#Requires -Version 5.1
# 读写 MySQL 连接配置。仅允许 mysql。

function Get-MesDbConfigPath {
    return (Join-Path $PSScriptRoot "db-config.json")
}

function Get-DefaultMesDbConfig {
    return [ordered]@{
        engine   = "mysql"
        host     = "127.0.0.1"
        port     = 3306
        database = "mes_cloud"
        user     = "mes_cloud"
        password = "s2ENj7KaEySTC7dW"
    }
}

function ConvertTo-MesDbConfig {
    param($InputObject)
    $d = Get-DefaultMesDbConfig
    if ($null -eq $InputObject) { return $d }
    $engine = "mysql"
    if ($InputObject.PSObject.Properties.Name -contains "engine" -and $InputObject.engine) {
        $engine = ([string]$InputObject.engine).Trim().ToLower()
    }
    if ($engine -ne "mysql") {
        throw "仅支持 MySQL，不支持: $engine"
    }
    $hostName = [string]$InputObject.host
    if ([string]::IsNullOrWhiteSpace($hostName)) { $hostName = [string]$d.host }
    $hostName = $hostName.Trim()
    if ($hostName -match "jdbc:mysql://([^:/]+)") {
        $hostName = $Matches[1]
    }
    $hostName = $hostName -replace "^mysql://", ""
    if ($hostName -match "\s|/") {
        throw "IP/主机名不合法"
    }
    $port = [int]$d.port
    if ($InputObject.port) { [void][int]::TryParse([string]$InputObject.port, [ref]$port) }
    if ($port -lt 1 -or $port -gt 65535) { throw "端口必须在 1-65535" }
    $database = [string]$InputObject.database
    if ([string]::IsNullOrWhiteSpace($database)) { $database = [string]$d.database }
    $user = [string]$InputObject.user
    if ([string]::IsNullOrWhiteSpace($user)) { throw "请填写账号" }
    $password = [string]$InputObject.password
    if ($null -eq $password) { $password = "" }
    return [ordered]@{
        engine   = "mysql"
        host     = $hostName.Trim()
        port     = $port
        database = $database.Trim()
        user     = $user.Trim()
        password = $password
    }
}

function Read-MesDbConfig {
    $path = Get-MesDbConfigPath
    if (-not (Test-Path -LiteralPath $path)) {
        $cfg = Get-DefaultMesDbConfig
        Save-MesDbConfig -Config $cfg
        return $cfg
    }
    try {
        $raw = Get-Content -LiteralPath $path -Raw -Encoding UTF8
        if ([string]::IsNullOrWhiteSpace($raw)) { throw "配置文件为空" }
        # 去掉 # 注释行，避免 PowerShell ConvertFrom-Json 报「无效的 JSON 基元」
        $lines = $raw -split "`r?`n" | Where-Object { $_.Trim() -notmatch "^#" }
        $json = ($lines -join "`n").Trim()
        $start = $json.IndexOf("{")
        $end = $json.LastIndexOf("}")
        if ($start -ge 0 -and $end -gt $start) {
            $json = $json.Substring($start, $end - $start + 1)
        }
        $obj = $json | ConvertFrom-Json
        return (ConvertTo-MesDbConfig -InputObject $obj)
    } catch {
        $cfg = Get-DefaultMesDbConfig
        Save-MesDbConfig -Config $cfg
        return $cfg
    }
}

function Save-MesDbConfig {
    param($Config)
    $cfg = ConvertTo-MesDbConfig -InputObject $Config
    $path = Get-MesDbConfigPath
    $json = ($cfg | ConvertTo-Json -Depth 4)
    $utf8 = New-Object System.Text.UTF8Encoding $false
    [System.IO.File]::WriteAllText($path, $json, $utf8)
    return $cfg
}

function Write-MesMysqlCnf {
    param(
        $Config,
        [string]$CnfPath
    )
    $cfg = ConvertTo-MesDbConfig -InputObject $Config
    $pwd = [string]$cfg.password
    $pwd = $pwd.Replace("\", "\\").Replace('"', '\"')
    @(
        "[client]"
        "host=$($cfg.host)"
        "port=$($cfg.port)"
        "user=$($cfg.user)"
        "password=""$pwd"""
        "default-character-set=utf8mb4"
    ) | Set-Content -Path $CnfPath -Encoding ASCII
}