package common

import (
	"os"
	"os/exec"
	"path/filepath"
	"runtime"
	"strconv"
	"strings"
)

func PathExists(path string) bool {
	_, err := os.Stat(path)
	return err == nil
}

func ExecCmd(cmd string) (string, error) {
	var c *exec.Cmd
	c = exec.Command("/bin/sh", "-c", cmd)
	out, err := c.CombinedOutput()
	return string(out), err
}

func RunCmd(cmd string, shell bool) ([]byte, error) {
	if shell {
		out, err := exec.Command("bash", "-c", cmd).CombinedOutput()
		return out, err
	} else {
		out, err := exec.Command(cmd).CombinedOutput()
		return out, err
	}
}

func GetCurrentFileDir() string {
	_, file, _, _ := runtime.Caller(1)
	return filepath.Dir(file)
}

func ReadLink(path string) string {
	info, err := os.Lstat(path)
	if err != nil {
		return path
	}
	if strings.HasPrefix(info.Mode().String(), "L") {
		dstPath, err := os.Readlink(path)
		if err != nil {
			return path
		}
		if strings.HasPrefix(dstPath, "/") {
			return dstPath
		}
		absDstPath := filepath.Join(filepath.Dir(path), dstPath)
		return absDstPath
	}
	return path
}

// return whether s exists in sList
func InStringList(s string, sList []string) bool {
	for _, str := range sList {
		if len(s) == len(str) && s == str {
			return true
		}
	}
	return false
}

func InIntList(i int, iList []int) bool {
	for _, num := range iList {
		if i == num {
			return true
		}
	}
	return false
}

func InUintList(i uint, iList []uint) bool {
	for _, num := range iList {
		if i == num {
			return true
		}
	}
	return false
}

func CreateIfNotExistDir(dir string) error {
	if PathExists(dir) {
		return nil
	}
	return os.MkdirAll(dir, 0700)
}

// version_compare()
// The possible operators are: <, lt, <=, le, >, gt, >=, ge, ==, =, eq, !=, <>, ne respectively.
// special version strings these are handled in the following order,
// (any string not found) < dev < alpha = a < beta = b < RC = rc < # < pl = p
// Usage:
// VersionCompare("1.2.3-alpha", "1.2.3RC7", '>=')
// VersionCompare("1.2.3-beta", "1.2.3pl", 'lt')
// VersionCompare("1.1_dev", "1.2any", 'eq')
func VersionCompare(version1, version2, operator string) bool {
	var vcompare func(string, string) int
	var canonicalize func(string) string
	var special func(string, string) int

	// version compare
	vcompare = func(origV1, origV2 string) int {
		if origV1 == "" || origV2 == "" {
			if origV1 == "" && origV2 == "" {
				return 0
			} else {
				if origV1 == "" {
					return -1
				} else {
					return 1
				}
			}
		}
		if (origV1 == "*" || origV2 == "*") && (operator == "eq" ||
			operator == "=" || operator == "==") {
			return 0
		}

		ver1, ver2, compare := "", "", 0
		if origV1[0] == '#' {
			ver1 = origV1
		} else {
			ver1 = canonicalize(origV1)
		}
		if origV2[0] == '#' {
			ver2 = origV2
		} else {
			ver2 = canonicalize(origV2)
		}
		n1, n2 := 0, 0
		for {
			p1, p2 := "", ""
			n1 = strings.IndexByte(ver1, '.')
			if n1 == -1 {
				p1, ver1 = ver1, ""
			} else {
				p1, ver1 = ver1[:n1], ver1[n1+1:]
			}
			n2 = strings.IndexByte(ver2, '.')
			if n2 == -1 {
				p2, ver2 = ver2, ""
			} else {
				p2, ver2 = ver2[:n2], ver2[n2+1:]
			}
			if (p1[0] >= '0' && p1[0] <= '9') && (p2[0] >= '0' && p2[0] <= '9') { // all isdigit
				l1, _ := strconv.Atoi(p1)
				l2, _ := strconv.Atoi(p2)
				if l1 > l2 {
					compare = 1
				} else if l1 == l2 {
					compare = 0
				} else {
					compare = -1
				}
			} else if !(p1[0] >= '0' && p1[0] <= '9') && !(p2[0] >= '0' && p2[0] <= '9') { // all isndigit
				compare = special(p1, p2)
			} else { // part isdigit
				if p1[0] >= '0' && p1[0] <= '9' { // isdigit
					compare = special("#N#", p2)
				} else {
					compare = special(p1, "#N#")
				}
			}
			if compare != 0 || n1 == -1 || n2 == -1 {
				break
			}
		}

