package com.peachpasswords.ui.vault

import androidx.compose.foundation.BorderStroke
import androidx.compose.animation.core.animateDpAsState
import androidx.compose.animation.core.tween
import androidx.compose.foundation.background
import androidx.compose.foundation.border
import androidx.compose.foundation.clickable
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.Spacer
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.offset
import androidx.compose.foundation.layout.navigationBarsPadding
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.statusBarsPadding
import androidx.compose.foundation.layout.width
import androidx.compose.foundation.rememberScrollState
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.foundation.verticalScroll
import androidx.compose.material3.Slider
import androidx.compose.material3.SliderDefaults
import androidx.compose.material3.Surface
import androidx.compose.material3.Text
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.setValue
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.clip
import androidx.compose.ui.draw.clipToBounds
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.text.TextStyle
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.text.input.PasswordVisualTransformation
import androidx.compose.ui.text.input.VisualTransformation
import androidx.compose.ui.text.style.TextAlign
import androidx.compose.ui.text.style.TextOverflow
import androidx.compose.ui.unit.dp
import androidx.compose.ui.unit.em
import androidx.compose.ui.unit.sp
import androidx.compose.runtime.collectAsState
import androidx.hilt.navigation.compose.hiltViewModel
import com.peachpasswords.ui.components.CopyButton
import com.peachpasswords.ui.components.PeachEmptyOrEndState
import com.peachpasswords.ui.components.PeachSegment
import com.peachpasswords.ui.components.PeachSegmentedControl
import com.peachpasswords.ui.components.SecureFlagEffect
import com.peachpasswords.ui.theme.LocalPeachAccent
import com.peachpasswords.ui.theme.PeachMotion
import com.peachpasswords.ui.theme.PeachRadius
import com.peachpasswords.ui.theme.PeachSpacing
import com.peachpasswords.ui.theme.PeachType
import com.peachpasswords.ui.theme.ShellBackground
import com.peachpasswords.ui.theme.peachColors

@Composable
fun EntryEditScreen(
    id: String?,
    onBack: () -> Unit,
    onHome: () -> Unit,
    vm: EntryEditViewModel = hiltViewModel(),
) {
    SecureFlagEffect()

    val f by vm.form.collectAsState()
    val usernameSuggestions by vm.usernameSuggestions.collectAsState()
    val emailSuggestions by vm.emailSuggestions.collectAsState()

    // Ghost watermark fades in (0 → 0.03α over 300ms) once the title has any text.
    val watermarkAlpha by androidx.compose.animation.core.animateFloatAsState(
        targetValue = editGhostWatermarkTarget(f.title),
        animationSpec = tween(300),
        label = "edit-watermark",
    )

    ShellBackground {
        Column(
            Modifier
                .fillMaxSize()
                .statusBarsPadding()
                .padding(horizontal = PeachSpacing.xl),
        ) {
            PeachVaultIdentity(editTitleBarLabel(vm.isNew, f.type), onHome = onHome)

            Spacer(Modifier.height(PeachSpacing.lg))

            Box(Modifier.weight(1f).fillMaxWidth().clipToBounds()) {
                // Ghost Garamond watermark behind the form (matches the detail hero):
                // the full title, fading in as the user types.
                if (watermarkAlpha > 0f) {
                    Text(
                        text = ghostWatermarkText(f.title),
                        style = PeachType.ghostMark.copy(fontSize = 140.sp),
                        color = peachColors.T0.copy(alpha = watermarkAlpha),
                        maxLines = 1,
                        softWrap = false,
                        overflow = androidx.compose.ui.text.style.TextOverflow.Clip,
                        modifier = Modifier.align(Alignment.TopEnd).offset(x = (-16).dp, y = 8.dp),
                    )
                }
                Column(
                    Modifier.fillMaxSize().verticalScroll(rememberScrollState()),
                ) {
                    PeachSegmentedControl(
                        segments = entryEditTypeSegments(),
                        selectedKey = f.type,
                        onSelected = vm::setType,
                    )
                    Spacer(Modifier.height(PeachSpacing.lg))

