package cc.unitmesh.agent.diff

import kotlin.test.Test
import kotlin.test.assertEquals
import kotlin.test.assertNotNull
import kotlin.test.assertTrue

class DiffParserTest {
    @Test
    fun `should parse standard unified diff`() {
        val diff =
            """
            --- a/File.kt
            +++ b/File.kt
            @@ -1,3 +1,3 @@
             context line
            -deleted line
            +added line
             another context
            """.trimIndent()

        val fileDiffs = DiffParser.parse(diff)

        assertEquals(1, fileDiffs.size)
        assertEquals("File.kt", fileDiffs[0].newPath)
        assertEquals("File.kt", fileDiffs[0].oldPath)
        assertEquals(1, fileDiffs[0].hunks.size)

        val hunk = fileDiffs[0].hunks[0]
        assertEquals(4, hunk.lines.size)
        assertEquals(DiffLineType.CONTEXT, hunk.lines[0].type)
        assertEquals(DiffLineType.DELETED, hunk.lines[1].type)
        assertEquals(DiffLineType.ADDED, hunk.lines[2].type)
        assertEquals(DiffLineType.CONTEXT, hunk.lines[3].type)
    }

    @Test
    fun `should parse multiple hunks`() {
        val diff =
            """
            --- a/File.kt
            +++ b/File.kt
            @@ -1,3 +1,3 @@
             line 1
            -old line
            +new line
             line 3
            @@ -10,2 +10,3 @@
             line 10
            +added line
             line 11
            """.trimIndent()

        val fileDiffs = DiffParser.parse(diff)

        assertEquals(1, fileDiffs.size)
        assertEquals(2, fileDiffs[0].hunks.size)
    }

    @Test
    fun `should parse multiple files`() {
        val diff =
            """
            --- a/File1.kt
            +++ b/File1.kt
            @@ -1,2 +1,2 @@
            -old1
            +new1
            --- a/File2.kt
            +++ b/File2.kt
            @@ -1,2 +1,2 @@
            -old2
            +new2
            """.trimIndent()

        val fileDiffs = DiffParser.parse(diff)

        assertEquals(2, fileDiffs.size)
        assertEquals("File1.kt", fileDiffs[0].newPath)
        assertEquals("File2.kt", fileDiffs[1].newPath)
    }

    @Test
    fun `should parse new file`() {
        val diff =
            """
            --- /dev/null
            +++ b/NewFile.kt
            @@ -0,0 +1,3 @@
            +line 1
            +line 2
            +line 3
            """.trimIndent()

        val fileDiffs = DiffParser.parse(diff)

        assertEquals(1, fileDiffs.size)
        assertTrue(fileDiffs[0].isNewFile)
        assertEquals("NewFile.kt", fileDiffs[0].newPath)
    }

    @Test
    fun `should parse deleted file`() {
        val diff =
            """
            --- a/OldFile.kt
            +++ /dev/null
            @@ -1,3 +0,0 @@
            -line 1
            -line 2
            -line 3
            """.trimIndent()

        val fileDiffs = DiffParser.parse(diff)

        assertEquals(1, fileDiffs.size)
        assertTrue(fileDiffs[0].isDeletedFile)
        assertEquals("OldFile.kt", fileDiffs[0].oldPath)
    }

    @Test
    fun `should parse diff without file headers`() {
        val diff =
            """
            @@ -1,4 +1,5 @@
             First line
            -Second line
            +Modified line
            +Added line
             Last line
            """.trimIndent()

        val fileDiffs = DiffParser.parse(diff)

        assertEquals(1, fileDiffs.size)
        assertEquals(1, fileDiffs[0].hunks.size)
        assertEquals(5, fileDiffs[0].hunks[0].lines.size)
    }

    @Test
    fun `should track line numbers correctly`() {
        val diff =
            """
            @@ -10,5 +10,6 @@
             line 10
             line 11
            -line 12 deleted
            +line 12 modified
            +line 13 added
             line 14
             line 15
            """.trimIndent()

        val fileDiffs = DiffParser.parse(diff)
        val lines = fileDiffs[0].hunks[0].lines

        // 检查旧行号
        assertEquals(10, lines[0].oldLineNumber)
        assertEquals(11, lines[1].oldLineNumber)
        assertEquals(12, lines[2].oldLineNumber)

        // 检查新行号
        assertEquals(10, lines[0].newLineNumber)
        assertEquals(11, lines[1].newLineNumber)
        assertEquals(12, lines[3].newLineNumber) // added line
        assertEquals(13, lines[4].newLineNumber) // added line
    }

    @Test
    fun `should handle empty lines in diff`() {
        val diff =
            """
            @@ -1,3 +1,3 @@
             line 1

             line 3
            """.trimIndent()

        val fileDiffs = DiffParser.parse(diff)

        assertNotNull(fileDiffs)
        assertEquals(1, fileDiffs.size)
    }
}