		if compare == 0 {
			if ver1 != "" {
				if ver1[0] >= '0' && ver1[0] <= '9' {
					compare = 1
				} else {
					compare = vcompare(ver1, "#N#")
				}
			} else if ver2 != "" {
				if ver2[0] >= '0' && ver2[0] <= '9' {
					compare = -1
				} else {
					compare = vcompare("#N#", ver2)
				}
			}
		}

		return compare
	}

	// canonicalize
	canonicalize = func(version string) string {
		ver := []byte(version)
		l := len(ver)
		if l == 0 {
			return ""
		}
		var buf = make([]byte, l*2)
		j := 0
		for i, v := range ver {
			next := uint8(0)
			if i+1 < l { // Have the next one
				next = ver[i+1]
			}
			if v == '-' || v == '_' || v == '+' { // repalce "-","_","+" to "."
				if j > 0 && buf[j-1] != '.' {
					buf[j] = '.'
					j++
				}
			} else if (next > 0) &&
				(!(next >= '0' && next <= '9') && (v >= '0' && v <= '9')) ||
				(!(v >= '0' && v <= '9') && (next >= '0' && next <= '9')) { // Insert '.' before and after a non-digit
				buf[j] = v
				j++
				if v != '.' && next != '.' {
					buf[j] = '.'
					j++
				}
				continue
			} else if !((v >= '0' && v <= '9') ||
				(v >= 'a' && v <= 'z') || (v >= 'A' && v <= 'Z')) { // Non-letters and numbers
				if j > 0 && buf[j-1] != '.' {
					buf[j] = '.'
					j++
				}
			} else {
				buf[j] = v
				j++
			}
		}

		return string(buf[:j])
	}

	//compare special version forms
	special = func(form1, form2 string) int {
		found1, found2, len1, len2 := -1, -1, len(form1), len(form2)
		// (Any string not found) < dev < alpha = a < beta = b < RC = rc < # < pl = p
		forms := map[string]int{
			"dev":   0,
			"alpha": 1,
			"a":     1,
			"beta":  2,
			"b":     2,
			"RC":    3,
			"rc":    3,
			"#":     4,
			"pl":    5,
			"p":     5,
		}

		for name, order := range forms {
			if len1 < len(name) {
				continue
			}
			if strings.Compare(form1[:len(name)], name) == 0 {
				found1 = order
				break
			}
		}
		for name, order := range forms {
			if len2 < len(name) {
				continue
			}
			if strings.Compare(form2[:len(name)], name) == 0 {
				found2 = order
				break
			}
		}

		if found1 == found2 {
			return 0
		} else if found1 > found2 {
			return 1
		} else {
			return -1
		}
	}

	var compare int
	// <> means between, version2 is a comma seperated version, eg: 1.2,2.0 means
	// vesion1 > 1.2 and version1 < 2.0
	if operator == "<>" {
		splits := strings.Split(version2, ",")
		if len(splits) != 2 {
			return false
		}
		return VersionCompare(version1, splits[0], ">") && VersionCompare(version1,
			splits[1], "<")
	} else {
		compare = vcompare(version1, version2)
	}

	switch operator {
	case "<", "lt":
		return compare == -1
	case "<=", "le":
		return compare != 1
	case ">", "gt":
		return compare == 1
	case ">=", "ge":
		return compare != -1
	case "==", "=", "eq":
		return compare == 0
	case "!=", "ne":
		return compare != 0
	default:
		//panic("operator: invalid")
		return false
	}
}