package dbft

import (
	"fmt"

	"go.uber.org/zap"
)

func (d *DBFT[H]) broadcast(msg ConsensusPayload[H]) {
	d.Logger.Debug("broadcasting message",
		zap.Stringer("type", msg.Type()),
		zap.Uint32("height", d.BlockIndex),
		zap.Uint("view", uint(d.ViewNumber)))

	msg.SetValidatorIndex(uint16(d.MyIndex))
	d.Broadcast(msg)
}

func (c *Context[H]) makePrepareRequest(force bool) ConsensusPayload[H] {
	if !c.Fill(force) {
		return nil
	}

	req := c.Config.NewPrepareRequest(c.Timestamp, c.Nonce, c.TransactionHashes)

	return c.Config.NewConsensusPayload(c, PrepareRequestType, req)
}

func (d *DBFT[H]) sendPrepareRequest(force bool) {
	msg := d.makePrepareRequest(force)
	if msg == ConsensusPayload[H](nil) {
		d.subscribeForTransactions()

		// Try one more time since there's a tiny race between an attempt to
		// construct prepare request and transactions subscription.
		msg = d.makePrepareRequest(force)
		if msg == ConsensusPayload[H](nil) {
			delay := d.maxTimePerBlock - d.timePerBlock
			d.changeTimer(delay)
			return
		}
	}
	d.unsubscribeFromTransactions()

	d.PreparationPayloads[d.MyIndex] = msg
	d.broadcast(msg)

	d.prepareSentTime = d.Timer.Now()

	delay := d.timePerBlock << (d.ViewNumber + 1)
	if d.ViewNumber == 0 {
		delay -= d.timePerBlock
	}

	d.Logger.Info("sending PrepareRequest", zap.Uint32("height", d.BlockIndex), zap.Uint("view", uint(d.ViewNumber)))
	d.changeTimer(delay)
	d.checkPrepare()
}

func (c *Context[H]) makeChangeView(ts uint64, reason ChangeViewReason) ConsensusPayload[H] {
	cv := c.Config.NewChangeView(c.ViewNumber+1, reason, ts)

	msg := c.Config.NewConsensusPayload(c, ChangeViewType, cv)
	c.ChangeViewPayloads[c.MyIndex] = msg

	return msg
}

func (d *DBFT[H]) sendChangeView(reason ChangeViewReason) {
	if d.Context.WatchOnly() {
		return
	}

	newView := d.ViewNumber + 1
	d.changeTimer(d.timePerBlock << (newView + 1))

	nc := d.CountCommitted()
	nf := d.CountFailed()

	if reason == CVTimeout && nc+nf > d.F() {
		d.Logger.Info("skip change view", zap.Int("nc", nc), zap.Int("nf", nf))
		d.sendRecoveryRequest()

		return
	}

	// Timeout while missing transactions, set the real reason.
	if !d.hasAllTransactions() && reason == CVTimeout {
		reason = CVTxNotFound
	}

	d.Logger.Info("request change view",
		zap.Int("view", int(d.ViewNumber)),
		zap.Uint32("height", d.BlockIndex),
		zap.Stringer("reason", reason),
		zap.Int("new_view", int(newView)),
		zap.Int("nc", nc),
		zap.Int("nf", nf))

	msg := d.makeChangeView(uint64(d.Timer.Now().UnixNano()), reason)
	d.StopTxFlow()
	d.broadcast(msg)
	d.checkChangeView(newView)
}

func (c *Context[H]) makePrepareResponse() ConsensusPayload[H] {
	resp := c.Config.NewPrepareResponse(c.PreparationPayloads[c.PrimaryIndex].Hash())

	msg := c.Config.NewConsensusPayload(c, PrepareResponseType, resp)
	c.PreparationPayloads[c.MyIndex] = msg

