clerk @ b082668

package lsp

import (

	"context"

	"slices"

	"go.lsp.dev/protocol"

	"go.lsp.dev/uri"

	"olexsmir.xyz/clerk/internal/lsp/lsputil"

	"olexsmir.xyz/clerk/journal/ast"

	"olexsmir.xyz/clerk/journal/lexer"

	"olexsmir.xyz/clerk/journal/token"

)

func (s *server) SemanticTokensFull(ctx context.Context, params *protocol.SemanticTokensParams) (*protocol.SemanticTokens, error) {

	tokens, ok := s.tokensForDoc(params.TextDocument.URI)

	if !ok {

		return &protocol.SemanticTokens{}, nil

	}

	return &protocol.SemanticTokens{Data: encodeSemTokens(tokens)}, nil

}

func (s *server) SemanticTokensRange(ctx context.Context, params *protocol.SemanticTokensRangeParams) (*protocol.SemanticTokens, error) {

	tokens, ok := s.tokensForDoc(params.TextDocument.URI)

	if !ok {

		return &protocol.SemanticTokens{}, nil

	}

	start := int(params.Range.Start.Line)

	end := int(params.Range.End.Line)

	var filtered []semanticToken

	for _, t := range tokens {

		if t.line >= uint32(start) && t.line <= uint32(end) {

			filtered = append(filtered, t)

		}

	}

	return &protocol.SemanticTokens{Data: encodeSemTokens(filtered)}, nil

}

func (s *server) tokensForDoc(doc uri.URI) ([]semanticToken, bool) {

	state, ok := s.getDocState(doc)

	if !ok {

		return nil, false

	}

	return tokenizeForSemantics(state.text, state.journal), true

}

// Implementation

const (

	SemanticDirective = iota

	SemanticDate

	SemanticAccount

	SemanticCommodity

	SemanticAmount

	SemanticStatus

	SemanticComment

	SemString

	SemOperator

	SemProperty

	semTypeCount // used to ensure we dont go out of bound

)

var tokenTypeStrings = []string{

	string(protocol.SemanticTokenTypesKeyword),   // directive

	string(protocol.SemanticTokenTypesClass),     // date

	string(protocol.SemanticTokenTypesNamespace), // account

	string(protocol.SemanticTokenTypesType),      // commodity

	string(protocol.SemanticTokenTypesNumber),    // amount

	string(protocol.SemanticTokenTypesOperator),  // status

	string(protocol.SemanticTokenTypesComment),   // comment

	string(protocol.SemanticTokenTypesString),    // string

	string(protocol.SemanticTokenTypesOperator),  // operator

	string(protocol.SemanticTokenTypesProperty),  // property

}

const (

	modifierAbstract = 1 << 0 // virtual account

	modifierNegative = 1 << 1 // negative amount

)

var modifierStrings = []string{

	"abstract", // bit 0

	"negative", // bit 1

}

func getSemanticTokensLegend() protocol.SemanticTokensLegend {

	return protocol.SemanticTokensLegend{

		TokenTypes:     tokenTypeStrings,

		TokenModifiers: modifierStrings,

	}

}

type semanticToken struct {

	line      uint32 // 0-based

	col       uint32 // 0-based UTF-16

	length    uint32 // UTF-16 code units

	tokenType uint32

	modifiers uint32

}

func tokenizeForSemantics(content string, j *ast.Journal) []semanticToken {

	if j == nil || len(j.Errors) > 0 {

		return semLexerFallback(content)

	}

	return visitEntries(content, j)

}

// visitEntries walks the AST and emits semantic tokens.

func visitEntries(content string, j *ast.Journal) []semanticToken {

	var out []semanticToken

	emit := func(s token.Span, tokType uint32, mods uint32) {

		if s.Start.Offset >= s.End.Offset {

			return

		}

		out = append(out, semanticTokenAt(content, s, tokType, mods))

	}

	for _, e := range j.Entries {

		visitEntry(content, e, emit)

	}

	return out

}

// semanticTokenAt converts a source span into a semantic token.