                    Field("title", f.title, vm::setTitle)
                    if (f.type == "login") {
                        PeachFieldStack {
                            Field(
                                "url", f.url, vm::setUrl,
                                joined = true,
                                divider = true,
                                trailing = if (f.additionalUrls.isEmpty()) {
                                    { AddFieldLink("+ add", vm::addAdditionalUrl) }
                                } else {
                                    null
                                },
                            )
                            if (f.additionalUrls.isNotEmpty()) {
                                AdditionalUrlsEditor(
                                    urls = f.additionalUrls,
                                    onChange = vm::setAdditionalUrl,
                                    onAdd = vm::addAdditionalUrl,
                                    onRemove = vm::removeAdditionalUrl,
                                )
                            }
                            IdentitySuggestField(
                                "username", f.username, usernameSuggestions, vm::setUsername,
                                joined = true,
                                divider = true,
                            )
                            IdentitySuggestField(
                                "email", f.email, emailSuggestions, vm::setEmail,
                                joined = true,
                                divider = true,
                            )
                            PasswordField(
                                value = f.password,
                                show = f.showPassword,
                                generatorOpen = f.generatorOpen,
                                onChange = vm::setPassword,
                                onToggleShow = vm::toggleShowPassword,
                                onToggleGenerator = vm::toggleGenerator,
                                joined = true,
                            )
                        }
                        GeneratorDrawer(
                            open = f.generatorOpen,
                            length = f.genLength,
                            upper = f.genUpper, lower = f.genLower, numbers = f.genNumbers, symbols = f.genSymbols,
                            password = f.password,
                            copied = f.genCopied,
                            onLength = vm::setGenLength,
                            onUpper = vm::setGenUpper, onLower = vm::setGenLower,
                            onNumbers = vm::setGenNumbers, onSymbols = vm::setGenSymbols,
                            onGenerate = vm::generate,
                            onCopy = vm::copyGenerated,
                            onUse = vm::useGeneratedPassword,
                        )
                        PasswordHistorySection(
                            history = f.history,
                            expanded = f.showHistory,
                            onToggle = vm::toggleHistory,
                            onRestore = vm::restorePassword,
                            onCopy = vm::copyHistoryPassword,
                        )
                        OptionalLoginAddLinks(
                            showTotpLink = shouldShowAddTotpLink(f.type, f.showTotp, f.totp),
                            showNotesLink = shouldShowLoginNotesLink(
                                isNew = vm.isNew,
                                type = f.type,
                                revealed = f.showNotes,
                                notes = f.notes,
                            ),
                            onAddTotp = vm::revealTotp,
                            onAddNotes = vm::revealNotes,
                        )
                        if (shouldShowLoginTotp(f.type, f.showTotp, f.totp)) {
                            Field("2FA secret (otpauth:// or base32)", f.totp, vm::setTotp)
                        }
                    }
                    if (f.type == "card") {
                        CardEditFields(
                            cardNickname = f.cardNickname,
                            cardNumber = f.cardNumber,
                            cardholderName = f.cardholderName,
                            expiry = f.expiry,
                            cvc = f.cvc,
                            showCvc = f.showCvc,
                            network = f.cardNetwork,
                            onCardNickname = vm::setCardNickname,
                            onCardNumber = vm::setCardNumber,
                            onCardholder = vm::setCardholderName,
                            onExpiry = vm::setExpiry,
                            onCvc = vm::setCvc,
                            onToggleShowCvc = vm::toggleShowCvc,
                        )
                    }
                    if (f.type == "note" || shouldShowLoginNotes(f.type, f.showNotes, f.notes)) {
                        Field("notes", f.notes, vm::setNotes, singleLine = false)
                    }
                    if (f.type == "login") {
                        CanaryEditSection(
                            entryId = id ?: "new",
                            modifiedAt = f.canary?.lastPinged ?: 0L,
                            canary = f.canary,
                            isPro = vm.isPro,
                            message = f.canaryMessage,
                            testing = f.canaryTesting,
                            onSave = vm::setCanary,
                            onTest = vm::testCanary,
                        )
                    }
                    TagChipEditor(
                        tags = f.tags,
                        allTags = vm.allTags,
                        onAdd = vm::addTag,
                        onRemove = vm::removeTag,
                    )

                    f.error?.let {
                        Spacer(Modifier.height(PeachSpacing.sm))
                        Text(it, color = peachColors.Breach, fontFamily = PeachType.Mono, fontSize = 11.sp)
                    }
                    Spacer(Modifier.height(PeachSpacing.xl))
                }
            }
            EntryEditBottomActions(
                saveLabel = entryEditPrimaryActionLabel(vm.isNew, f.saving),
                canSave = canSaveEditForm(f) && !f.saving,
                onCancel = onBack,
                onSave = { vm.save(onBack) },
            )
        }
    }
}

