package resolver

import (
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"

	"github.com/zzet/gortex/internal/graph"
)

func TestAttributeGoExternalCalls_StdlibFunctionMaterialised(t *testing.T) {
	g := graph.New()
	owner := "pkg/foo.go::F"
	g.AddNode(&graph.Node{ID: owner, Kind: graph.KindFunction, Name: "F", FilePath: "pkg/foo.go", Language: "go"})
	// Post-resolveExtern shape: an edge directly to stdlib::fmt::Sprintf.
	edge := &graph.Edge{From: owner, To: "stdlib::fmt::Sprintf", Kind: graph.EdgeCalls, FilePath: "pkg/foo.go", Line: 5}
	g.AddEdge(edge)

	New(g).attributeGoExternalCalls()

	// The symbol becomes a KindFunction with the right metadata.
	sym := g.GetNode("stdlib::fmt::Sprintf")
	require.NotNil(t, sym, "stdlib symbol must be materialised as a node")
	assert.Equal(t, graph.KindFunction, sym.Kind)
	assert.Equal(t, "Sprintf", sym.Name)
	assert.Equal(t, "go", sym.Language)
	assert.Equal(t, true, sym.Meta["external"])
	assert.Equal(t, "fmt", sym.Meta["module_path"])
	assert.Equal(t, "stdlib", sym.Meta["module_role"])

	// And a KindModule parent under module::go:fmt with role=stdlib.
	mod := g.GetNode("module::go:fmt")
	require.NotNil(t, mod, "module parent must be materialised")
	assert.Equal(t, graph.KindModule, mod.Kind)
	assert.Equal(t, "fmt", mod.Name)
	assert.Equal(t, "stdlib", mod.Meta["role"])
	assert.Equal(t, "go", mod.Meta["ecosystem"])

	// EdgeMemberOf: symbol -> module.
	var foundLink bool
	for e := range g.EdgesByKind(graph.EdgeMemberOf) {
		if e.From == "stdlib::fmt::Sprintf" && e.To == "module::go:fmt" {
			foundLink = true
		}
	}
	assert.True(t, foundLink, "symbol must be linked to its module via EdgeMemberOf")
}

func TestAttributeGoExternalCalls_DepUsesFullImportPath(t *testing.T) {
	g := graph.New()
	owner := "pkg/foo.go::F"
	g.AddNode(&graph.Node{ID: owner, Kind: graph.KindFunction, Name: "F", FilePath: "pkg/foo.go", Language: "go"})
	g.AddEdge(&graph.Edge{From: owner, To: "dep::github.com/stretchr/testify/assert::True", Kind: graph.EdgeCalls, FilePath: "pkg/foo.go", Line: 7})

	New(g).attributeGoExternalCalls()

	sym := g.GetNode("dep::github.com/stretchr/testify/assert::True")
	require.NotNil(t, sym)
	assert.Equal(t, "True", sym.Name)
	assert.Equal(t, "github.com/stretchr/testify/assert", sym.Meta["module_path"])
	assert.Equal(t, "dep", sym.Meta["module_role"])

	mod := g.GetNode("module::go:github.com/stretchr/testify/assert")
	require.NotNil(t, mod)
	assert.Equal(t, "assert", mod.Name, "module name must be the last path segment, not the full import path")
	assert.Equal(t, "dep", mod.Meta["role"])
}

func TestAttributeGoExternalCalls_ModuleNodeSharedAcrossSymbols(t *testing.T) {
	g := graph.New()
	owner := "pkg/foo.go::F"
	g.AddNode(&graph.Node{ID: owner, Kind: graph.KindFunction, Name: "F", FilePath: "pkg/foo.go", Language: "go"})
	// Three different functions from the same stdlib package — all
	// should attach to ONE module node, not three.
	for _, sym := range []string{"Marshal", "Unmarshal", "RawMessage"} {
		g.AddEdge(&graph.Edge{
			From: owner, To: "stdlib::encoding/json::" + sym,
			Kind: graph.EdgeCalls, FilePath: "pkg/foo.go", Line: 1,
		})
	}

	New(g).attributeGoExternalCalls()

	count := 0
	for n := range g.NodesByKind(graph.KindModule) {
		if n.ID == "module::go:encoding/json" {
			count++
		}
	}
	assert.Equal(t, 1, count, "exactly one KindModule per import path")
}

func TestAttributeGoExternalCalls_IdempotentOnRerun(t *testing.T) {
	g := graph.New()
	owner := "pkg/foo.go::F"
	g.AddNode(&graph.Node{ID: owner, Kind: graph.KindFunction, Name: "F", FilePath: "pkg/foo.go", Language: "go"})
	g.AddEdge(&graph.Edge{From: owner, To: "stdlib::os::Open", Kind: graph.EdgeCalls, FilePath: "pkg/foo.go", Line: 1})

	r := New(g)
	r.attributeGoExternalCalls()
	r.attributeGoExternalCalls() // second run must not duplicate

	syms := 0
	for n := range g.NodesByKind(graph.KindFunction) {
		if n.ID == "stdlib::os::Open" {
			syms++
		}
	}
	assert.Equal(t, 1, syms, "second pass must not duplicate the symbol node")

	memberEdges := 0
	for e := range g.EdgesByKind(graph.EdgeMemberOf) {
		if e.From == "stdlib::os::Open" && e.To == "module::go:os" {
			memberEdges++
		}
	}
	assert.Equal(t, 1, memberEdges, "second pass must not duplicate the membership edge")
}

func TestAttributeGoExternalCalls_NonExternEdgesIgnored(t *testing.T) {
	g := graph.New()
	owner := "pkg/foo.go::F"
	g.AddNode(&graph.Node{ID: owner, Kind: graph.KindFunction, Name: "F", FilePath: "pkg/foo.go", Language: "go"})
	// Real intra-repo call — must not be touched.
	g.AddNode(&graph.Node{ID: "pkg/bar.go::Helper", Kind: graph.KindFunction, Name: "Helper", FilePath: "pkg/bar.go", Language: "go"})
	g.AddEdge(&graph.Edge{From: owner, To: "pkg/bar.go::Helper", Kind: graph.EdgeCalls, FilePath: "pkg/foo.go", Line: 1})
	// And an unresolved bare name — also not in scope for this pass.
	g.AddEdge(&graph.Edge{From: owner, To: "unresolved::doSomething", Kind: graph.EdgeCalls, FilePath: "pkg/foo.go", Line: 2})

	before := []string{}
	for n := range g.NodesByKind(graph.KindModule) {
		before = append(before, n.ID)
	}
	New(g).attributeGoExternalCalls()
	after := []string{}
	for n := range g.NodesByKind(graph.KindModule) {
		after = append(after, n.ID)
	}
	assert.Equal(t, before, after, "no module nodes should be created when there are no extern-prefixed targets")
}