME contains 'rock and roll' and POP > 5");
    assert.equal(combined?.({ NAME: "Rock and Roll Hall", POP: 10 }), true);
    assert.equal(combined?.({ NAME: "Rock and Roll Hall", POP: 1 }), false);
  });

  it("supports case-insensitive contains", () => {
    const p = parseAtlasFilter("NAME contains york");
    assert.equal(p?.({ NAME: "New York" }), true);
    assert.equal(p?.({ NAME: "Boston" }), false);
  });

  it("joins conditions with and", () => {
    const p = parseAtlasFilter('POP >= 1000 and ST = "CA"');
    assert.equal(p?.({ POP: 2000, ST: "CA" }), true);
    assert.equal(p?.({ POP: 2000, ST: "OR" }), false);
    assert.equal(p?.({ POP: 500, ST: "CA" }), false);
  });

  it("returns null for malformed expressions", () => {
    assert.equal(parseAtlasFilter("POP >"), null);
    assert.equal(parseAtlasFilter("just words"), null);
  });

  it("rejects ordering comparisons on non-numeric values", () => {
    const p = parseAtlasFilter("POP > 10");
    assert.equal(p?.({ POP: "many" }), false);
  });
});

describe("buildAtlasPages", () => {
  const features = [
    feature({ NAME: "B-ville", POP: 200 }, [1, 1]),
    feature({ NAME: "A-town", POP: 300 }, [2, 2]),
    feature({ NAME: "C-city", POP: 100 }, [3, 3]),
  ];

  it("creates one page per feature in source order by default", () => {
    const pages = buildAtlasPages(collection(features));
    assert.equal(pages.length, 3);
    assert.deepEqual(
      pages.map((p) => p.name),
      ["Feature 1", "Feature 2", "Feature 3"],
    );
    assert.deepEqual(
      pages.map((p) => p.index),
      [0, 1, 2],
    );
    assert.deepEqual(
      pages.map((p) => p.sourceIndex),
      [0, 1, 2],
    );
    assert.deepEqual(pages[0].bounds, [1, 1, 1, 1]);
  });

  it("names pages from the name field, falling back per feature", () => {
    const pages = buildAtlasPages(collection([...features, feature({ NAME: "" }, [4, 4])]), {
      nameField: "NAME",
    });
    assert.deepEqual(
      pages.map((p) => p.name),
      ["B-ville", "A-town", "C-city", "Feature 4"],
    );
  });

  it("sorts by field ascending and descending", () => {
    const asc = buildAtlasPages(collection(features), {
      nameField: "NAME",
      sortField: "POP",
    });
    assert.deepEqual(
      asc.map((p) => p.name),
      ["C-city", "B-ville", "A-town"],
    );
    const desc = buildAtlasPages(collection(features), {
      nameField: "NAME",
      sortField: "POP",
      sortDescending: true,
    });
    assert.deepEqual(
      desc.map((p) => p.name),
      ["A-town", "B-ville", "C-city"],
    );
    assert.deepEqual(
      desc.map((p) => p.index),
      [0, 1, 2],
    );
    // Source identity survives the reorder.
    assert.deepEqual(
      desc.map((p) => p.sourceIndex),
      [1, 0, 2],
    );
  });

  it("sorts missing values last in both directions", () => {
    const withMissing = collection([
      feature({ NAME: "x" }, [0, 0]),
      feature({ NAME: "y", POP: 1 }, [0, 0]),
    ]);
    for (const sortDescending of [false, true]) {
      const pages = buildAtlasPages(withMissing, {
        nameField: "NAME",
        sortField: "POP",
        sortDescending,
      });
      assert.equal(pages[pages.length - 1].name, "x");
    }
  });

  it("applies the filter and skips features without geometry", () => {
    const mixed = collection([
      ...features,
      {
        type: "Feature",
        properties: { NAME: "no-geom", POP: 9999 },
        geometry: null,
      } as unknown as Feature,
    ]);
    const pages = buildAtlasPages(mixed, {
      nameField: "NAME",
      filter: parseAtlasFilter("POP >= 200"),
    });
    assert.deepEqual(
      pages.map((p) => p.name),
      ["B-ville", "A-town"],
    );
  });
});

describe("atlasEntryName", () => {
  it("substitutes tokens and sanitizes the result", () => {
    assert.equal(atlasEntryName("{atlas.pagenumber}-{atlas.name}", ctx()), "3-Springfield");
    assert.equal(atlasEntryName("{atlas.attr:STATE} / {atlas.name}", ctx()), "IL-Springfield");
  });

  it("falls back to the page number when the pattern collapses", () => {
    assert.equal(atlasEntryName("{atlas.attr:MISSING}", ctx()), "3");
    assert.equal(atlasEntryName("", ctx()), "3-Springfield");
  });
});

describe("buildLineAtlasPages", () => {
  // 1 degree of longitude along the equator is ~111.195 km, so this line is a
  // convenient known length for segment math.
  const equatorLine: Feature = {
    type: "Feature",
    properties: { river: "Blackfeather", region: "north" },
    geometry: {
      type: "LineString",
      coordinates: [
        [0, 0],
        [0.5, 0],
        [1, 0],
      ],
    },
  };