func semanticTokenAt(content string, s token.Span, tokType, mods uint32) semanticToken {

	line, col := lsputil.LineCol(content, s.Start.Offset)

	length := lsputil.Utf16Len(content, s.Start.Offset, s.End.Offset)

	return semanticToken{

		line:      uint32(line),

		col:       uint32(col),

		length:    uint32(length),

		tokenType: tokType,

		modifiers: mods,

	}

}

func visitEntry(content string, e ast.Entry, emit semEmitFn) {

	switch e := e.(type) {

	case *ast.Transaction:

		visitTransaction(content, e, emit)

	case *ast.PeriodicTransaction:

		visitPeriodicTransaction(content, e, emit)

	case *ast.AutomatedTransaction:

		visitAutomatedTransaction(content, e, emit)

	case *ast.AccountDirective:

		emit(directiveKeyword(e.Span, "account"), SemanticDirective, 0)

		emit(e.Account.Span, SemanticAccount, 0)

		if e.Comment != nil {

			emit(e.Comment.Span, SemanticComment, 0)

		}

	case *ast.CommodityDirective:

		emit(directiveKeyword(e.Span, "commodity"), SemanticDirective, 0)

		if e.Format.Span.End.Offset > 0 {

			semEmitAmount(content, &e.Format, emit)

		} else if e.CommoditySpan.Start.Offset > 0 && e.CommoditySpan.End.Offset > 0 {

			emit(e.CommoditySpan, SemanticCommodity, 0)

		}

		if e.Comment != nil {

			emit(e.Comment.Span, SemanticComment, 0)

		}

	case *ast.IncludeDirective:

		emitDirective(content, e.Span, len("include"), SemString, e.Comment, emit)

	case *ast.PayeeDirective:

		emitDirective(content, e.Span, len("payee"), SemProperty, e.Comment, emit)

	case *ast.TagDirective:

		emitDirective(content, e.Span, len("tag"), SemProperty, e.Comment, emit)

	case *ast.AliasDirective:

		emit(directiveKeyword(e.Span, "alias"), SemanticDirective, 0)

		emit(e.From.Span, SemanticAccount, 0)

		if op, ok := betweenSpan(content, e.Span.Start.File, e.From.Span.End.Offset, e.To.Span.Start.Offset); ok {

			emit(op, SemOperator, 0)

		}

		emit(e.To.Span, SemanticAccount, 0)

		if e.Comment != nil {

			emit(e.Comment.Span, SemanticComment, 0)

		}

	case *ast.YearDirective:

		kwLen := len("year")

		if content[e.Span.Start.Offset] == 'Y' {

			kwLen = 1

		}

		emitDirective(content, e.Span, kwLen, SemProperty, e.Comment, emit)

	case *ast.DecimalMarkDirective:

		emitDirective(content, e.Span, len("decimal-mark"), SemProperty, e.Comment, emit)

	case *ast.DefaultCommodityDirective:

		emit(directiveKeyword(e.Span, "D"), SemanticDirective, 0)

		semEmitAmount(content, &e.Amount, emit)

		if e.Comment != nil {

			emit(e.Comment.Span, SemanticComment, 0)

		}

	case *ast.MarketPriceDirective:

		emit(directiveKeyword(e.Span, "P"), SemanticDirective, 0)

		emit(e.DateTime.Date.Span, SemanticDate, 0)

		if e.DateTime.Time != nil {

			emit(e.DateTime.Time.Span, SemanticDate, 0)

		}

		// commodity: text between the date (or time) and the amount

		commStart := e.DateTime.Date.Span.End.Offset

		if e.DateTime.Time != nil {

			commStart = e.DateTime.Time.Span.End.Offset

		}

		if comm, ok := betweenSpan(content, e.Span.Start.File, commStart, e.Amount.Span.Start.Offset); ok {

			emit(comm, SemanticCommodity, 0)

		}

		semEmitAmount(content, &e.Amount, emit)

		if e.Comment != nil {

			emit(e.Comment.Span, SemanticComment, 0)

		}

	case *ast.ConversionDirective:

		emit(directiveKeyword(e.Span, "C"), SemanticDirective, 0)

		semEmitAmount(content, &e.From, emit)

		// = operator: text between the two amounts

		if op, ok := betweenSpan(content, e.Span.Start.File, e.From.Span.End.Offset, e.To.Span.Start.Offset); ok {

			emit(op, SemOperator, 0)

		}

		semEmitAmount(content, &e.To, emit)

		if e.Comment != nil {

			emit(e.Comment.Span, SemanticComment, 0)

		}

	case *ast.Comment:

		emit(e.Span, SemanticComment, 0)

	case *ast.CommentBlockDirective:

		emit(e.Span, SemanticComment, 0)

	case *ast.IgnoredDirective:

		emitDirective(content, e.Span, len("N"), SemProperty, e.Comment, emit)

	case *ast.ApplyDirective:

		emitDirective(content, e.Span, len("apply"), SemProperty, e.Comment, emit)

	case *ast.EndDirective:

		emitDirective(content, e.Span, len("end"), SemProperty, e.Comment, emit)

	case *ast.BlankLine:

