Render apply_patch tool calls as structured diffs

app/src/main/java/dev/blazelight/p4oc/ui/components/toolwidgets/ApplyPatchToolWidget.kt

@@ -0,0 +1,173 @@
+package dev.blazelight.p4oc.ui.components.toolwidgets
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.horizontalScroll
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.heightIn
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.semantics.Role
+import androidx.compose.ui.text.font.FontFamily
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import dev.blazelight.p4oc.domain.model.Part
+import dev.blazelight.p4oc.ui.theme.LocalOpenCodeTheme
+import dev.blazelight.p4oc.ui.theme.SemanticColors
+import dev.blazelight.p4oc.ui.theme.Spacing
+import dev.blazelight.p4oc.ui.theme.TuiCodeFontSize
+import kotlinx.serialization.json.contentOrNull
+import kotlinx.serialization.json.jsonPrimitive
+
+internal enum class PatchFileAction(val marker: String) {
+    ADD("A"),
+    UPDATE("M"),
+    DELETE("D"),
+}
+
+internal data class PatchFileChange(
+    val path: String,
+    val action: PatchFileAction,
+)
+
+internal fun patchText(tool: Part.Tool): String? =
+    tool.state.input["patchText"]?.jsonPrimitive?.contentOrNull
+        ?: tool.state.input["patch"]?.jsonPrimitive?.contentOrNull
+
+internal fun parseApplyPatchFiles(patch: String): List<PatchFileChange> = patch.lineSequence()
+    .mapNotNull { line ->
+        PATCH_FILE_HEADERS.firstNotNullOfOrNull { (prefix, action) ->
+            line.removePrefix(prefix).takeIf { it != line && it.isNotBlank() }
+                ?.let { PatchFileChange(path = it.trim(), action = action) }
+        }
+    }
+    .distinctBy { it.action to it.path }
+    .toList()
+
+internal fun applyPatchCompactDescription(tool: Part.Tool): String {
+    val count = patchText(tool)?.let(::parseApplyPatchFiles)?.size ?: 0
+    return if (count > 0) "Patch: $count file(s)" else "Apply patch"
+}
+
+@Composable
+@Suppress("FunctionNaming")
+internal fun ApplyPatchWidgetExpanded(
+    tool: Part.Tool,
+    onClick: (() -> Unit)?,
+    modifier: Modifier = Modifier,
+) {
+    val patch = patchText(tool)
+    val files = patch?.let(::parseApplyPatchFiles).orEmpty()
+    if (patch == null || files.isEmpty()) {
+        DefaultWidgetExpanded(
+            tool = tool,
+            onClick = onClick,
+            showApprovalActions = false,
+            onToolApprove = {},
+            onToolDeny = {},
+            modifier = modifier,
+        )
+        return
+    }
+
+    val theme = LocalOpenCodeTheme.current
+    Column(
+        modifier = modifier
+            .then(if (onClick != null) Modifier.clickable(role = Role.Button, onClick = onClick) else Modifier)
+            .background(theme.backgroundPanel.copy(alpha = 0.5f))
+            .padding(Spacing.md),
+        verticalArrangement = Arrangement.spacedBy(Spacing.sm),
+    ) {
+        Text(
+            text = applyPatchCompactDescription(tool),
+            style = MaterialTheme.typography.labelMedium.copy(
+                fontFamily = FontFamily.Monospace,
+                fontSize = TuiCodeFontSize.lg,
+            ),
+            color = theme.text,
+        )
+        files.forEach { change -> PatchFileRow(change) }
+        Box(
+            modifier = Modifier
+                .fillMaxWidth()
+                .heightIn(max = 240.dp)
+                .background(theme.backgroundElement)
+                .horizontalScroll(rememberScrollState())
+                .verticalScroll(rememberScrollState())
+                .padding(Spacing.sm),
+        ) {
+            Column {
+                patch.lineSequence()
+                    .filterNot { it == "*** Begin Patch" || it == "*** End Patch" }
+                    .forEach { line -> PatchLine(line) }
+            }
+        }
+    }
+}
+
+@Composable
+@Suppress("FunctionNaming")
+private fun PatchFileRow(change: PatchFileChange) {
+    val theme = LocalOpenCodeTheme.current
+    val color = when (change.action) {
+        PatchFileAction.ADD -> theme.success
+        PatchFileAction.UPDATE -> theme.accent
+        PatchFileAction.DELETE -> theme.error
+    }
+    Row(
+        modifier = Modifier.fillMaxWidth(),
+        horizontalArrangement = Arrangement.spacedBy(Spacing.sm),
+        verticalAlignment = Alignment.CenterVertically,
+    ) {
+        Text(change.action.marker, color = color, fontFamily = FontFamily.Monospace)
+        Text(
+            text = change.path,
+            modifier = Modifier.weight(1f),
+            style = MaterialTheme.typography.labelSmall,
+            color = theme.textMuted,
+            fontFamily = FontFamily.Monospace,
+            maxLines = 1,
+            overflow = TextOverflow.Ellipsis,
+        )
+    }
+}
+
+@Composable
+@Suppress("FunctionNaming")
+private fun PatchLine(line: String) {
+    val theme = LocalOpenCodeTheme.current
+    val (background, foreground) = when {
+        line.startsWith("*** Add File:") -> theme.success.copy(alpha = 0.12f) to theme.success
+        line.startsWith("*** Update File:") -> theme.accent.copy(alpha = 0.12f) to theme.accent
+        line.startsWith("*** Delete File:") -> theme.error.copy(alpha = 0.12f) to theme.error
+        line.startsWith("+") -> SemanticColors.Diff.addedBackground to SemanticColors.Diff.addedText
+        line.startsWith("-") -> SemanticColors.Diff.removedBackground to SemanticColors.Diff.removedText
+        line.startsWith("@@") -> theme.accent.copy(alpha = 0.1f) to theme.accent
+        else -> Color.Transparent to theme.textMuted
+    }
+    Text(
+        text = line,
+        modifier = Modifier.background(background).padding(horizontal = Spacing.xs),
+        style = MaterialTheme.typography.bodySmall,
+        color = foreground,
+        fontFamily = FontFamily.Monospace,
+        fontSize = TuiCodeFontSize.sm,
+    )
+}
+
+private val PATCH_FILE_HEADERS = listOf(
+    "*** Add File:" to PatchFileAction.ADD,
+    "*** Update File:" to PatchFileAction.UPDATE,
+    "*** Delete File:" to PatchFileAction.DELETE,
+)

