Add core engine: tarot + astrology reading generator with CLI and i18n

Plain-C, dependency-free engine that produces a personalized daily Celtic Cross tarot spread and natal-chart/transit astrology reading, plus a standalone CLI (dist/deck-engine) and run.sh wrapper. Includes English/German output via a simple key=value translation format, and docs/diagrams describing the architecture and I/O.
2026-07-04 06:49:18 +02:00
commit a93e5d4cdc
60 changed files with 17134 additions and 0 deletions
@@ -0,0 +1,122 @@
+#include <assert.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "../src/reading.h"
+#include "../src/i18n.h"
+
+static void test_tarot_determinism(void) {
+  CelticCrossSpread a, b, c;
+  tarot_draw_celtic_cross("2026-07-03", &a);
+  tarot_draw_celtic_cross("2026-07-03", &b);
+  tarot_draw_celtic_cross("2026-07-04", &c);
+
+  for (int i = 0; i < TAROT_SPREAD_SIZE; i++) {
+    assert(a.positions[i].card == b.positions[i].card);
+    assert(a.positions[i].reversed == b.positions[i].reversed);
+  }
+
+  int differs = 0;
+  for (int i = 0; i < TAROT_SPREAD_SIZE; i++) {
+    if (a.positions[i].card != c.positions[i].card ||
+        a.positions[i].reversed != c.positions[i].reversed) {
+      differs = 1;
+      break;
+    }
+  }
+  assert(differs && "different seeds should (almost always) differ");
+
+  /* No repeated cards within a single spread. */
+  for (int i = 0; i < TAROT_SPREAD_SIZE; i++) {
+    for (int j = i + 1; j < TAROT_SPREAD_SIZE; j++) {
+      assert(a.positions[i].card != a.positions[j].card);
+    }
+  }
+
+  printf("PASS test_tarot_determinism\n");
+}
+
+static void test_natal_sun_sign(void) {
+  /* 2000-06-15 noon UTC: the Sun is well inside Gemini (60-90 degrees),
+   * away from any sign boundary, so this is a stable regression check
+   * against the ephemeris math. Birth location doesn't affect the Sun's
+   * geocentric ecliptic longitude, only the Ascendant. */
+  BirthData birth = {
+    .year = 2000, .month = 6, .day = 15,
+    .hour = 12, .minute = 0,
+    .utc_offset_hours = 0.0,
+    .latitude = 52.5, .longitude = 13.4,
+  };
+
+  NatalChart chart;
+  astro_compute_natal_chart(&birth, &chart);
+
+  assert(chart.bodies[PLANET_SUN].sign == SIGN_GEMINI);
+  printf("PASS test_natal_sun_sign\n");
+}
+
+static void test_reading_generate_smoke(void) {
+  BirthData birth = {
+    .year = 1990, .month = 5, .day = 14,
+    .hour = 14, .minute = 32,
+    .utc_offset_hours = 2.0,
+    .latitude = 52.52, .longitude = 13.405,
+  };
+
+  DailyReading r1, r2;
+  reading_generate("smoke-test-seed", &birth, 1751500000, &r1);
+  reading_generate("smoke-test-seed", &birth, 1751500000, &r2);
+
+  for (int i = 0; i < TAROT_SPREAD_SIZE; i++) {
+    assert(r1.spread.positions[i].card == r2.spread.positions[i].card);
+    assert(r1.spread.positions[i].reversed == r2.spread.positions[i].reversed);
+  }
+  for (int b = 0; b < NUM_BODIES; b++) {
+    assert(r1.natal.bodies[b].ecliptic_longitude == r2.natal.bodies[b].ecliptic_longitude);
+    assert(r1.transits.bodies[b].ecliptic_longitude == r2.transits.bodies[b].ecliptic_longitude);
+  }
+  assert(r1.transits.aspect_count == r2.transits.aspect_count);
+
+  printf("PASS test_reading_generate_smoke\n");
+}
+
+/* Run with cwd == engine/ (as `make test` does), so the shipped
+ * engine/i18n/ .lang files are reachable as i18n/<code>.lang. */
+static void test_i18n_fallback_and_translation(void) {
+  /* No catalog loaded yet: every lookup returns the caller's fallback. */
+  assert(strcmp(i18n_get("does.not.exist", "fallback text"), "fallback text") == 0);
+
+  bool loaded = i18n_load("i18n/de.lang");
+  assert(loaded && "expected engine/i18n/de.lang to exist and load");
+  assert(strcmp(i18n_get("body.sun", "Sun"), "Sonne") == 0);
+  assert(strcmp(i18n_get("does.not.exist", "fallback text"), "fallback text") == 0);
+
+  /* astro_ and tarot_ accessors route through the same loaded catalog. */
+  assert(strcmp(astro_body_name(PLANET_MOON), "Mond") == 0);
+  assert(strcmp(astro_sign_name(SIGN_LEO), "Löwe") == 0);
+  assert(strcmp(astro_moon_phase_name(MOON_FULL), "Vollmond") == 0);
+  assert(strcmp(astro_aspect_name(ASPECT_TRINE), "Trigon") == 0);
+  assert(strcmp(tarot_card_name(CARD_WORLD), "Die Welt") == 0);
+  assert(strcmp(tarot_position_name(POSITION_OUTCOME), "Das Ergebnis") == 0);
+
+  /* Loading a file that doesn't exist fails and leaves the previously
+   * loaded catalog in place, rather than silently clearing it. */
+  assert(!i18n_load("i18n/does-not-exist.lang"));
+  assert(strcmp(i18n_get("body.sun", "Sun"), "Sonne") == 0);
+
+  /* Loading a different language replaces the catalog wholesale. */
+  loaded = i18n_load("i18n/en.lang");
+  assert(loaded);
+  assert(strcmp(astro_body_name(PLANET_MOON), "Moon") == 0);
+
+  printf("PASS test_i18n_fallback_and_translation\n");
+}
+
+int main(void) {
+  test_tarot_determinism();
+  test_natal_sun_sign();
+  test_reading_generate_smoke();
+  test_i18n_fallback_and_translation();
+  printf("All smoke tests passed.\n");
+  return 0;
+}