package com.example.androidapp.nmea

import org.junit.Assert.*
import org.junit.Before
import org.junit.Test

class NmeaParserTest {

    private lateinit var parser: NmeaParser

    @Before
    fun setUp() {
        parser = NmeaParser()
    }

    // $GPRMC,123519,A,4807.038,N,01131.000,E,022.4,084.4,230394,003.1,W*6A
    // lat: 48 + 7.038/60 = 48.1173°N, lon: 11 + 31.000/60 = 11.51667°E
    // SOG 22.4 kn, COG 84.4°

    @Test
    fun `valid RMC sentence parses latitude and longitude`() {
        val sentence = "\$GPRMC,123519,A,4807.038,N,01131.000,E,022.4,084.4,230394,003.1,W*6A"
        val pos = parser.parseRmc(sentence)
        assertNotNull(pos)
        assertEquals(48.1173, pos!!.latitude, 0.0001)
        assertEquals(11.51667, pos.longitude, 0.0001)
    }

    @Test
    fun `valid RMC sentence parses SOG and COG`() {
        val sentence = "\$GPRMC,123519,A,4807.038,N,01131.000,E,022.4,084.4,230394,003.1,W*6A"
        val pos = parser.parseRmc(sentence)
        assertNotNull(pos)
        assertEquals(22.4, pos!!.sog, 0.001)
        assertEquals(84.4, pos.cog, 0.001)
    }

    @Test
    fun `void status V returns null`() {
        val sentence = "\$GPRMC,123519,V,4807.038,N,01131.000,E,,,230394,003.1,W"
        assertNull(parser.parseRmc(sentence))
    }

    @Test
    fun `malformed sentence with too few fields returns null`() {
        assertNull(parser.parseRmc("\$GPRMC,123519,A"))
    }

    @Test
    fun `empty string returns null`() {
        assertNull(parser.parseRmc(""))
    }

    @Test
    fun `non-RMC sentence returns null`() {
        val sentence = "\$GPGGA,123519,4807.038,N,01131.000,E,1,08,0.9,545.4,M,46.9,M,,"
        assertNull(parser.parseRmc(sentence))
    }

    @Test
    fun `south latitude is negative`() {
        // lat: -(42 + 50.5589/60) = -42.84265
        val sentence = "\$GPRMC,092204.999,A,4250.5589,S,14718.5084,E,0.00,89.68,211200,,"
        val pos = parser.parseRmc(sentence)
        assertNotNull(pos)
        assertTrue("South latitude must be negative", pos!!.latitude < 0)
        assertEquals(-42.84265, pos.latitude, 0.0001)
    }

    @Test
    fun `west longitude is negative`() {
        // lon: -(11 + 31.000/60) = -11.51667
        val sentence = "\$GPRMC,123519,A,4807.038,N,01131.000,W,022.4,084.4,230394,003.1,E"
        val pos = parser.parseRmc(sentence)
        assertNotNull(pos)
        assertTrue("West longitude must be negative", pos!!.longitude < 0)
        assertEquals(-11.51667, pos.longitude, 0.0001)
    }

    @Test
    fun `SOG and COG parse with decimal precision`() {
        val sentence = "\$GPRMC,093456,A,3352.1234,N,11801.5678,W,12.345,270.5,140326,,"
        val pos = parser.parseRmc(sentence)
        assertNotNull(pos)
        assertEquals(12.345, pos!!.sog, 0.0001)
        assertEquals(270.5, pos.cog, 0.0001)
    }

    @Test
    fun `empty SOG and COG fields default to zero`() {
        val sentence = "\$GPRMC,123519,A,4807.038,N,01131.000,E,,,230394,003.1,W"
        val pos = parser.parseRmc(sentence)
        assertNotNull(pos)
        assertEquals(0.0, pos!!.sog, 0.001)
        assertEquals(0.0, pos.cog, 0.001)
    }

    @Test
    fun `GNRMC talker ID is also accepted`() {
        val sentence = "\$GNRMC,123519,A,4807.038,N,01131.000,E,022.4,084.4,230394,003.1,W"
        val pos = parser.parseRmc(sentence)
        assertNotNull(pos)
        assertEquals(48.1173, pos!!.latitude, 0.0001)
    }
}