using System.Diagnostics;
using System.Text.RegularExpressions;

namespace FanControl.ChromeboxEC;

/// <summary>ectool 命令封装，参见 docs/ectool-commands-zh.md</summary>
internal static class EctoolRunner
{
    private static readonly Regex NumberRegex = new(@"\d+", RegexOptions.Compiled);

    /// <summary>执行 ectool 命令，返回 (成功, stdout, stderr)</summary>
    public static (bool ok, string stdout, string stderr) Run(
        string exePath,
        IReadOnlyList<string> args,
        int timeoutMs = 15_000)
    {
        if (string.IsNullOrWhiteSpace(exePath) || !File.Exists(exePath))
            return (false, "", "ectool 未找到");

        var psi = new ProcessStartInfo
        {
            FileName = exePath,
            UseShellExecute = false,
            RedirectStandardOutput = true,
            RedirectStandardError = true,
            CreateNoWindow = true,
        };
        foreach (var a in args)
            psi.ArgumentList.Add(a);

        using var proc = new Process { StartInfo = psi };
        try
        {
            proc.Start();
        }
        catch (Exception ex)
        {
            return (false, "", ex.Message);
        }

        var stdout = proc.StandardOutput.ReadToEnd();
        var stderr = proc.StandardError.ReadToEnd();
        if (!proc.WaitForExit(timeoutMs))
        {
            try { proc.Kill(entireProcessTree: true); } catch { /* ignore */ }
            return (false, "", "ectool 超时");
        }

        return (proc.ExitCode == 0, stdout, stderr);
    }

    /// <summary>解析 pwmgetfanrpm 输出中的转速 (500–50000 RPM)</summary>
    public static int? TryParseFanRpm(string stdout)
    {
        if (string.IsNullOrWhiteSpace(stdout))
            return null;

        int? best = null;
        foreach (Match m in NumberRegex.Matches(stdout))
        {
            if (!int.TryParse(m.Value, out var n))
                continue;
            if (n is < 400 or > 50_000)
                continue;
            if (n >= 800 && (best == null || n > best))
                best = n;
        }
        if (best != null)
            return best;

        foreach (Match m in NumberRegex.Matches(stdout))
        {
            if (int.TryParse(m.Value, out var n) && n is >= 400 and <= 50_000)
                return n;
        }
        return null;
    }

    /// <summary>解析 temps 输出为摄氏温度。支持 "329 K (= 56 C)" 等格式，多传感器时取最高值。排除 ratio 行中的 (313 K and 333 K) 等阈值。</summary>
    public static float? TryParseTemp(string stdout)
    {
        if (string.IsNullOrWhiteSpace(stdout))
            return null;

        float? best = null;
        // 匹配 "= 56 C"：最可靠，且不会被 ratio 行的 (313 K and 333 K) 干扰
        foreach (Match m in Regex.Matches(stdout, @"=\s*(\d{1,3})\s*[Cc]\b"))
        {
            if (int.TryParse(m.Groups[1].Value, out var c) && c is >= 0 and <= 120)
            {
                if (best == null || c > best)
                    best = c;
            }
        }
        if (best != null)
            return best;

        // 若无 "= X C"，再匹配 "329 K"，排除 ratio 中的 "313 K and" 与 "and 333 K"
        foreach (Match m in Regex.Matches(stdout, @"(?<!and\s)(\d{2,3})\s*K\b(?!\s+and)", RegexOptions.IgnoreCase))
        {
            if (int.TryParse(m.Groups[1].Value, out var k) && k is >= 250 and <= 400)
            {
                var c = k - 273.15f;
                if (best == null || c > best)
                    best = c;
            }
        }
        return best;
    }
}