app/src/main/java/dev/blazelight/p4oc/ui/components/toolwidgets/ToolCallWidget.kt

@@ -242,6 +242,11 @@ fun ToolCallExpanded(
             onOpenSubSession = onOpenSubSession,
             modifier = modifier
         )
+        "apply_patch" -> ApplyPatchWidgetExpanded(
+            tool = tool,
+            onClick = onClick,
+            modifier = modifier,
+        )
         else -> DefaultWidgetExpanded(
             tool = tool,
             onClick = onClick,
@@ -303,6 +308,7 @@ private fun getToolCompactDescription(tool: Part.Tool): String {
             val pattern = extractParam(input, "pattern") ?: extractParam(input, "substring_pattern")
             pattern?.take(40)?.let { "Search: $it" } ?: tool.toolName
         }
+        name == "apply_patch" -> applyPatchCompactDescription(tool)
         else -> tool.toolName
     }
 }

app/src/test/java/dev/blazelight/p4oc/ui/components/toolwidgets/ApplyPatchToolWidgetTest.kt

@@ -0,0 +1,61 @@
+package dev.blazelight.p4oc.ui.components.toolwidgets
+
+import dev.blazelight.p4oc.domain.model.Part
+import dev.blazelight.p4oc.domain.model.ToolState
+import kotlinx.serialization.json.buildJsonObject
+import kotlinx.serialization.json.put
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class ApplyPatchToolWidgetTest {
+    @Test
+    fun `parses add update and delete file headers`() {
+        val files = parseApplyPatchFiles(
+            """
+            *** Begin Patch
+            *** Update File: src/Main.kt
+            @@
+            -old
+            +new
+            *** Add File: src/New.kt
+            +content
+            *** Delete File: src/Old.kt
+            *** End Patch
+            """.trimIndent()
+        )
+
+        assertEquals(
+            listOf(
+                PatchFileChange("src/Main.kt", PatchFileAction.UPDATE),
+                PatchFileChange("src/New.kt", PatchFileAction.ADD),
+                PatchFileChange("src/Old.kt", PatchFileAction.DELETE),
+            ),
+            files,
+        )
+    }
+
+    @Test
+    fun `compact description reports changed file count`() {
+        val tool = Part.Tool(
+            id = "part",
+            sessionID = "session",
+            messageID = "message",
+            callID = "call",
+            toolName = "apply_patch",
+            state = ToolState.Completed(
+                input = buildJsonObject {
+                    put(
+                        "patchText",
+                        "*** Begin Patch\n*** Update File: a.kt\n*** Add File: b.kt\n*** End Patch"
+                    )
+                },
+                output = "Success",
+                title = "Applied patch",
+                startedAt = 1,
+                endedAt = 2,
+            ),
+        )
+
+        assertEquals("Patch: 2 file(s)", applyPatchCompactDescription(tool))
+    }
+}