package skills

import (
	"os"
	"path/filepath"
	"strings"
	"testing"
)

func writeSkill(t *testing.T, root, name, content string) {
	t.Helper()
	dir := filepath.Join(root, name)
	if err := os.MkdirAll(dir, 0o755); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(filepath.Join(dir, "SKILL.md"), []byte(content), 0o644); err != nil {
		t.Fatal(err)
	}
}

// TestLoad 验证 frontmatter 解析、优先级覆盖与缺省名。
func TestLoad(t *testing.T) {
	user := t.TempDir()
	proj := t.TempDir()

	writeSkill(t, user, "deploy", "---\nname: deploy\ndescription: \"How to deploy\"\nallowed-tools: read, grep\n---\n\nStep 1: run make deploy\n")
	writeSkill(t, user, "notes", "No frontmatter here, just body.\n")
	writeSkill(t, proj, "deploy", "---\ndescription: Project override\n---\nProject deploy steps.\n")

	got := Load(proj, user) // 项目级优先
	if len(got) != 2 {
		t.Fatalf("want 2 skills, got %d: %+v", len(got), got)
	}
	byName := map[string]Skill{}
	for _, s := range got {
		byName[s.Name] = s
	}
	dep := byName["deploy"]
	if dep.Description != "Project override" || !strings.Contains(dep.Body, "Project deploy steps") {
		t.Fatalf("project skill should win: %+v", dep)
	}
	notes := byName["notes"]
	if notes.Name != "notes" || !strings.Contains(notes.Body, "just body") {
		t.Fatalf("missing frontmatter should fall back to dir name: %+v", notes)
	}
	if len(dep.AllowedTools) != 0 {
		t.Fatalf("override should not inherit allowed-tools from user version")
	}

	// 用户级版本的字段
	gotUser := Load(user)
	var found bool
	for _, s := range gotUser {
		if s.Name == "deploy" {
			found = true
			if len(s.AllowedTools) != 2 || s.AllowedTools[0] != "read" || s.AllowedTools[1] != "grep" {
				t.Fatalf("allowed-tools parse: %+v", s.AllowedTools)
			}
			if !strings.Contains(s.Body, "make deploy") {
				t.Fatalf("body: %q", s.Body)
			}
		}
	}
	if !found {
		t.Fatal("user deploy skill missing")
	}
}

// TestPromptSection：列表注入、预算截断、空列表为空。
func TestPromptSection(t *testing.T) {
	if PromptSection(nil) != "" {
		t.Fatal("empty skills should produce empty section")
	}
	sk := []Skill{{Name: "deploy", Description: "How to deploy", AllowedTools: []string{"read"}}}
	sec := PromptSection(sk)
	if !strings.Contains(sec, "- deploy: How to deploy") || !strings.Contains(sec, "allowed-tools: read") {
		t.Fatalf("section: %q", sec)
	}
	many := make([]Skill, 200)
	for i := range many {
		many[i] = Skill{Name: strings.Repeat("s", 40) + string(rune('a'+i%26)) + string(rune(i))}
	}
	if got := PromptSection(many); len(got) > maxPromptChars+100 {
		t.Fatalf("budget exceeded: %d", len(got))
	}
}