@Composable
private fun EntryEditBottomActions(
    saveLabel: String,
    canSave: Boolean,
    onCancel: () -> Unit,
    onSave: () -> Unit,
) {
    val accent = LocalPeachAccent.current
    Row(
        Modifier.fillMaxWidth().navigationBarsPadding().padding(vertical = PeachSpacing.md),
        horizontalArrangement = Arrangement.spacedBy(PeachSpacing.md),
    ) {
        Surface(
            modifier = Modifier.weight(1f).clickable(onClick = onCancel),
            color = peachColors.S1,
            shape = RoundedCornerShape(PeachRadius.StackCard),
            border = BorderStroke(1.dp, peachColors.T3),
        ) {
            Text("cancel", color = peachColors.T1, style = PeachType.bodyMono, modifier = Modifier.padding(18.dp), textAlign = TextAlign.Center)
        }
        Surface(
            modifier = Modifier.weight(1f).clickable(enabled = canSave, onClick = onSave),
            color = if (canSave) accent else peachColors.S2,
            shape = RoundedCornerShape(PeachRadius.StackCard),
        ) {
            Text(saveLabel, color = if (canSave) peachColors.Bg else peachColors.T2, style = PeachType.bodyMono, modifier = Modifier.padding(18.dp), textAlign = TextAlign.Center)
        }
    }
}

/** Centered title-bar label: "new entry" / "new note" / "new card", or "edit". */
internal fun editTitleBarLabel(isNew: Boolean, type: String): String = when {
    !isNew -> "edit"
    type == "note" -> "new note"
    type == "card" -> "new card"
    else -> "new entry"
}

internal fun entryEditTypeSegments(): List<PeachSegment> = listOf(
    PeachSegment("login", "login"),
    PeachSegment("card", "card"),
)

internal fun entryEditPrimaryActionLabel(isNew: Boolean, saving: Boolean): String = when {
    saving -> "saving..."
    isNew -> "create"
    else -> "save"
}

internal fun canSaveEditForm(form: EditForm): Boolean {
    if (form.title.isBlank()) return false
    if (form.type == "card" && (form.cardholderName.isBlank() || form.cardNumber.isBlank())) return false
    return true
}

/** Target alpha for the edit-screen ghost watermark — visible only once a title exists. */
internal fun editGhostWatermarkTarget(title: String): Float = if (title.isNotBlank()) 0.03f else 0f

internal fun shouldShowLoginTotp(type: String, revealed: Boolean, totp: String): Boolean =
    type == "login" && (revealed || totp.isNotBlank())

internal fun shouldShowLoginNotes(type: String, revealed: Boolean, notes: String): Boolean =
    type == "login" && (revealed || notes.isNotBlank())

internal fun shouldShowAddTotpLink(type: String, revealed: Boolean, totp: String): Boolean =
    type == "login" && !shouldShowLoginTotp(type, revealed, totp)

internal fun shouldShowAddNotesLink(type: String, revealed: Boolean, notes: String): Boolean =
    type == "login" && !shouldShowLoginNotes(type, revealed, notes)

internal fun shouldShowLoginNotesLink(isNew: Boolean, type: String, revealed: Boolean, notes: String): Boolean =
    !isNew && shouldShowAddNotesLink(type, revealed, notes)

@Composable
private fun OptionalLoginAddLinks(
    showTotpLink: Boolean,
    showNotesLink: Boolean,
    onAddTotp: () -> Unit,
    onAddNotes: () -> Unit,
) {
    if (!showTotpLink && !showNotesLink) return
    PeachFieldStack {
        Text(
            "OPTIONAL FIELDS",
            color = peachColors.T2,
            fontFamily = PeachType.Mono,
            fontSize = 8.sp,
            letterSpacing = 0.08.em,
            modifier = Modifier.padding(start = PeachSpacing.lg, top = PeachSpacing.md),
        )
        Row(
            Modifier.fillMaxWidth().padding(horizontal = PeachSpacing.lg, vertical = PeachSpacing.sm),
            horizontalArrangement = Arrangement.spacedBy(14.dp),
        ) {
            if (showTotpLink) AddFieldLink("+ add 2FA", onAddTotp)
            if (showNotesLink) AddFieldLink("+ add notes", onAddNotes)
        }
    }
}

