package coll

import "fmt"

const (
	DefaultSize = 4
)

type Vector[T any] []T

func New[T any]() Vector[T] {
	return WithCap[T](DefaultSize)
}

func WithCap[T any](capacity int) Vector[T] {
	return make(Vector[T], 0, capacity)
}

func From[T any](v []T) Vector[T] {
	return Vector[T](v)
}

func (v Vector[T]) Push(t T) Vector[T] {
	if len(v) == cap(v) {
		v = v.upsize()
	}

	v = v[:len(v)+1]
	v[len(v)-1] = t
	return v
}

func (v Vector[T]) Append(t ...T) Vector[T] {
	if cap(v)-len(v) < len(t) {
		v = v.upsizeSpecific(len(t))
	}
	startLen := len(v)
	v = v[:len(v)+len(t)]
	var tIndex int
	for index := startLen; index < cap(v); index++ {
		v[index] = t[tIndex]
		tIndex++
	}
	return v
}

func (v Vector[T]) Remove(index int) Vector[T] {
	return From(append(v[:index], v[index+1:]...))
}

// Faster remove function that can be used on vectors where ordering doesn't matter
func (v Vector[T]) RemoveUnordered(index int) Vector[T] {
	v[index] = v[len(v)-1]
	return v[:len(v)-1]
}

func (v Vector[T]) upsize() Vector[T] {
	return v.upsizeSpecific(cap(v))
}

func (v Vector[T]) upsizeSpecific(extraSize int) Vector[T] {
	resized := make([]T, len(v), cap(v)+extraSize)
	copy(resized, v)
	return resized
}

func (v Vector[T]) panicIndex(index int) {
	min := -1
	if len(v) != 0 {
		min = 0
	}
	panic(fmt.Sprintf("index %d out of range [%d;%d)", index, min, len(v)))
}

// GetSoft tries to get the requested index, or returns a default value if
// it's out of range
func (v Vector[T]) GetSoft(index int) T {
	var result T
	if index < 0 || index >= len(v) {
		return result
	}
	return v[index]
}

func (v Vector[T]) Get(index int) T {
	if index < 0 || index >= len(v) {
		v.panicIndex(index)
	}
	return v[index]
}

func (v Vector[T]) Set(index int, value T) Vector[T] {
	if index < 0 || index >= len(v) {
		v.panicIndex(index)
	}
	v[index] = value
	return v
}

func (v Vector[T]) Pop() (T, Vector[T]) {
	t := v[len(v)-1]
	return t, v[:len(v)-1]
}

func (v Vector[T]) Sub(start, end int) Vector[T] {
	if start >= len(v) {
		v.panicIndex(start)
	}
	if end >= len(v) {
		v.panicIndex(end)
	}
	if start < 0 {
		return From(v[:end])
	}
	if end < 0 {
		return From(v[start:])
	}
	return From(v[start:end])
}

func (v Vector[T]) Filter(f func(T) bool) Vector[T] {
	return Filter(v, f)
}

func (v Vector[T]) Any(f func(T) bool) bool {
	return Any(v, f)
}

func (v Vector[T]) Take(howMany int) Vector[T] {
	return Take(v, howMany)
}

func (v Vector[T]) Clone() Vector[T] {
	clone := make([]T, len(v))
	copy(clone, v)
	v = clone
	return v
}