package template_test

import (
	"bytes"
	"os"
	"os/exec"
	"path/filepath"
	"runtime"
	"strings"
	"testing"
	"time"

	"chat-agent-system/internal/template"
)

func repoRoot(t *testing.T) string {
	t.Helper()
	_, file, _, ok := runtime.Caller(0)
	if !ok {
		t.Fatal("runtime.Caller")
	}
	return filepath.Clean(filepath.Join(filepath.Dir(file), "..", ".."))
}

func TestDockerfileCopiesTemplatesAndConfigsToApp(t *testing.T) {
	raw, err := os.ReadFile(filepath.Join(repoRoot(t), "deploy", "app", "Dockerfile"))
	if err != nil {
		t.Fatal(err)
	}
	text := string(raw)
	for _, line := range []string{
		"COPY templates /app/templates",
		"COPY configs /app/configs",
		"WORKDIR /app",
	} {
		if !strings.Contains(text, line) {
			t.Fatalf("deploy/app/Dockerfile must contain %q so the image runtime can read official docs", line)
		}
	}
}

func TestDockerignoreKeepsOfficialTemplateDocs(t *testing.T) {
	root := repoRoot(t)
	patterns := readDockerignore(t, filepath.Join(root, ".dockerignore"))
	docs, err := filepath.Glob(filepath.Join(root, "templates", "docs", "*.md"))
	if err != nil || len(docs) == 0 {
		t.Fatalf("templates/docs/*.md missing on disk: %v", err)
	}
	for _, abs := range docs {
		rel, err := filepath.Rel(root, abs)
		if err != nil {
			t.Fatal(err)
		}
		rel = filepath.ToSlash(rel)
		if dockerIgnored(patterns, rel) {
			t.Fatalf(".dockerignore excludes %s; COPY templates and go:embed docs/*.md cannot see it in the image", rel)
		}
	}
	if dockerIgnored(patterns, "templates/embed.go") {
		t.Fatal("templates/embed.go must stay in the go-builder context")
	}
	if dockerIgnored(patterns, "configs/agents/writer.md") {
		t.Fatal("configs/agents/*.md must stay in the image for GetAgentInstruction")
	}
}

func TestGetDocTemplate_AppRootLayout(t *testing.T) {
	root := repoRoot(t)
	app := filepath.Join(t.TempDir(), "app")
	dest := filepath.Join(app, "templates", "docs")
	if err := os.MkdirAll(dest, 0o755); err != nil {
		t.Fatal(err)
	}
	src := filepath.Join(root, "templates", "docs", "bd_prelim_design.md")
	body, err := os.ReadFile(src)
	if err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(filepath.Join(dest, "bd_prelim_design.md"), body, 0o644); err != nil {
		t.Fatal(err)
	}
	agentDir := filepath.Join(app, "configs", "agents")
	if err := os.MkdirAll(agentDir, 0o755); err != nil {
		t.Fatal(err)
	}
	writer, err := os.ReadFile(filepath.Join(root, "configs", "agents", "writer.md"))
	if err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(filepath.Join(agentDir, "writer.md"), writer, 0o644); err != nil {
		t.Fatal(err)
	}
	t.Setenv("APP_ROOT", app)
	t.Chdir(app)
	got, err := template.GetDocTemplate("prelim_design")
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(got, "系统初步设计方案") || !strings.Contains(got, "子系统划分") {
		t.Fatalf(" /app layout must yield the official template, got %d bytes", len(got))
	}
	if strings.Contains(got, "## 1. 结论") && !strings.Contains(got, "子系统划分") {
		t.Fatal("must not use the two-section stub")
	}
	inst, err := template.GetAgentInstruction("writer")
	if err != nil {
		t.Fatalf("image /app/configs/agents must be readable: %v", err)
	}
	if strings.TrimSpace(inst) == "" {
		t.Fatal("writer instruction empty")
	}
}

