package com.suno.android.ui.screens.onboarding.login

import android.net.Uri
import androidx.compose.foundation.background
import androidx.compose.foundation.gestures.detectTapGestures
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.size
import androidx.compose.material3.Text
import androidx.compose.runtime.Composable
import androidx.compose.runtime.LaunchedEffect
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.input.pointer.pointerInput
import androidx.compose.ui.res.stringResource
import androidx.compose.ui.text.SpanStyle
import androidx.compose.ui.text.TextLayoutResult
import androidx.compose.ui.text.buildAnnotatedString
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.text.style.TextAlign
import androidx.compose.ui.unit.dp
import androidx.hilt.navigation.compose.hiltViewModel
import androidx.lifecycle.compose.collectAsStateWithLifecycle
import com.suno.android.common_ui.components.buttons.AuthenticationOption
import com.suno.android.common_ui.components.loading.SunoSpinner
import com.suno.android.common_ui.theme.ExtendedTheme
import com.suno.android.common_res.R as CommonResR

@Composable
fun LoginScreen(
    vm: LoginScreenVM = hiltViewModel(),
    onOauth: (Boolean, Uri) -> Unit,
    onPhoneAuthClicked: (Boolean) -> Unit,
    onTermsClicked: () -> Unit,
    onPrivacyPolicyClicked: () -> Unit,
) {
    LaunchedEffect(Unit) {
        vm.effects.collect { effect ->
            when (effect) {
                is LoginScreenEffect.OnOauthClicked -> {
                    onOauth.invoke(effect.isSignUp, effect.redirectUrl)
                }

                is LoginScreenEffect.OnPhoneNumberClicked -> {
                    onPhoneAuthClicked.invoke(effect.isSignUp)
                }
            }
        }
    }

    val viewState = vm.state.collectAsStateWithLifecycle().value
    val authLoading = viewState.authLoading

    Column(
        modifier = Modifier
            .background(ExtendedTheme.colors.backgroundPrimary)
            .fillMaxSize()
            .padding(32.dp),
        horizontalAlignment = Alignment.CenterHorizontally,
        verticalArrangement = Arrangement.SpaceEvenly,
    ) {
        Text(
            text = if (viewState.isSignUp) {
                stringResource(CommonResR.string.sign_up_title)
            } else {
                stringResource(CommonResR.string.log_in_to_suno)
            },
            textAlign = TextAlign.Center,
            style = ExtendedTheme.typography.largeHeadline,
            color = ExtendedTheme.colors.textPrimary,
        )

        Text(
            text = if (viewState.isSignUp) {
                stringResource(CommonResR.string.sign_up_subtitle)
            } else {
                stringResource(CommonResR.string.or_create_free_account)
            },
            style = ExtendedTheme.typography.body,
            color = ExtendedTheme.colors.textPrimary,
        )

        Column(
            verticalArrangement = Arrangement.spacedBy(8.dp),
        ) {
            viewState.authenticationOptions.forEach {
                AuthenticationOption(
                    imageIcon = it.imageRes,
                    displayOptionText = stringResource(it.textRes),
                    onClick = {
                        vm.sendEvent(it.loginMethodEvent)
                    },
                )
            }
        }

        val termsText = stringResource(CommonResR.string.terms_of_service)
        val privacyText = stringResource(CommonResR.string.privacy_policy)

        val formattedText = stringResource(
            CommonResR.string.terms_and_privacy_agreement,
            termsText,
            privacyText,
        )

        val annotatedString = buildAnnotatedString {
            val termsStart = formattedText.indexOf(termsText)
            val termsEnd = termsStart + termsText.length
            val privacyStart = formattedText.indexOf(privacyText)
            val privacyEnd = privacyStart + privacyText.length

            append(formattedText)

            addStringAnnotation(
                tag = "TERMS",
                annotation = "terms",
                start = termsStart,
                end = termsEnd,
            )
            addStyle(
                style = SpanStyle(
                    color = ExtendedTheme.colors.sunoPink,
                    fontWeight = FontWeight.Bold,
                ),
                start = termsStart,
                end = termsEnd,
            )

            addStringAnnotation(
                tag = "PRIVACY",
                annotation = "privacy",
                start = privacyStart,
                end = privacyEnd,
            )
            addStyle(
                style = SpanStyle(
                    color = ExtendedTheme.colors.sunoPink,
                    fontWeight = FontWeight.Bold,
                ),
                start = privacyStart,
                end = privacyEnd,
            )
        }

        var layoutResult: TextLayoutResult? = null

        Text(
            modifier = Modifier
                .fillMaxWidth()
                .pointerInput(Unit) {
                    detectTapGestures { tapOffset ->
                        layoutResult?.let { textLayoutResult ->
                            val position = textLayoutResult.getOffsetForPosition(tapOffset)
                            annotatedString.getStringAnnotations(start = position, end = position).firstOrNull()
                                ?.let { annotation ->
                                    when (annotation.tag) {
                                        "TERMS" -> {
                                            if (!authLoading) {
                                                onTermsClicked()
                                            }
                                        }

                                        "PRIVACY" -> {
                                            if (!authLoading) {
                                                onPrivacyPolicyClicked()
                                            }
                                        }
                                    }
                                }
                        }
                    }
                },
            onTextLayout = { layoutResult = it },
            text = annotatedString,
            style = ExtendedTheme.typography.smallBody,
            textAlign = TextAlign.Center,
            color = ExtendedTheme.colors.textPrimary,
        )
    }

    if (authLoading) {
        Box(
            modifier = Modifier
                .background(color = Color.Black.copy(alpha = 0.5f))
                .fillMaxSize(),
            contentAlignment = Alignment.Center,
        ) {
            SunoSpinner(
                modifier = Modifier.size(64.dp),
            )
        }
    }
}