package build

import (
	"fmt"

	"git.akyoto.dev/cli/q/src/build/asm"
	"git.akyoto.dev/cli/q/src/build/ast"
	"git.akyoto.dev/cli/q/src/build/cpu"
	"git.akyoto.dev/go/color/ansi"
)

// compiler is the data structure we embed in each function to preserve compilation state.
type compiler struct {
	err         error
	definitions map[string]*Definition
	variables   map[string]*Variable
	functions   map[string]*Function
	finished    chan struct{}
	assembler   asm.Assembler
	debug       []debug
	cpu         cpu.CPU
	count       counter
	sideEffects int
}

// counter stores how often a certain statement appeared so we can generate a unique label from it.
type counter struct {
	loop int
}

// debug is used to look up the source code at the given position.
type debug struct {
	source   ast.Node
	position int
}

// PrintInstructions shows the assembly instructions.
func (c *compiler) PrintInstructions() {
	ansi.Dim.Println("╭──────────────────────────────────────╮")

	for i, x := range c.assembler.Instructions {
		instruction := c.sourceAt(i)

		if instruction != nil {
			ansi.Dim.Println("├──────────────────────────────────────┤")
		}

		ansi.Dim.Print("│ ")

		if x.Mnemonic == asm.LABEL {
			ansi.Yellow.Printf("%-36s", x.Data.String()+":")
		} else {
			ansi.Green.Printf("%-8s", x.Mnemonic.String())

			if x.Data != nil {
				fmt.Printf("%-28s", x.Data.String())
			} else {
				fmt.Printf("%-28s", "")
			}
		}

		ansi.Dim.Print(" │\n")
	}

	ansi.Dim.Println("╰──────────────────────────────────────╯")
}

// sourceAt retrieves the source code at the given position or `nil`.
func (c *compiler) sourceAt(position int) ast.Node {
	for _, record := range c.debug {
		if record.position == position {
			return record.source
		}

		if record.position > position {
			return nil
		}
	}

	return nil
}