package lockstep

import (
    "bytes"
    "ripple/bug"
	"ripple/config"
	"ripple/types"
)

func (l *Lockstep) Enqueue(id types.UserIdentifier, instr types.Instruction) bool {
    queue := l.mustGetAccount(id)
    if len(queue) >= config.BufferSize {
        return false
    }
    queue = append(queue, instr)
    l.queues[id] = queue
    if len(queue) == 1 {
        l.doTurn(id)
    }
    return true
}

func (l *Lockstep) isValidTransaction(id types.UserIdentifier, instr types.Instruction) bool {
	stateCopy := l.st.Clone()
    if _, err := l.dispatch(&stateCopy, id, instr); err != nil {
        return false
    }
    return true
}

func (l *Lockstep) dequeue(id types.UserIdentifier) (types.Instruction, bool) {
    queue := l.mustGetAccount(id)
    for len(queue) > 0 {
        instr := queue[0]
        queue = queue[1:]
        if l.isValidTransaction(id, instr) {
            l.queues[id] = queue
            return instr, true
        }
    }
    l.queues[id] = queue
    return types.Instruction{}, false
}

func (l *Lockstep) peek(id types.UserIdentifier) (types.Instruction, bool) {
    queue := l.mustGetAccount(id)
    for len(queue) > 0 {
        instr := queue[0]
        if l.isValidTransaction(id, instr) {
            l.queues[id] = queue
            instr.Command = cmdToExternalCmd(instr.Command)
            return instr, true
        }
        queue = queue[1:]
    }
    l.queues[id] = queue
    return types.Instruction{}, false
}

func (l *Lockstep) RemoveAccount(id types.UserIdentifier) {
    if !l.accountExists(id) {
        panic(bug.BugStateViolated)
    }
    delete(l.queues, id)
}

func (l *Lockstep) AddAccount(id types.UserIdentifier) {
    if l.accountExists(id) {
        panic(bug.BugStateViolated)
    }
    l.queues[id] = make([]types.Instruction, 0)
}

func (l *Lockstep) InQueue(id types.UserIdentifier, cmpInstr types.Instruction) bool {
    queue := l.mustGetAccount(id)
    for _, instr := range queue {
        if instr.Command == cmpInstr.Command && bytes.Equal(instr.Arguments, cmpInstr.Arguments) {
            return true
        }
    }
    return false
}