func TestDockerBuildContext_TemplatesDocsReadable(t *testing.T) {
	if _, err := exec.LookPath("docker"); err != nil {
		t.Skip("docker CLI not available")
	}
	root := repoRoot(t)
	df := filepath.Join(t.TempDir(), "Dockerfile")
	// Same context and COPY destinations as deploy/app/Dockerfile final stage.
	if err := os.WriteFile(df, []byte("FROM debian:bookworm-slim\nWORKDIR /app\nCOPY templates /app/templates\nCOPY configs /app/configs\n"), 0o644); err != nil {
		t.Fatal(err)
	}
	tag := "agent-system-templates-smoke:local"
	build := exec.Command("docker", "build", "-f", df, "-t", tag, ".")
	build.Dir = root
	out, err := runTimed(build, 3*time.Minute)
	if err != nil {
		t.Fatalf("docker build context failed: %v\n%s", err, out)
	}
	t.Cleanup(func() {
		_ = exec.Command("docker", "rmi", "-f", tag).Run()
	})

	cat := exec.Command("docker", "run", "--rm", "--entrypoint", "cat", tag, "/app/templates/docs/bd_prelim_design.md")
	body, err := runTimed(cat, 30*time.Second)
	if err != nil {
		t.Fatalf("image missing /app/templates/docs/bd_prelim_design.md: %v\n%s", err, body)
	}
	if !bytes.Contains(body, []byte("系统初步设计方案")) || !bytes.Contains(body, []byte("子系统划分")) {
		t.Fatalf("image template is not the official prelim_design (%d bytes)", len(body))
	}
	ls := exec.Command("docker", "run", "--rm", "--entrypoint", "ls", tag, "/app/configs/agents")
	agents, err := runTimed(ls, 30*time.Second)
	if err != nil {
		t.Fatalf("image missing /app/configs/agents: %v\n%s", err, agents)
	}
	if !bytes.Contains(agents, []byte("writer.md")) {
		t.Fatalf("image configs/agents incomplete: %s", agents)
	}
}

func runTimed(cmd *exec.Cmd, d time.Duration) ([]byte, error) {
	var buf bytes.Buffer
	cmd.Stdout = &buf
	cmd.Stderr = &buf
	if err := cmd.Start(); err != nil {
		return buf.Bytes(), err
	}
	done := make(chan error, 1)
	go func() { done <- cmd.Wait() }()
	select {
	case err := <-done:
		return buf.Bytes(), err
	case <-time.After(d):
		_ = cmd.Process.Kill()
		return buf.Bytes(), os.ErrDeadlineExceeded
	}
}

func readDockerignore(t *testing.T, path string) []string {
	t.Helper()
	raw, err := os.ReadFile(path)
	if err != nil {
		t.Fatal(err)
	}
	return strings.Split(string(raw), "\n")
}

func dockerIgnored(patterns []string, rel string) bool {
	rel = filepath.ToSlash(rel)
	ignored := false
	for _, raw := range patterns {
		p := strings.TrimSpace(raw)
		if p == "" || strings.HasPrefix(p, "#") {
			continue
		}
		negate := false
		if strings.HasPrefix(p, "!") {
			negate = true
			p = strings.TrimPrefix(p, "!")
		}
		if matchDockerPattern(p, rel) {
			ignored = !negate
		}
	}
	return ignored
}

func matchDockerPattern(pattern, rel string) bool {
	pattern = filepath.ToSlash(pattern)
	if pattern == rel {
		return true
	}
	if strings.HasSuffix(pattern, "/**/*.md") {
		prefix := strings.TrimSuffix(pattern, "/**/*.md")
		return strings.HasPrefix(rel, prefix+"/") && strings.HasSuffix(rel, ".md")
	}
	if pattern == "*.md" {
		return strings.HasSuffix(rel, ".md")
	}
	if !strings.Contains(pattern, "/") && !strings.Contains(pattern, "*") {
		return rel == pattern || strings.HasPrefix(rel, pattern+"/")
	}
	ok, _ := filepath.Match(pattern, rel)
	if ok {
		return true
	}
	ok, _ = filepath.Match(pattern, filepath.Base(rel))
	return ok
}