package com.pukka.mediaapp.viewmodel

import android.util.Log
import androidx.lifecycle.ViewModel
import androidx.lifecycle.viewModelScope
import com.migu.bean.GetTopButtonBean
import com.pukka.mediaapp.model.LayoutSection
import com.pukka.mediaapp.model.NavItem
import com.pukka.mediaapp.network.MediaRepository
import com.pukka.mediaapp.utils.FileLogger
import kotlinx.coroutines.flow.MutableStateFlow
import kotlinx.coroutines.flow.StateFlow
import kotlinx.coroutines.flow.asStateFlow
import kotlinx.coroutines.launch

/**
 * 首页 ViewModel：负责导航栏数据与二级布局楼层数据。
 */
class HomeViewModel : ViewModel() {

    private val repository = MediaRepository.getInstance()

    private val _navItems = MutableStateFlow<List<NavItem>>(emptyList())
    val navItems: StateFlow<List<NavItem>> = _navItems.asStateFlow()

    private val _sections = MutableStateFlow<List<LayoutSection>>(emptyList())
    val sections: StateFlow<List<LayoutSection>> = _sections.asStateFlow()

    private val _loading = MutableStateFlow(false)
    val loading: StateFlow<Boolean> = _loading.asStateFlow()

    private val _error = MutableStateFlow<String?>(null)
    val error: StateFlow<String?> = _error.asStateFlow()

    /** 默认选中的导航项位置 */
    private val _selectedNavIndex = MutableStateFlow(0)
    val selectedNavIndex: StateFlow<Int> = _selectedNavIndex.asStateFlow()

    private var hasLoadedNav = false

    /** 加载首页导航，加载成功后默认请求 isFocus=1 的导航项对应的布局。 */
    fun loadNav() {
        if (hasLoadedNav) return
        viewModelScope.launch {
            loadTopButton()
            _loading.value = true
            repository.getLayoutNav()
                .onSuccess { response ->
                    val allItems = response.data
                        ?.flatMap { it.navList ?: emptyList() }
                        ?: emptyList()

                    // 只保留有布局数据的标签（type=1 为内容页）
                    val contentItems = allItems.filter { it.type == 1 }
                    _navItems.value = contentItems
                    FileLogger.log("HomeVM", "导航加载: ${contentItems.size} 个标签, 默认选中=${contentItems.indexOfFirst { it.isFocus == "1" }}")
                    hasLoadedNav = true
                    if (contentItems.isNotEmpty()) {
                        // 优先选 isFocus=="1" 的，否则选第一个
                        val defaultIndex = contentItems.indexOfFirst { it.isFocus == "1" }
                        val targetIndex = if (defaultIndex >= 0) defaultIndex else 0
                        _selectedNavIndex.value = targetIndex
                        loadLayout(contentItems[targetIndex].navid)
                    } else {
                        _loading.value = false
                    }
                }
                .onFailure {
                    _error.value = it.message ?: "加载导航失败"
                    _loading.value = false
                }
        }
    }

    /** 根据 navid 加载二级页面布局（楼层列表）。 */
    fun loadLayout(navid: String) {
        if (navid.isEmpty()) return
        viewModelScope.launch {
            _loading.value = true
            repository.getLayout(navid)
                .onSuccess { response ->
                    val sections = response.data ?: emptyList()
                    Log.d("HomeViewModel", "loadLayout success: ${sections.size} sections")
                    FileLogger.log("HomeVM", "布局加载: navid=$navid ${sections.size} 个楼层")
                    _sections.value = sections
                }
                .onFailure {
                    Log.e("HomeViewModel", "loadLayout failed", it)
                    _error.value = it.message ?: "加载内容失败"
                    _sections.value = emptyList()
                }
            _loading.value = false
        }
    }

    /** 顶部功能键数据（供 TopView.bindData 渲染） */
    private val _topButton = MutableStateFlow<GetTopButtonBean?>(null)
    val topButton: StateFlow<GetTopButtonBean?> = _topButton.asStateFlow()

    /** 加载顶部功能键 */
    fun loadTopButton() {
        viewModelScope.launch {
            repository.getTopButton()
                .onSuccess { _topButton.value = it }
                .onFailure { FileLogger.log("HomeVM", "顶部按钮加载失败: ${it.message}") }
        }
    }

    /** 更新选中的导航索引 */
    fun selectNav(index: Int) {
        _selectedNavIndex.value = index
    }
}