package calc

import (
	"gitea.zaclys.com/bvaudour/gob/number"
	"gitea.zaclys.com/bvaudour/gob/option"
)

type Calc struct {
	stack    Stack
	registry Registry
	macro    Macro
}

type CalcFunc func(*Calc) option.Option[error]
type IntCalcFunc[N integer] func(...N) CalcFunc
type WordCalcFunc func(string) CalcFunc
type CalcErrFunc func(*Calc) []error

func New() *Calc {
	return &Calc{
		registry: make(Registry),
		macro:    make(Macro),
	}
}

func (c *Calc) SetPrecision(precision option.Option[uint64], fix option.Option[bool]) {
	if p, ok := precision.Get(); ok {
		number.FloatingPrecision = p
	}

	if f, ok := fix.Get(); ok {
		number.FixedPrecision = f
	}
}

func (c *Calc) Precision() (precision uint64, fix bool) {
	return number.FloatingPrecision, number.FixedPrecision
}

func (c *Calc) Push(numbers ...number.Number) { c.stack.Push(numbers...) }
func (c *Calc) Stack() Stack                  { return c.stack.Clone() }
func (c *Calc) GetStack() (result option.Result[Stack]) {
	if c.stack.IsEmpty() {
		result = option.Err[Stack](ErrIsEmpty(errStack))
	} else {
		result = option.Ok(c.Stack())
	}

	return
}
func (c *Calc) Len() { c.Push(number.IntOf(c.stack.Len())) }

func (c *Calc) Last() option.Result[number.Number] { return c.stack.Last() }

func (c *Calc) Pop() (err option.Option[error]) {
	if e, ok := c.stack.Pop().Err(); ok {
		err = option.Some(e)
	}

	return
}

func (c *Calc) Reset() option.Option[error]          { return c.stack.Reset() }
func (c *Calc) Duplicate() option.Option[error]      { return c.stack.Duplicate() }
func (c *Calc) DuplicateStack() option.Option[error] { return c.stack.DuplicateAll() }
func (c *Calc) Reverse() option.Option[error]        { return c.stack.Reverse() }
func (c *Calc) ReverseStack() option.Option[error]   { return c.stack.ReverseAll() }
func (c *Calc) Sort() option.Option[error]           { return c.stack.Sort() }
func (c *Calc) SortDesc() option.Option[error]       { return c.stack.SortDesc() }

func (c *Calc) Registries() Registry { return c.registry.Clone() }
func (c *Calc) GetRegistries() (result option.Result[Registry]) {
	if len(c.registry) == 0 {
		result = option.Err[Registry](ErrIsEmpty(errMemory))
	} else {
		result = option.Ok(c.Registries())
	}

	return
}

func (c *Calc) Registry(k string) option.Result[Stack]      { return c.registry.Get(k) }
func (c *Calc) ResetRegistry(k string) option.Option[error] { return c.registry.Reset(k) }
func (c *Calc) ResetRegistries() option.Option[error]       { return c.registry.ResetAll() }

func (c *Calc) Store(k string) (err option.Option[error]) {
	pop := c.stack.Pop()
	if n, ok := pop.Ok(); ok {
		c.registry.Set(k, n)
	} else if e, ok := pop.Err(); ok {
		err = option.Some(e)
	}

	return
}

func (c *Calc) StoreStack(k string) (err option.Option[error]) {
	if c.stack.IsEmpty() {
		err = option.Some(ErrIsEmpty(errStack))
	} else {
		c.registry.Set(k, c.Stack()...)
		c.Reset()
	}

	return
}

func (c *Calc) Load(k string) (err option.Option[error]) {
	result := c.registry.Get(k)
	if s, ok := result.Ok(); ok {
		c.Push(s...)
	} else if e, ok := result.Err(); ok {
		err = option.Some(e)
	}

	return
}

func (c *Calc) Macros() Macro { return c.macro.Clone() }
func (c *Calc) GetMacros() (result option.Result[Macro]) {
	if len(c.macro) == 0 {
		result = option.Err[Macro](ErrIsEmpty(errMemory))
	} else {
		result = option.Ok(c.Macros())
	}

	return
}

func (c *Calc) Macro(k string) (result option.Result[MacroStack]) { return c.macro.Get(k) }
func (c *Calc) StoreMacro(k string, args ...MacroElement) {
	c.macro.Set(k, args)
}

func (c *Calc) Exec(s MacroStack) (errors []error) {
	for _, e := range s {
		if n, ok := e.Left(); ok {
			c.Push(n)
		} else if f, ok := e.Right(); ok {
			if err, ok := f(c).Get(); ok {
				errors = append(errors, err)
			}
		}
	}

	return
}

func (c *Calc) ExecMacro(k string) (errors []error) {
	result := c.macro.Get(k)
	if s, ok := result.Ok(); ok {
		errors = c.Exec(s)
	} else if err, ok := result.Err(); ok {
		errors = append(errors, err)
	}

	return
}

func (c *Calc) ResetMacro(k string) option.Option[error] { return c.macro.Reset(k) }
func (c *Calc) ResetMacros() option.Option[error]        { return c.macro.ResetAll() }
func (c *Calc) NoAction() (error option.Option[error])   { return }

func (c *Calc) If(e1, e2 MacroElement) (err option.Option[error]) {
	result := c.stack.Pop()
	if n, ok := result.Ok(); ok {
		if n.IsZero() || n.IsNan() {
			if n2, ok := e2.Left(); ok {
				c.Push(n2)
			} else if c2, ok := e2.Right(); ok {
				c2(c)
			}
		} else if n1, ok := e1.Left(); ok {
			c.Push(n1)
		} else if c1, ok := e1.Right(); ok {
			c1(c)
		}
	} else if e, ok := result.Err(); ok {
		err = option.Some(e)
	}

	return
}