package providers

import (
	"bufio"
	"fmt"
	"os"
	"os/exec"
	"path"
	"regexp"
	"strconv"
	"strings"
	"time"
)

var id, prettyName string

func GetDist() (string, string) {
	f, _ := os.Open("/etc/os-release")
	defer func(f *os.File) {
		err := f.Close()
		if err != nil {
			fmt.Println("Error closing file:", err)
		}
	}(f)
	s := bufio.NewScanner(f)
	for s.Scan() {
		t := s.Text()
		if strings.HasPrefix(t, "ID=") {
			id = strings.TrimPrefix(t, "ID=")
		}
		if strings.HasPrefix(t, "PRETTY_NAME=") {
			prettyName = strings.TrimPrefix(t, "PRETTY_NAME=")
			prettyName = strings.Trim(prettyName, "\"")
		}
	}
	if id == "" && prettyName == "" {
		return "unknown", "unknown"
	}
	return id, prettyName
}

func GetRam() string {
	f, err := os.Open("/proc/meminfo")
	if err != nil {
		return "error"
	}

	var total, available int
	s := bufio.NewScanner(f)
	for s.Scan() {
		line := s.Text()
		if strings.HasPrefix(line, "MemTotal:") {
			_, err2 := fmt.Sscanf(line, "MemTotal: %d kB", &total)
			if err2 != nil {
				return ""
			}
		}
		if strings.HasPrefix(line, "MemAvailable:") {
			_, err := fmt.Sscanf(line, "MemAvailable: %d kB", &available)
			if err != nil {
				return ""
			}
		}
	}
	totalMB := total / 1024
	availableMB := available / 1024
	usedMB := totalMB - availableMB

	ram := fmt.Sprintf("%d / %d MiB", usedMB, totalMB)
	ram = strings.TrimSpace(ram)
	return ram

}

func GetCpu() string {
	f, err := os.Open("/proc/cpuinfo")
	if err != nil {
		return "unknown"
	}

	var cpu string
	s := bufio.NewScanner(f)
	for s.Scan() {
		line := s.Text()
		if strings.HasPrefix(line, "model name") {
			parts := strings.SplitN(line, ":", 2)
			if len(parts) > 1 {
				cpu := strings.TrimSpace(parts[1])
				return cpu
			}
		}
	}

	return strings.TrimSpace(cpu)
}

func GetGpu() string {
	out, err := exec.Command("sh", "-c", `lspci -mm | awk -F'"' '$2=="VGA compatible controller" || $2=="3D controller" || $2=="Display controller"'`).Output()
	if err != nil || len(out) == 0 {
		return "unknown GPU"
	}

	lines := strings.Split(strings.TrimSpace(string(out)), "\n")
	var gpus []string

	for _, line := range lines {
		re := regexp.MustCompile(`"([^"]+)"`)
		matches := re.FindAllStringSubmatch(line, -1)

		if len(matches) >= 3 {
			vendor := matches[1][1]
			device := matches[2][1]

			cleaned := cleanGpuString(vendor + " " + device)
			gpus = append(gpus, cleaned)
		}
	}

	if len(gpus) > 0 {
		return strings.Join(gpus, " / ")
	}
	return "GPU not found"
}

func cleanGpuString(raw string) string {
	prettyNameRe := regexp.MustCompile(`\[(.*?)]`)
	match := prettyNameRe.FindStringSubmatch(raw)

	res := raw
	if len(match) > 1 {
		vendor := ""
		if strings.Contains(strings.ToLower(raw), "nvidia") {
			vendor = "NVIDIA "
		}
		if strings.Contains(strings.ToLower(raw), "intel") {
			vendor = "Intel "
		}
		if strings.Contains(strings.ToLower(raw), "amd") {
			vendor = "AMD "
		}

		res = vendor + match[1]
	}

	re := regexp.MustCompile(`\(.*?\)|\[.*?]`)
	res = re.ReplaceAllString(res, "")

	fluff := []string{"Corporation", "Controller", "VGA compatible", "3D", "Graphics", "Device"}
	for _, word := range fluff {
		res = strings.ReplaceAll(res, word, "")
	}

	return strings.Join(strings.Fields(res), " ")
}

func GetKernel() string {
	out, err := os.ReadFile("/proc/version")
	if err != nil {
		return "unknown"
	}
	str := strings.TrimSpace(string(out))
	str = strings.ReplaceAll(str, " version ", " ")
	if idx := strings.Index(str, "("); idx != -1 {
		str = str[:idx]
	}
	return strings.TrimSpace(str)
}

func GetHostname() string {
	hostname, err := os.ReadFile("/etc/hostname")
	if err != nil {
		return "unknown"
	}
	username := os.Getenv("USER")
	if username == "" {
		username = os.Getenv("LOGNAME")
	}
	if username == "" {
		return "unknown"
	}
	return fmt.Sprintf("%s@%s", username, strings.TrimSpace(string(hostname)))
}

func GetTerminal() string {
	shellPID := os.Getppid()
	out, err := exec.Command("ps", "-p", fmt.Sprint(shellPID), "-o", "ppid=").Output()
	if err != nil {
		return os.Getenv("TERM")
	}

	terminalPID := strings.TrimSpace(string(out))
	nameOut, err := exec.Command("ps", "-p", terminalPID, "-o", "comm=").Output()
	if err != nil {
		return os.Getenv("TERM")
	}
	// those subprocess ARE NOT SLOWING DOWN THE FETCH MELVI, execution time is the same, you can check it

	return strings.TrimSpace(string(nameOut))
}

func GetDE() string {
	de := os.Getenv("XDG_CURRENT_DESKTOP")
	if de == "" {
		return "unknown or w/o GUI"
	}
	return strings.TrimSpace(de)
}

func GetUptime() string {
	data, err := os.ReadFile("/proc/uptime")
	if err != nil {
		return "0"
	}
	uptimeStr := strings.Fields(string(data))[0]
	seconds, err := strconv.ParseFloat(uptimeStr, 64)
	if err != nil {
		_, err := fmt.Fprintf(os.Stderr, "Error: %v\n", err)
		if err != nil {
			return "error printing uptime"
		}
		return ""
	}
	d := time.Duration(seconds) * time.Second
	formatted := d.Round(time.Second).String()
	spaced := strings.NewReplacer("h", "h ", "m", "m ", "s", "s ").Replace(formatted)
	return spaced
}

func GetShell() string {
	out, err := exec.Command("ps", "-p", strconv.Itoa(os.Getppid()), "-o", "comm=").Output()
	if err != nil {
		return path.Base(os.Getenv("SHELL"))
	}
	return strings.TrimSpace(string(out))
}

func GetAge() string {
	out, err := exec.Command("stat", "-c", "%W", "/").Output()
	if err != nil {
		fmt.Printf("Error executing command: %v\n", err)
		return "unknown"
	}
	birthTime := strings.TrimSpace(string(out))
	if birthTime == "0" || birthTime == "-" {
		return "unknown"
	}
	age, _ := strconv.Atoi(birthTime)
	age = int(time.Now().Unix() - int64(age))
	birth := age / 86400
	return fmt.Sprintf("%d days", birth)
}