ai-app/app/androidApp/src/main/kotlin/com/example/aiapp/ToolInput.kt

package com.example.aiapp

import androidx.compose.foundation.horizontalScroll
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.rememberScrollState
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.Text
import androidx.compose.runtime.Composable
import androidx.compose.runtime.remember
import androidx.compose.ui.Modifier
import androidx.compose.ui.text.font.FontFamily
import androidx.compose.ui.unit.dp
import org.json.JSONObject

/**
 * A tool call's input, read rather than dumped.
 *
 * Every tool's input arrives as JSON, and showing it raw makes the reader parse
 * `{"command":"…","timeout":120000}` themselves to find the one line they care about. So the fields
 * that carry the meaning are pulled out, and anything left over is still shown, because dropping a
 * field would be claiming the tool has no other input when it might.
 */
data class ToolInput(
    /** The thing that will actually be run or read, if this tool has one. */
    val subject: String?,
    /** The language [subject] is written in, for highlighting. */
    val language: Language?,
    /** The tool's own one-line summary, when it wrote one. */
    val description: String?,
    /**
     * How long the call may take, in the largest units it fits. Shown apart because it is a limit
     * on the call rather than part of what the call does.
     */
    val timeout: String?,
    /** Everything else, as `name: value` lines. Never dropped. */
    val rest: List<String>,
) {
    /** The one line to show when there is only room for one: what this call is for. */
    val title: String?
        get() = description ?: subject
}

/**
 * Which field of which tool is the subject.
 *
 * A table rather than a chain of `if`s: adding a tool is a row, and the shape stops any of them
 * from being the special case that gets its own code path. Unknown tools fall through to "no
 * subject, everything is rest".
 */
private val SUBJECTS: Map<String, Pair<String, Language?>> =
    mapOf(
        "Bash" to ("command" to Language.SHELL),
        "Read" to ("file_path" to null),
        "Write" to ("file_path" to null),
        "Edit" to ("file_path" to null),
        "Glob" to ("pattern" to null),
        "Grep" to ("pattern" to null),
        "WebFetch" to ("url" to null),
    )

/** Fields that are the tool's own prose about itself rather than input to it. */
private val DESCRIPTIONS = listOf("description", "prompt")

fun parseToolInput(tool: String, input: String): ToolInput {
    val json =
        try {
            JSONObject(input)
        } catch (_: org.json.JSONException) {
            // Not an object: older transcripts and some tools send a bare string. It is still the
            // input, so it is still shown.
            return ToolInput(
                null,
                null,
                null,
                null,
                input.takeIf { it.isNotBlank() }?.let { listOf(it) }.orEmpty(),
            )
        }
    val (subjectKey, language) = SUBJECTS[tool] ?: (null to null)
    val subject = subjectKey?.let { json.optString(it) }?.takeIf { it.isNotBlank() }
    val description = DESCRIPTIONS.firstNotNullOfOrNull {
        json.optString(it).takeIf { v -> v.isNotBlank() }
    }
    val timeout = json.optString("timeout").takeIf { it.isNotBlank() }?.let { formatMillisText(it) }
    val rest =
        json
            .keys()
            .asSequence()
            .filter { it != subjectKey || subject == null }
            .filter { it !in DESCRIPTIONS || description == null }
            .filter { it != "timeout" || timeout == null }
            .sorted()
            .map { key -> "$key: ${json.get(key)}" }
            .toList()
    return ToolInput(subject, language, description, timeout, rest)
}

/**
 * A tool call's input: its subject highlighted, then whatever else it carried.
 *
 * On the dark surface every verbatim thing in the app sits on. Drawn as nothing at all when the
 * call carried neither, rather than as an empty block: a tinted rectangle with nothing in it is a
 * rendering fault.
 *
 * The description is *not* here. It is the tool's own prose about what it is doing, so it belongs
 * with the reader's text rather than inside the machine's; [ToolCard] draws it above this.
 */
@Composable
fun ToolInputView(tool: String, input: String, modifier: Modifier = Modifier) {
    val parsed = remember(tool, input) { parseToolInput(tool, input) }
    if (parsed.subject == null && parsed.rest.isEmpty()) return
    RawBlock(modifier) {
        parsed.subject?.let { subject ->
            // Not wrapped: a wrapped command hides where its arguments end, and the long one is the
            // one being read closely.
            Text(
                // Not cached: a tool's subject is one command line, which lexes in microseconds --
                // the cache exists for a fence with two hundred lines in it.
                remember(subject, parsed.language) { highlight(subject, parsed.language) },
                style = MaterialTheme.typography.bodySmall,
                fontFamily = FontFamily.Monospace,
                softWrap = false,
                modifier = Modifier.fillMaxWidth().horizontalScroll(rememberScrollState()),
            )
        }
        parsed.rest.forEach {
            Text(
                it,
                style = MaterialTheme.typography.bodySmall,
                fontFamily = FontFamily.Monospace,
                color = MaterialTheme.colorScheme.onSurfaceVariant,
                modifier = Modifier.padding(top = 2.dp),
            )
        }
    }
}