package lsp

import (
	"encoding/json"
	"testing"
)

func TestResolveRewrite_MultiLine_PreservesRange(t *testing.T) {
	s := newTestServer()
	s.llmClient = fakeLLM{resp: "line1\nline2"}
	uri := "file:///x.go"
	s.setDocument(uri, "package p\nvar a=1\n")
	r := Range{Start: Position{Line: 1, Character: 0}, End: Position{Line: 1, Character: 5}}
	payload := struct {
		Type        string `json:"type"`
		URI         string `json:"uri"`
		Range       Range  `json:"range"`
		Instruction string `json:"instruction"`
		Selection   string `json:"selection"`
	}{Type: "rewrite", URI: uri, Range: r, Instruction: "expand", Selection: "var a"}
	raw, _ := json.Marshal(payload)
	ca := CodeAction{Title: "Hexai: rewrite selection", Data: raw}
	resolved, ok := s.resolveCodeAction(ca)
	if !ok || resolved.Edit == nil {
		t.Fatalf("expected resolved rewrite edit")
	}
	edits := resolved.Edit.Changes[uri]
	if len(edits) != 1 {
		t.Fatalf("expected 1 edit")
	}
	if edits[0].Range != r {
		t.Fatalf("range mismatch: got %+v want %+v", edits[0].Range, r)
	}
	if edits[0].NewText == "" || !containsNewline(edits[0].NewText) {
		t.Fatalf("expected multi-line replacement text, got %q", edits[0].NewText)
	}
}

func TestResolveDiagnostics_MultiLine_PreservesRange(t *testing.T) {
	s := newTestServer()
	s.llmClient = fakeLLM{resp: "fixed\nvalue"}
	uri := "file:///x.go"
	s.setDocument(uri, "package p\nvar x = 1\n")
	r := Range{Start: Position{Line: 1, Character: 0}, End: Position{Line: 1, Character: 10}}
	payload := struct {
		Type        string       `json:"type"`
		URI         string       `json:"uri"`
		Range       Range        `json:"range"`
		Selection   string       `json:"selection"`
		Diagnostics []Diagnostic `json:"diagnostics"`
	}{Type: "diagnostics", URI: uri, Range: r, Selection: "var x = 1", Diagnostics: []Diagnostic{{Range: Range{Start: Position{Line: 1}, End: Position{Line: 1, Character: 5}}, Message: "msg"}}}
	raw, _ := json.Marshal(payload)
	ca := CodeAction{Title: "Hexai: resolve diagnostics", Data: raw}
	resolved, ok := s.resolveCodeAction(ca)
	if !ok || resolved.Edit == nil {
		t.Fatalf("expected resolved diagnostics edit")
	}
	edits := resolved.Edit.Changes[uri]
	if len(edits) != 1 {
		t.Fatalf("expected 1 edit")
	}
	if edits[0].Range != r {
		t.Fatalf("range mismatch: got %+v want %+v", edits[0].Range, r)
	}
	if edits[0].NewText == "" || !containsNewline(edits[0].NewText) {
		t.Fatalf("expected multi-line replacement text, got %q", edits[0].NewText)
	}
}

func containsNewline(s string) bool {
	for i := 0; i < len(s); i++ {
		if s[i] == '\n' {
			return true
		}
	}
	return false
}