package soy.iko.opencode.ui.chat

import androidx.compose.foundation.layout.Arrangement
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.text.selection.SelectionContainer
import androidx.compose.foundation.verticalScroll
import androidx.compose.material.icons.Icons
import androidx.compose.material.icons.filled.Shield
import androidx.compose.material3.AlertDialog
import androidx.compose.material3.Button
import androidx.compose.material3.Icon
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.OutlinedButton
import androidx.compose.material3.Text
import androidx.compose.material3.TextButton
import androidx.compose.runtime.Composable
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.getValue
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.platform.LocalHapticFeedback
import androidx.compose.ui.res.stringResource
import androidx.compose.ui.text.font.FontFamily
import androidx.compose.ui.unit.dp
import soy.iko.opencode.data.model.Permission
import soy.iko.opencode.data.model.PermissionResponse
import soy.iko.opencode.R

/**
 * Modal asking the user to approve a tool the agent wants to run. The agent run is
 * paused until one of these responses is sent. Non-dismissable by tap-outside so the
 * decision is explicit.
 */
@Composable
fun PermissionDialog(
    permission: Permission,
    onRespond: (PermissionResponse) -> Unit,
    position: Int = 0,
    total: Int = 0,
) {
    val haptics = LocalHapticFeedback.current
    // Guard against double-respond: back press + button tap, or rapid double-tap,
    // could call onRespond twice. Once a response is sent, subsequent calls are no-ops.
    // Keyed on permission.id: the host mounts this dialog against a conflating StateFlow,
    // so a null -> permissionB transition can collapse to just permissionB, reusing this
    // composable for a different permission. Without the key `responded` would stay true
    // and every button (and back-press) would be a no-op — an undismissable modal.
    // Plain `remember` (not `rememberSaveable`): a failed respondPermission re-enqueues
    // the same permission id (ChatViewModel.respondPermission -> enqueuePermission), and
    // rememberSaveable would restore a stale `true` from the Bundle across a config
    // change in between, locking the re-queued modal with all buttons no-op. Plain
    // remember resets to false on every fresh composition, so a re-queued permission is
    // always answerable.
    var responded by remember(permission.id) { mutableStateOf(false) }
    val respond: (PermissionResponse) -> Unit = { response ->
        if (!responded) {
            responded = true
            onRespond(response)
        }
    }
    AlertDialog(
        // Back press routes here (dismissOnBackPress defaults true) and is treated as an
        // explicit reject — the safe default. Tap-outside is disabled below so it can't
        // dismiss silently. A host-composition BackHandler doesn't work: AlertDialog
        // renders in its own window whose back dispatcher never reaches the host.
        onDismissRequest = { respond(PermissionResponse.REJECT) },
        properties = androidx.compose.ui.window.DialogProperties(dismissOnClickOutside = false),
        icon = { Icon(Icons.Filled.Shield, contentDescription = null) },
        title = {
            Column(verticalArrangement = Arrangement.spacedBy(2.dp)) {
                // A backlog indicator ("N of M") when more than one request is queued, so the
                // user knows the newest dialog isn't the only pending decision.
                if (total > 1) {
                    Text(
                        stringResource(R.string.permission_progress, position, total),
                        style = MaterialTheme.typography.labelMedium,
                        color = MaterialTheme.colorScheme.onSurfaceVariant,
                    )
                }
                Text(permission.title ?: stringResource(R.string.permission_title))
            }
        },
        text = {
            Column(verticalArrangement = Arrangement.spacedBy(8.dp)) {
                // The command / pattern can be long or multi-line; make it selectable and cap
                // its height with an inner scroll so it can't push the Allow/Reject buttons off
                // screen. Keeps the monospace styling.
                SelectionContainer {
                    Column(
                        modifier = Modifier
                            .heightIn(max = 200.dp)
                            .verticalScroll(rememberScrollState()),
                        verticalArrangement = Arrangement.spacedBy(8.dp),
                    ) {
                        permission.type?.let {
                            Text(it, style = MaterialTheme.typography.labelLarge, fontFamily = FontFamily.Monospace)
                        }
                        permission.patternText?.let {
                            Text(
                                it,
                                style = MaterialTheme.typography.bodyMedium,
                                fontFamily = FontFamily.Monospace,
                                color = MaterialTheme.colorScheme.onSurfaceVariant,
                            )
                        }
                    }
                }
                Text(
                    stringResource(R.string.permission_text),
                    style = MaterialTheme.typography.bodySmall,
                    color = MaterialTheme.colorScheme.onSurfaceVariant,
                )
            }
        },
        confirmButton = {
            // At very large font scales (200%+ accessibility text scale) the four full-width
            // buttons can overflow the dialog's max height, pushing Reject off-screen and
            // making it unreachable — the opposite of safe. Scroll + cap the column so the
            // full set stays answerable; vertically centering when it fits keeps the look
            // unchanged at normal scales.
            Column(
                modifier = Modifier
                    .fillMaxWidth()
                    .heightIn(max = 320.dp)
                    .verticalScroll(rememberScrollState()),
                verticalArrangement = Arrangement.spacedBy(4.dp),
            ) {
                Button(
                    onClick = {
                        haptics.performHapticFeedback(androidx.compose.ui.hapticfeedback.HapticFeedbackType.LongPress)
                        respond(PermissionResponse.ONCE)
                    },
                    modifier = Modifier.fillMaxWidth(),
                ) { Text(stringResource(R.string.allow_once)) }
                OutlinedButton(
                    onClick = {
                        haptics.performHapticFeedback(androidx.compose.ui.hapticfeedback.HapticFeedbackType.LongPress)
                        respond(PermissionResponse.SESSION)
                    },
                    modifier = Modifier.fillMaxWidth(),
                ) { Text(stringResource(R.string.allow_for_session)) }
                OutlinedButton(
                    onClick = {
                        haptics.performHapticFeedback(androidx.compose.ui.hapticfeedback.HapticFeedbackType.LongPress)
                        respond(PermissionResponse.ALWAYS)
                    },
                    modifier = Modifier.fillMaxWidth(),
                ) { Text(stringResource(R.string.always_allow)) }
                // Reject is an OutlinedButton (not a low-prominence TextButton) in the
                // same column so the actions are visually balanced — the prior layout buried
                // Reject as a small dismiss-button, nudging users toward granting. Reject
                // uses the error color to signal its consequence.
                OutlinedButton(
                    onClick = {
                        haptics.performHapticFeedback(androidx.compose.ui.hapticfeedback.HapticFeedbackType.LongPress)
                        respond(PermissionResponse.REJECT)
                    },
                    modifier = Modifier.fillMaxWidth(),
                ) { Text(stringResource(R.string.reject), color = MaterialTheme.colorScheme.error) }
            }
        },
    )
}