feat(fishing): FishingModeManager with target zone computation

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

2 files changed, 48 insertions, 0 deletions

diff --git a/android-app/app/src/main/kotlin/org/terst/nav/ui/fishing/FishingModeManager.kt b/android-app/app/src/main/kotlin/org/terst/nav/ui/fishing/FishingModeManager.kt
new file mode 100644
index 0000000..7ab1089
--- /dev/null
+++ b/android-app/app/src/main/kotlin/org/terst/nav/ui/fishing/FishingModeManager.kt
@@ -0,0 +1,32 @@
+package org.terst.nav.ui.fishing
+
+import android.content.Context
+
+class FishingModeManager(private val context: Context? = null) {
+
+    private val prefs get() = context?.getSharedPreferences("fishing_mode", Context.MODE_PRIVATE)
+
+    var isActive: Boolean
+        get() = prefs?.getBoolean("active", false) ?: false
+        set(v) { prefs?.edit()?.putBoolean("active", v)?.apply() }
+
+    fun computeTarget(
+        boatLat: Double, boatLon: Double, boatCogDeg: Double,
+        tempC: Double, currentKt: Double, currentDirDeg: Double
+    ): FishingTarget? {
+        if (currentKt < 0.1) return null
+
+        val crossCurrentBearing = (currentDirDeg + 90.0) % 360.0
+        val estimatedDistNm = (3.0 + currentKt * 2.5).coerceIn(3.0, 8.0)
+        val rig = RigAdvisor.recommend(tempC, currentKt, windKt = 0.0)
+        val tempF = tempC * 9.0 / 5.0 + 32.0
+        val zoneDesc = "%.0f°F water, %.1f kt current — steer to color edge".format(tempF, currentKt)
+
+        return FishingTarget(
+            bearingDeg = crossCurrentBearing,
+            distanceNm = estimatedDistNm,
+            zoneDescription = zoneDesc,
+            rig = rig
+        )
+    }
+}
diff --git a/android-app/app/src/test/kotlin/org/terst/nav/ui/fishing/FishingModeManagerTest.kt b/android-app/app/src/test/kotlin/org/terst/nav/ui/fishing/FishingModeManagerTest.kt
new file mode 100644
index 0000000..7840b52
--- /dev/null
+++ b/android-app/app/src/test/kotlin/org/terst/nav/ui/fishing/FishingModeManagerTest.kt
@@ -0,0 +1,16 @@
+package org.terst.nav.ui.fishing
+
+import org.junit.Assert.*
+import org.junit.Test
+
+class FishingModeManagerTest {
+    @Test fun `target zone computed from current bearing and temp break`() {
+        val mgr = FishingModeManager()
+        val target = mgr.computeTarget(
+            boatLat = 19.5, boatLon = -156.0, boatCogDeg = 270.0,
+            tempC = 25.0, currentKt = 1.2, currentDirDeg = 180.0
+        )
+        assertNotNull(target)
+        assertTrue(target!!.distanceNm in 0.5..20.0)
+    }
+}