@Composable
private fun AddFieldLink(label: String, onClick: () -> Unit) {
    Text(
        label,
        color = LocalPeachAccent.current,
        fontFamily = PeachType.Mono,
        fontSize = 11.sp,
        modifier = Modifier.clip(RoundedCornerShape(6.dp)).clickable(onClick = onClick).padding(vertical = 6.dp),
    )
}

@Composable
private fun Field(
    label: String,
    value: String,
    onChange: (String) -> Unit,
    singleLine: Boolean = true,
    transformation: VisualTransformation = VisualTransformation.None,
    trailing: (@Composable () -> Unit)? = null,
    joined: Boolean = false,
    divider: Boolean = false,
) {
    PeachField(
        label = label,
        value = value,
        onChange = onChange,
        singleLine = singleLine,
        mono = true,
        visualTransformation = transformation,
        trailing = trailing,
        joined = joined,
        divider = divider,
    )
}

@Composable
private fun PasswordField(
    value: String,
    show: Boolean,
    generatorOpen: Boolean,
    onChange: (String) -> Unit,
    onToggleShow: () -> Unit,
    onToggleGenerator: () -> Unit,
    joined: Boolean = false,
    divider: Boolean = false,
) {
    Field(
        label = "password",
        value = value,
        onChange = onChange,
        transformation = if (show) VisualTransformation.None else PasswordVisualTransformation(),
        joined = joined,
        divider = divider,
        trailing = {
            Row(horizontalArrangement = Arrangement.spacedBy(6.dp)) {
                PasswordAction(if (show) "hide" else "show", onToggleShow)
                PasswordAction(generatorToggleLabel(generatorOpen), onToggleGenerator)
            }
        },
    )
}

@Composable
private fun PasswordAction(label: String, onClick: () -> Unit) {
    val accent = LocalPeachAccent.current
    Text(
        label,
        color = accent,
        fontFamily = PeachType.Mono,
        fontSize = 9.sp,
        modifier = Modifier
            .clip(RoundedCornerShape(6.dp))
            .background(accent.copy(alpha = 0.08f))
            .clickable(onClick = onClick)
            .padding(horizontal = 7.dp, vertical = 5.dp),
    )
}

internal fun generatorToggleLabel(open: Boolean): String = if (open) "hide generator" else "generate"

@Composable
private fun GeneratorDrawer(
    open: Boolean,
    length: Int,
    upper: Boolean, lower: Boolean, numbers: Boolean, symbols: Boolean,
    password: String,
    copied: Boolean,
    onLength: (Int) -> Unit,
    onUpper: (Boolean) -> Unit, onLower: (Boolean) -> Unit,
    onNumbers: (Boolean) -> Unit, onSymbols: (Boolean) -> Unit,
    onGenerate: () -> Unit,
    onCopy: () -> Unit,
    onUse: () -> Unit,
) {
    val height by animateDpAsState(
        targetValue = if (open) 326.dp else 0.dp,
        animationSpec = tween(320, easing = PeachMotion.Spring),
        label = "gen-drawer",
    )
    Box(
        Modifier.fillMaxWidth().height(height).clipToBounds()
            .clip(RoundedCornerShape(12.dp))
            .background(peachColors.S2)
            .border(1.dp, peachColors.T3, RoundedCornerShape(12.dp)),
    ) {
        GeneratorBody(
            length = length,
            upper = upper, lower = lower, numbers = numbers, symbols = symbols,
            password = password, copied = copied,
            onLength = onLength,
            onUpper = onUpper, onLower = onLower, onNumbers = onNumbers, onSymbols = onSymbols,
            onGenerate = onGenerate, onCopy = onCopy,
            showOutput = true,
            onUse = onUse,
        )
    }
    if (open) Spacer(Modifier.height(14.dp))
}