	}

}

func visitTransaction(content string, t *ast.Transaction, emit semEmitFn) {

	emit(t.Date.Span, SemanticDate, 0)

	if t.SecondDate != nil {

		emit(t.SecondDate.Span, SemanticDate, 0)

	}

	if t.Status.Value != ast.StatusNone {

		emit(t.Status.Span, SemanticStatus, 0)

	}

	if t.Code != nil {

		emit(t.Code.Span, SemString, 0)

	}

	if t.Payee != nil {

		emit(t.Payee.Span, SemProperty, 0)

	}

	if t.Note != nil {

		emit(t.Note.Span, SemProperty, 0)

	}

	if t.Comment != nil {

		emit(t.Comment.Span, SemanticComment, 0)

	}

	for i := range t.HeaderComments {

		emit(t.HeaderComments[i].Span, SemanticComment, 0)

	}

	for _, p := range t.Postings {

		visitPosting(content, p, emit)

	}

}

func visitPeriodicTransaction(content string, pt *ast.PeriodicTransaction, emit semEmitFn) {

	// ~ operator is at the start of the period span

	emit(offsetSpan(pt.Span.Start.File, pt.Span.Start.Offset, pt.Span.Start.Offset+1), SemOperator, 0)

	// The period span covers the whole expr, including any "from ... to ..." dates

	if pt.Period.Span.End.Offset > pt.Period.Span.Start.Offset {

		var dates []*ast.Date

		if pt.Period.From != nil {

			dates = append(dates, pt.Period.From)

		}

		if pt.Period.To != nil {

			dates = append(dates, pt.Period.To)

		}

		pos := pt.Period.Span.Start.Offset

		for _, d := range dates {

			if d.Span.Start.Offset > pos {

				emit(offsetSpan(pt.Period.Span.Start.File, pos, d.Span.Start.Offset), SemProperty, 0)

			}

			emit(d.Span, SemanticDate, 0)

			pos = d.Span.End.Offset

		}

		if pos < pt.Period.Span.End.Offset {

			emit(offsetSpan(pt.Period.Span.Start.File, pos, pt.Period.Span.End.Offset), SemProperty, 0)

		}

	}

	if pt.Description != nil {

		emit(pt.Description.Span, SemProperty, 0)

	}

	if pt.Comment != nil {

		emit(pt.Comment.Span, SemanticComment, 0)

	}

	for i := range pt.HeaderComments {

		emit(pt.HeaderComments[i].Span, SemanticComment, 0)

	}

	for _, p := range pt.Postings {

		visitPosting(content, p, emit)

	}

}

func visitAutomatedTransaction(content string, at *ast.AutomatedTransaction, emit semEmitFn) {

	// = operator is at the start of the expression span

	emit(offsetSpan(at.Span.Start.File, at.Span.Start.Offset, at.Span.Start.Offset+1), SemOperator, 0)

	if at.Expr.Value != "" {

		emit(at.Expr.Span, SemString, 0)

	}

	if at.Comment != nil {

		emit(at.Comment.Span, SemanticComment, 0)

	}

	for i := range at.HeaderComments {

		emit(at.HeaderComments[i].Span, SemanticComment, 0)

	}

	for _, p := range at.Postings {

		visitPosting(content, p, emit)

	}

}

func visitPosting(content string, p *ast.Posting, emit semEmitFn) {

	if p.Status.Value != ast.StatusNone {

		emit(p.Status.Span, SemanticStatus, 0)

	}

	// virtual brackets

	if p.Type == ast.PostingVirtualUnbalanced || p.Type == ast.PostingVirtualBalanced {

		// opening bracket

		for off := p.Span.Start.Offset; off < p.Account.Span.Start.Offset && off < p.Span.End.Offset; off++ {

			if content[off] == '(' || content[off] == '[' {

				brSpan := token.Span{Start: offsetPos(p.Span.Start.File, off), End: offsetPos(p.Span.Start.File, off+1)}

				emit(brSpan, SemOperator, modifierAbstract)

				break

			}

		}

		// closing bracket

		for off := p.Account.Span.End.Offset; off < p.Span.End.Offset; off++ {

			if content[off] == ')' || content[off] == ']' {

				brSpan := token.Span{Start: offsetPos(p.Span.Start.File, off), End: offsetPos(p.Span.Start.File, off+1)}

				emit(brSpan, SemOperator, modifierAbstract)

				break

			}

		}

	}

	emit(p.Account.Span, SemanticAccount, 0)

	if p.Amount != nil {

		semEmitAmount(content, p.Amount, emit)

