YDLPreconditions.kt

package com.ydl.ydlcommon.utils

/**
 * Created by haorui on 2019-08-22 .
 * Des: 前置条件判断工具类
 */
class YDLPreconditions private constructor() {

    init {
        throw IllegalStateException("you can't instantiate me!")
    }

    companion object {

        fun checkArgument(expression: Boolean) {
            if (!expression) {
                throw IllegalArgumentException()
            }
        }

        fun checkArgument(expression: Boolean, errorMessage: Any?) {
            if (!expression) {
                throw IllegalArgumentException(errorMessage.toString())
            }
        }

        fun checkArgument(expression: Boolean, errorMessageTemplate: String, vararg errorMessageArgs: Any) {
            if (!expression) {
                throw IllegalArgumentException(
                    format(
                        errorMessageTemplate,
                        *errorMessageArgs
                    )
                )
            }
        }

        fun checkState(expression: Boolean) {
            if (!expression) {
                throw IllegalStateException()
            }
        }

        fun checkState(expression: Boolean, errorMessage: Any?) {
            if (!expression) {
                throw IllegalStateException(errorMessage.toString())
            }
        }

        fun checkState(expression: Boolean, errorMessageTemplate: String, vararg errorMessageArgs: Any) {
            if (!expression) {
                throw IllegalStateException(
                    format(
                        errorMessageTemplate,
                        *errorMessageArgs
                    )
                )
            }
        }

        fun <T> checkNotNull(reference: T?): T {
            return if (reference == null) {
                throw NullPointerException()
            } else {
                reference
            }
        }

        fun <T> checkNotNull(reference: T?, errorMessage: Any?): T {
            return reference ?: throw NullPointerException(errorMessage.toString())
        }

        fun <T> checkNotNull(reference: T?, errorMessageTemplate: String, vararg errorMessageArgs: Any): T {
            return reference ?: throw NullPointerException(
                format(
                    errorMessageTemplate,
                    *errorMessageArgs
                )
            )
        }

        fun checkEmpty(reference: String?, errorMessageTemplate: String, vararg errorMessageArgs: Any){
            reference?.isEmpty() ?: throw NullPointerException(
                format(
                    errorMessageTemplate,
                    *errorMessageArgs
                )
            )
        }

        @JvmOverloads
        fun checkElementIndex(index: Int, size: Int, desc: String = "index"): Int {
            return if (index >= 0 && index < size) {
                index
            } else {
                throw IndexOutOfBoundsException(
                    badElementIndex(
                        index,
                        size,
                        desc
                    )
                )
            }
        }

        private fun badElementIndex(index: Int, size: Int, desc: String): String {
            return if (index < 0) {
                format(
                    "%s (%s) must not be negative",
                    *arrayOf<Any>(desc, Integer.valueOf(index))
                )
            } else if (size < 0) {
                throw IllegalArgumentException(StringBuilder(26).append("negative size: ").append(size).toString())
            } else {
                format(
                    "%s (%s) must be less than size (%s)",
                    *arrayOf<Any>(desc, Integer.valueOf(index), Integer.valueOf(size))
                )
            }
        }

        @JvmOverloads
        fun checkPositionIndex(index: Int, size: Int, desc: String = "index"): Int {
            return if (index >= 0 && index <= size) {
                index
            } else {
                throw IndexOutOfBoundsException(
                    badPositionIndex(
                        index,
                        size,
                        desc
                    )
                )
            }
        }

        private fun badPositionIndex(index: Int, size: Int, desc: String): String {
            return if (index < 0) {
                format(
                    "%s (%s) must not be negative",
                    *arrayOf<Any>(desc, Integer.valueOf(index))
                )
            } else if (size < 0) {
                throw IllegalArgumentException(StringBuilder(26).append("negative size: ").append(size).toString())
            } else {
                format(
                    "%s (%s) must not be greater than size (%s)",
                    *arrayOf<Any>(desc, Integer.valueOf(index), Integer.valueOf(size))
                )
            }
        }

        fun checkPositionIndexes(start: Int, end: Int, size: Int) {
            if (start < 0 || end < start || end > size) {
                throw IndexOutOfBoundsException(
                    badPositionIndexes(
                        start,
                        end,
                        size
                    )
                )
            }
        }

        private fun badPositionIndexes(start: Int, end: Int, size: Int): String {
            return if (start >= 0 && start <= size) if (end >= 0 && end <= size) format(
                "end index (%s) must not be less than start index (%s)",
                *arrayOf<Any>(Integer.valueOf(end), Integer.valueOf(start))
            ) else badPositionIndex(
                end,
                size,
                "end index"
            ) else badPositionIndex(
                start,
                size,
                "start index"
            )
        }

        internal fun format(template: String, vararg args: Any): String {
            var template = template
            template = template.toString()
            val builder = StringBuilder(template.length + 16 * args.size)
            var templateStart = 0

            var i: Int
            var placeholderStart: Int
            i = 0
            while (i < args.size) {
                placeholderStart = template.indexOf("%s", templateStart)
                if (placeholderStart == -1) {
                    break
                }

                builder.append(template.substring(templateStart, placeholderStart))
                builder.append(args[i++])
                templateStart = placeholderStart + 2
            }

            builder.append(template.substring(templateStart))
            if (i < args.size) {
                builder.append(" [")
                builder.append(args[i++])

                while (i < args.size) {
                    builder.append(", ")
                    builder.append(args[i++])
                }

                builder.append(']')
            }

            return builder.toString()
        }
    }
}