/**
 * Shared generator body — used by the inline drawer here and the detail
 * ModalBottomSheet (D4). Stateless; the generate row carries the [Copy] drain.
 */
@Composable
internal fun GeneratorBody(
    length: Int,
    upper: Boolean, lower: Boolean, numbers: Boolean, symbols: Boolean,
    password: String,
    copied: Boolean,
    onLength: (Int) -> Unit,
    onUpper: (Boolean) -> Unit, onLower: (Boolean) -> Unit,
    onNumbers: (Boolean) -> Unit, onSymbols: (Boolean) -> Unit,
    onGenerate: () -> Unit,
    onCopy: () -> Unit,
    showOutput: Boolean = false,
    onUse: (() -> Unit)? = null,
) {
    val accent = LocalPeachAccent.current
    Column(Modifier.fillMaxWidth().padding(16.dp)) {
        if (showOutput) {
            Box(
                Modifier.fillMaxWidth().clip(RoundedCornerShape(10.dp))
                    .border(1.dp, accent.copy(alpha = 0.45f), RoundedCornerShape(10.dp))
                    .background(accent.copy(alpha = 0.08f))
                    .padding(horizontal = 12.dp, vertical = 10.dp),
            ) {
                Text(
                    text = password.ifEmpty { "tap generate" },
                    color = if (password.isEmpty()) peachColors.T2 else peachColors.T0,
                    fontFamily = PeachType.Mono,
                    fontSize = 11.sp,
                    maxLines = 2,
                    overflow = TextOverflow.Ellipsis,
                )
            }
            Spacer(Modifier.height(10.dp))
        }
        Row(Modifier.fillMaxWidth(), horizontalArrangement = Arrangement.SpaceBetween) {
            Text("GENERATOR", color = peachColors.T1, fontFamily = PeachType.Mono, fontSize = 8.sp)
            Text("length $length", color = accent, fontFamily = PeachType.Mono, fontSize = 9.sp)
        }
        Slider(
            value = length.toFloat(),
            onValueChange = { onLength(it.toInt()) },
            valueRange = 8f..128f,
            colors = SliderDefaults.colors(
                thumbColor = accent, activeTrackColor = accent, inactiveTrackColor = peachColors.T3,
            ),
        )
        Row(horizontalArrangement = Arrangement.spacedBy(8.dp)) {
            TogglePill("A-Z", upper, onUpper)
            TogglePill("a-z", lower, onLower)
            TogglePill("0-9", numbers, onNumbers)
            TogglePill("!@#", symbols, onSymbols)
        }
        Spacer(Modifier.height(12.dp))
        Row(verticalAlignment = Alignment.CenterVertically) {
            Box(
                Modifier.weight(1f).clip(RoundedCornerShape(10.dp))
                    .border(1.dp, accent.copy(alpha = 0.5f), RoundedCornerShape(10.dp))
                    .background(accent.copy(alpha = 0.10f))
                    .clickable(onClick = onGenerate).padding(vertical = 12.dp),
                contentAlignment = Alignment.Center,
            ) {
                Text(if (password.isEmpty()) "generate" else "regenerate", color = accent, fontFamily = PeachType.Mono, fontSize = 12.sp)
            }
            Spacer(Modifier.width(8.dp))
            CopyButton(copied = copied, onCopy = { if (password.isNotEmpty()) onCopy() })
        }
        onUse?.let {
            Spacer(Modifier.height(10.dp))
            Box(
                Modifier.fillMaxWidth().clip(RoundedCornerShape(10.dp))
                    .border(1.dp, accent.copy(alpha = 0.5f), RoundedCornerShape(10.dp))
                    .background(accent.copy(alpha = 0.14f))
                    .clickable(enabled = password.isNotEmpty(), onClick = it)
                    .padding(vertical = 12.dp),
                contentAlignment = Alignment.Center,
            ) {
                Text("use", color = if (password.isEmpty()) accent.copy(alpha = 0.45f) else accent, fontFamily = PeachType.Mono, fontSize = 12.sp)
            }
        }
    }
}

@Composable
private fun TogglePill(label: String, on: Boolean, onToggle: (Boolean) -> Unit) {
    val accent = LocalPeachAccent.current
    Box(
        Modifier.clip(RoundedCornerShape(PeachRadius.TypeTab))
            .border(1.dp, if (on) accent.copy(alpha = 0.5f) else peachColors.T3, RoundedCornerShape(PeachRadius.TypeTab))
            .background(if (on) accent.copy(alpha = 0.10f) else Color.Transparent)
            .clickable { onToggle(!on) }
            .padding(horizontal = 10.dp, vertical = 6.dp),
    ) {
        Text(label, color = if (on) accent else peachColors.T2, fontFamily = PeachType.Mono, fontSize = 9.sp)
    }
}

// PasswordHistorySection / HistoryRow / HistoryAction / timeSince were extracted
// to ui/vault/PasswordHistorySection.kt (D7) so EntryDetailScreen can reuse them.