	}

	if p.Cost != nil {

		semEmitCost(content, p.Cost, emit)

	}

	if p.Balance != nil {

		semEmitBalanceAssertion(content, p.Balance, emit)

	}

	if p.Comment != nil {

		emit(p.Comment.Span, SemanticComment, 0)

	}

	for i := range p.Comments {

		emit(p.Comments[i].Span, SemanticComment, 0)

	}

}

// directiveKeyword returns the span of the leading keyword on a directive line.

func directiveKeyword(e token.Span, kw string) token.Span {

	return token.Span{Start: e.Start, End: offsetPos(e.Start.File, e.Start.Offset+len(kw))}

}

// directiveValue returns the trimmed span of the text after the keyword end

// offset, up to the inline comment or the end of the line.

func directiveValue(content string, e token.Span, comment *ast.Comment, kwEnd int) (token.Span, bool) {

	end := e.End.Offset

	if comment != nil {

		end = comment.Span.Start.Offset

	}

	return betweenSpan(content, e.Start.File, kwEnd, end)

}

func semEmitAmount(content string, a *ast.Amount, emit semEmitFn) {

	if a == nil {

		return

	}

	hasCommodity := a.CommoditySpan.Start.Offset > 0 && a.CommoditySpan.End.Offset > 0

	if hasCommodity && a.CommodityPos == ast.CommodityBefore {

		emit(a.CommoditySpan, SemanticCommodity, 0)

		semEmitQuantity(content, a, emit)

		return

	}

	semEmitQuantity(content, a, emit)

	if hasCommodity {

		emit(a.CommoditySpan, SemanticCommodity, 0)

	}

}

func semEmitQuantity(content string, a *ast.Amount, emit semEmitFn) {

	qStart, qEnd := quantitySpan(content, a)

	if qEnd <= qStart {

		return

	}

	mods := uint32(0)

	if a.IsNegative {

		mods |= modifierNegative

	}

	emit(offsetSpan(a.Span.Start.File, qStart, qEnd), SemanticAmount, mods)

}

func quantitySpan(content string, a *ast.Amount) (int, int) {

	start, end := a.Span.Start.Offset, a.Span.End.Offset

	switch {

	case a.Commodity == "":

		// bare quantity

	case a.CommodityPos == ast.CommodityBefore:

		// "$50.00" or "$   50.00": quantity follows the commodity span

		start = a.CommoditySpan.End.Offset

	default: // CommodityAfter

		// "50.00 USD" or "50.00     USD": quantity precedes the commodity

		end = a.CommoditySpan.Start.Offset

	}

	for start < end && (content[start] == ' ' || content[start] == '\t') {

		start++

	}

	for end > start && (content[end-1] == ' ' || content[end-1] == '\t') {

		end--

	}

	return start, end

}

type semEmitFn func(token.Span, uint32, uint32)

func emitDirective(content string, e token.Span, kwLen int, valType uint32, comment *ast.Comment, emit semEmitFn) {

	kwEnd := e.Start.Offset + kwLen

	emit(token.Span{Start: e.Start, End: offsetPos(e.Start.File, kwEnd)}, SemanticDirective, 0)

	if v, ok := directiveValue(content, e, comment, kwEnd); ok {

		emit(v, valType, 0)

	}

	if comment != nil {

		emit(comment.Span, SemanticComment, 0)

	}

}

func semEmitCost(content string, c *ast.Cost, emit semEmitFn) {

	if c.IsTotal {

		emit(token.Span{Start: c.Span.Start, End: offsetPos(c.Span.Start.File, c.Span.Start.Offset+2)}, SemOperator, 0)

	} else {

		emit(token.Span{Start: c.Span.Start, End: offsetPos(c.Span.Start.File, c.Span.Start.Offset+1)}, SemOperator, 0)

	}

	semEmitAmount(content, &c.Amount, emit)

}

func semEmitBalanceAssertion(content string, ba *ast.BalanceAssertion, emit semEmitFn) {

	// The operator is the run of '=', ':', '*' chars from the span start.

