package com.example.aiapp

import androidx.compose.foundation.clickable
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.Spacer
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.width
import androidx.compose.material3.Card
import androidx.compose.material3.CircularProgressIndicator
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.unit.dp

/**
 * A model's working, shut until somebody asks for it.
 *
 * Shut by default, like a tool call and a memory note and for the same reason: it is not what the
 * session said, and left open it puts the reasoning between the question and the answer -- which on
 * a small model is most of the conversation.
 *
 * The heading is the whole of what the reader gets for free, so it carries the one thing worth
 * knowing without opening anything: whether this is still going, and if not how long it took. A
 * spinner while it runs, because that is the same fact a running command reports and it is drawn
 * the same way here.
 */
@Composable
fun ThinkingCard(
    item: TranscriptItem.ThinkingRow,
    expanded: Boolean,
    onToggle: () -> Unit,
    modifier: Modifier = Modifier,
) {
    Card(modifier.fillMaxWidth().clickable(onClick = onToggle)) {
        Column(Modifier.padding(12.dp)) {
            Row(verticalAlignment = Alignment.CenterVertically) {
                Text(thinkingHeadline(item), style = MaterialTheme.typography.titleSmall)
                Spacer(Modifier.width(8.dp))
                if (item.open) {
                    CircularProgressIndicator(
                        modifier = Modifier.width(16.dp).height(16.dp),
                        strokeWidth = 2.dp,
                    )
                }
            }
            if (expanded) {
                // Plain text rather than markdown: this is a model talking to itself, so its
                // half-finished lists and stray backticks are not markup it meant to write, and
                // rendering them as such makes the working look like an answer.
                Text(
                    item.text,
                    style = MaterialTheme.typography.bodySmall,
                    color = MaterialTheme.colorScheme.onSurfaceVariant,
                    modifier = Modifier.padding(top = 6.dp),
                )
            }
        }
    }
}

/**
 * "Thinking", "Thought for 12.4s", or "Thought".
 *
 * The third is the one worth keeping: a block whose turn ended before the model said anything --
 * interrupted, stopped, a process that exited -- was thought about for a length of time nobody
 * measured. Naming a span there would be this screen inventing one, and the reader has no way to
 * tell an invented one from the rest.
 */
fun thinkingHeadline(item: TranscriptItem.ThinkingRow): String =
    when {
        item.open -> "Thinking"
        item.ms != null -> "Thought for ${formatMillis(item.ms)}"
        else -> "Thought"
    }