	return msg
}

func (d *DBFT[H]) sendPrepareResponse() {
	msg := d.makePrepareResponse()
	d.Logger.Info("sending PrepareResponse", zap.Uint32("height", d.BlockIndex), zap.Uint("view", uint(d.ViewNumber)))
	d.StopTxFlow()
	d.broadcast(msg)
}

func (c *Context[H]) makePreCommit() (ConsensusPayload[H], error) {
	if msg := c.PreCommitPayloads[c.MyIndex]; msg != nil {
		return msg, nil
	}

	if preB := c.CreatePreBlock(); preB != nil {
		var preData []byte
		if err := preB.SetData(c.Priv); err == nil {
			preData = preB.Data()
		} else {
			return nil, fmt.Errorf("PreCommit data construction failed: %w", err)
		}

		preCommit := c.Config.NewPreCommit(preData)

		return c.Config.NewConsensusPayload(c, PreCommitType, preCommit), nil
	}

	return nil, fmt.Errorf("failed to construct PreBlock")
}

func (c *Context[H]) makeCommit() (ConsensusPayload[H], error) {
	if msg := c.CommitPayloads[c.MyIndex]; msg != nil {
		return msg, nil
	}

	if b := c.MakeHeader(); b != nil {
		var sign []byte
		if err := b.Sign(c.Priv); err == nil {
			sign = b.Signature()
		} else {
			return nil, fmt.Errorf("header signing failed: %w", err)
		}

		commit := c.Config.NewCommit(sign)

		return c.Config.NewConsensusPayload(c, CommitType, commit), nil
	}

	return nil, fmt.Errorf("failed to construct Header")
}

func (d *DBFT[H]) sendPreCommit() {
	msg, err := d.makePreCommit()
	if err != nil {
		d.Logger.Error("failed to construct PreCommit", zap.Error(err))
		return
	}
	d.PreCommitPayloads[d.MyIndex] = msg
	d.Logger.Info("sending PreCommit", zap.Uint32("height", d.BlockIndex), zap.Uint("view", uint(d.ViewNumber)))
	d.broadcast(msg)
}

func (d *DBFT[H]) sendCommit() {
	msg, err := d.makeCommit()
	if err != nil {
		d.Logger.Error("failed to construct Commit", zap.Error(err))
		return
	}
	d.CommitPayloads[d.MyIndex] = msg
	d.Logger.Info("sending Commit", zap.Uint32("height", d.BlockIndex), zap.Uint("view", uint(d.ViewNumber)))
	d.broadcast(msg)
}

func (d *DBFT[H]) sendRecoveryRequest() {
	// If we're here, something is wrong, we either missing some messages or
	// transactions or both, so re-request missing transactions here too.
	if d.RequestSentOrReceived() && !d.hasAllTransactions() {
		d.processMissingTx()
	}
	req := d.NewRecoveryRequest(uint64(d.Timer.Now().UnixNano()))
	d.broadcast(d.NewConsensusPayload(&d.Context, RecoveryRequestType, req))
}

func (c *Context[H]) makeRecoveryMessage() ConsensusPayload[H] {
	recovery := c.Config.NewRecoveryMessage()

	for _, p := range c.PreparationPayloads {
		if p != nil {
			recovery.AddPayload(p)
		}
	}

	cv := c.LastChangeViewPayloads
	// if byte(msg.ViewNumber) == c.ViewNumber {
	// 	cv = c.changeViewPayloads
	// }
	for _, p := range cv {
		if p != nil {
			recovery.AddPayload(p)
		}
	}

	if c.PreCommitSent() {
		for _, p := range c.PreCommitPayloads {
			if p != nil {
				recovery.AddPayload(p)
			}
		}
	}

	if c.CommitSent() {
		for _, p := range c.CommitPayloads {
			if p != nil {
				recovery.AddPayload(p)
			}
		}
	}

	return c.Config.NewConsensusPayload(c, RecoveryMessageType, recovery)
}

func (d *DBFT[H]) sendRecoveryMessage() {
	d.broadcast(d.makeRecoveryMessage())
}