	// The ':' of ':=' precedes the '=' token, so back up one offset.

	opStart := ba.Span.Start.Offset

	if ba.IsAssignment && opStart > 0 {

		opStart--

	}

	opEnd := opStart

	for opEnd < ba.Span.End.Offset && (content[opEnd] == '=' || content[opEnd] == ':' || content[opEnd] == '*') {

		opEnd++

	}

	emit(token.Span{Start: offsetPos(ba.Span.Start.File, opStart), End: offsetPos(ba.Span.Start.File, opEnd)}, SemOperator, 0)

	semEmitAmount(content, &ba.Amount, emit)

	if ba.Cost != nil {

		semEmitCost(content, ba.Cost, emit)

	}

}

// semLexerFallback produces semantic tokens using only the lexer (for unparseable documents).

func semLexerFallback(content string) []semanticToken {

	l := lexer.New("", []byte(content))

	var out []semanticToken

	var commentStart, commentEnd int // 0 = not inside a comment line

	take := func(span token.Span, tokType uint32, mods uint32) {

		out = append(out, semanticTokenAt(content, span, tokType, mods))

	}

	for {

		tok := l.Next()

		if tok.Type == token.EOF {

			if commentStart > 0 {

				take(token.Span{Start: offsetPos("", commentStart), End: offsetPos("", commentEnd)}, SemanticComment, 0)

			}

			break

		}

		if tok.Type == token.NEWLINE {

			if commentStart > 0 {

				take(token.Span{Start: offsetPos("", commentStart), End: offsetPos("", commentEnd)}, SemanticComment, 0)

				commentStart, commentEnd = 0, 0

			}

			continue

		}

		if tok.Type == token.WHITESPACE || tok.Type == token.INDENT {

			continue

		}

		tokType := uint32(SemString)

		if commentStart > 0 {

			tokType = SemanticComment

			if tok.Span.End.Offset > commentEnd {

				commentEnd = tok.Span.End.Offset

			}

			continue

		}

		switch tok.Type {

		case token.SEMICOLON, token.HASH, token.PERCENT:

			tokType = SemanticComment

			commentStart = tok.Span.Start.Offset

			commentEnd = tok.Span.End.Offset

			continue

		case token.STAR:

			tokType = SemanticComment // * at col 0 is comment marker

			commentStart = tok.Span.Start.Offset

			commentEnd = tok.Span.End.Offset

			continue

		case token.ACCOUNT, token.COMMODITY, token.INCLUDE, token.ALIAS,

			token.PAYEE, token.TAG, token.APPLY, token.END, token.COMMENTKW,

			token.YEAR, token.DECIMALMARK, token.D, token.P, token.N, token.C:

			tokType = SemanticDirective

		case token.DATE:

			tokType = SemanticDate

		case token.INT, token.DECIMAL:

			tokType = SemanticAmount

		case token.COMMODITYMARK:

			tokType = SemanticCommodity

		case token.BANG:

			tokType = SemanticStatus

		case token.AT, token.ATAT, token.EQ, token.EQEQ, token.EQEQEQ, token.EQSTAR:

			tokType = SemOperator

		}

		take(tok.Span, tokType, 0)

	}

	return out

}

func encodeSemTokens(tokens []semanticToken) []uint32 {

	if len(tokens) == 0 {

		return nil

	}

	slices.SortFunc(tokens, func(a, b semanticToken) int {

		if a.line != b.line {

			return int(a.line) - int(b.line)

		}

		return int(a.col) - int(b.col)

	})

	data := make([]uint32, 0, len(tokens)*5)

	var prevLine, prevCol uint32

	for _, t := range tokens {

		var deltaLine, deltaCol uint32

		if t.line == prevLine {

			deltaLine = 0

			deltaCol = t.col - prevCol

		} else {

			deltaLine = t.line - prevLine

			deltaCol = t.col

		}

		data = append(data, deltaLine, deltaCol, t.length, t.tokenType, t.modifiers)

		prevLine = t.line

		prevCol = t.col

	}

	return data

}

// betweenSpan returns the span of the text between two offsets, trimmed of surrounding whitespace.

func betweenSpan(content, file string, start, end int) (token.Span, bool) {

	for start < end && (content[start] == ' ' || content[start] == '\t') {

		start++

	}

	for end > start && (content[end-1] == ' ' || content[end-1] == '\t' || content[end-1] == '\n' || content[end-1] == '\r') {

		end--

	}

	if end <= start {

		return token.Span{}, false

	}

	return token.Span{Start: offsetPos(file, start), End: offsetPos(file, end)}, true

}

func offsetPos(file string, offset int) token.Pos { return token.Pos{File: file, Offset: offset} }

func offsetSpan(file string, start, end int) token.Span {

	return token.Span{Start: offsetPos(file, start), End: offsetPos(file, end)}

}