  it("tiles a line into fixed-length stretches with a trailing remainder", () => {
    const pages = buildLineAtlasPages(collection([equatorLine]), {
      segmentKm: 25,
      nameField: "river",
    });
    assert.equal(pages.length, 5);
    assert.deepEqual(
      pages.map((p) => [p.properties.km_start, p.properties.km_end]),
      [
        [0, 25],
        [25, 50],
        [50, 75],
        [75, 100],
        [100, 111.2],
      ],
    );
    assert.equal(pages[0].name, "Blackfeather km 0-25");
    assert.equal(pages[4].name, "Blackfeather km 100-111.2");
    assert.deepEqual(
      pages.map((p) => p.index),
      [0, 1, 2, 3, 4],
    );
    // sourceIndex keeps the *feature's* identity: all stretches of one line.
    assert.deepEqual(
      pages.map((p) => p.sourceIndex),
      [0, 0, 0, 0, 0],
    );
    // Segment metadata and inherited feature attributes.
    assert.equal(pages[2].properties.segment, 3);
    assert.equal(pages[2].properties.segments, 5);
    assert.equal(pages[2].properties.region, "north");
  });

  it("produces contiguous, ordered, non-degenerate bounds", () => {
    const pages = buildLineAtlasPages(collection([equatorLine]), {
      segmentKm: 25,
    });
    let prevWest = -Infinity;
    for (const p of pages) {
      const [w, s, e, n] = p.bounds;
      assert.ok(e > w, "bounds must have width");
      assert.ok(w >= prevWest, "segments advance along the line");
      assert.ok(s <= 0 && n >= 0);
      prevWest = w;
    }
    // Adjacent segments share their cut point.
    assert.ok(Math.abs(pages[0].bounds[2] - pages[1].bounds[0]) < 1e-9);
  });

  it("skips non-line features and applies the filter to line features", () => {
    const point = feature({ river: "NotALine" }, [5, 5]);
    const southern: Feature = {
      ...equatorLine,
      properties: { river: "Southern", region: "south" },
    };
    const pages = buildLineAtlasPages(collection([point, equatorLine, southern]), {
      segmentKm: 60,
      nameField: "river",
      filter: parseAtlasFilter('region = "south"'),
    });
    assert.equal(pages.length, 2);
    assert.ok(pages.every((p) => p.name.startsWith("Southern")));
  });

  it("continues chainage across MultiLineString parts without measuring gaps", () => {
    const multi: Feature = {
      type: "Feature",
      properties: {},
      geometry: {
        type: "MultiLineString",
        coordinates: [
          [
            [0, 0],
            [0.5, 0],
          ],
          [
            [0.6, 0],
            [1.1, 0],
          ],
        ],
      },
    };
    const pages = buildLineAtlasPages(collection([multi]), { segmentKm: 40 });
    // Two 55.6 km parts = 111.2 km of measured line (the 0.1 degree gap adds
    // nothing): 40 + 40 + 31.2.
    assert.equal(pages.length, 3);
    assert.equal(pages[2].properties.km_end, 111.2);
    assert.equal(pages[0].name, "Line 1 km 0-40");
  });

  it("returns no pages for a non-positive segment length", () => {
    assert.deepEqual(buildLineAtlasPages(collection([equatorLine]), { segmentKm: 0 }), []);
    assert.deepEqual(buildLineAtlasPages(collection([equatorLine]), { segmentKm: NaN }), []);
  });

  it("keeps per-feature sourceIndex distinct across multiple lines", () => {
    const second: Feature = {
      ...equatorLine,
      properties: { river: "Second" },
    };
    const pages = buildLineAtlasPages(collection([equatorLine, second]), {
      segmentKm: 60,
    });
    assert.deepEqual(
      pages.map((p) => p.sourceIndex),
      [0, 0, 1, 1],
    );
    assert.deepEqual(
      pages.map((p) => p.index),
      [0, 1, 2, 3],
    );
  });

  it("caps a runaway series at MAX_LINE_ATLAS_PAGES", () => {
    const pages = buildLineAtlasPages(collection([equatorLine]), {
      segmentKm: 0.01,
    });
    assert.equal(pages.length, MAX_LINE_ATLAS_PAGES);
  });

  it("finds lines nested in GeometryCollections", () => {
    const nested: Feature = {
      type: "Feature",
      properties: {},
      geometry: {
        type: "GeometryCollection",
        geometries: [{ type: "Point", coordinates: [9, 9] }, equatorLine.geometry],
      },
    };
    assert.equal(hasLineGeometry(nested.geometry), true);
    assert.equal(hasLineGeometry({ type: "Point", coordinates: [0, 0] }), false);
    const pages = buildLineAtlasPages(collection([nested]), { segmentKm: 60 });
    assert.equal(pages.length, 2);
  });

  it("cuts antimeridian-crossing edges across the dateline, not through 0", () => {
    const crossing: Feature = {
      type: "Feature",
      properties: {},
      geometry: {
        type: "LineString",
        coordinates: [
          [179, 0],
          [-179, 0],
        ],
      },
    };
    // ~222 km edge cut at 100 km: the interpolated cut points must stay near
    // 180 degrees (in the unwrapped frame), never near 0.
    const pages = buildLineAtlasPages(collection([crossing]), {
      segmentKm: 100,
    });
    assert.equal(pages.length, 3);
    for (const p of pages) {
      const [w, , e] = p.bounds;
      assert.ok(w >= 179 && e <= 181, `bounds ${p.bounds} left the dateline`);
      assert.ok(e - w < 2);
    }
  });
});