package server

import (
	"context"
	"encoding/json"
	"io"
	"log/slog"
	"net/http"
	"net/http/httptest"
	"os"
	"strings"
	"testing"
	"time"

	"github.com/go-chi/chi/v5"
	"github.com/jackc/pgx/v5/pgxpool"

	"git.fabledsword.com/bvandeusen/minstrel/internal/auth"
	"git.fabledsword.com/bvandeusen/minstrel/internal/config"
	"git.fabledsword.com/bvandeusen/minstrel/internal/db"
	"git.fabledsword.com/bvandeusen/minstrel/internal/db/dbq"
	"git.fabledsword.com/bvandeusen/minstrel/internal/library"
	"git.fabledsword.com/bvandeusen/minstrel/internal/subsonic"
)

func TestHealthz(t *testing.T) {
	s := New(slog.New(slog.NewTextHandler(io.Discard, nil)), nil, nil, subsonic.Config{}, config.EventsConfig{}, config.RecommendationConfig{}, "", config.BrandingConfig{}, nil, nil, nil, library.RunScanConfig{})
	ts := httptest.NewServer(s.Router())
	defer ts.Close()

	resp, err := http.Get(ts.URL + "/healthz")
	if err != nil {
		t.Fatalf("GET /healthz: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if resp.StatusCode != http.StatusOK {
		t.Errorf("status = %d, want 200", resp.StatusCode)
	}
	var body map[string]string
	if err := json.NewDecoder(resp.Body).Decode(&body); err != nil {
		t.Fatalf("decode: %v", err)
	}
	if body["status"] != "ok" {
		t.Errorf("body = %v, want status=ok", body)
	}
}

func TestHealthz_IncludesMinClientVersion(t *testing.T) {
	t.Parallel()
	s := &Server{}
	r := chi.NewRouter()
	r.Get("/healthz", s.handleHealthz)
	ts := httptest.NewServer(r)
	defer ts.Close()

	resp, err := http.Get(ts.URL + "/healthz")
	if err != nil {
		t.Fatalf("GET /healthz: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	var body map[string]string
	if err := json.NewDecoder(resp.Body).Decode(&body); err != nil {
		t.Fatalf("decode: %v", err)
	}
	if body["status"] != "ok" {
		t.Errorf("status: got %q want \"ok\"", body["status"])
	}
	if body["min_client_version"] == "" {
		t.Error("min_client_version is empty; clients can't enforce pairing")
	}
}

func TestRouter_ServesSPAAtRoot(t *testing.T) {
	s := New(slog.New(slog.NewTextHandler(io.Discard, nil)), nil, nil, subsonic.Config{}, config.EventsConfig{}, config.RecommendationConfig{}, "", config.BrandingConfig{}, nil, nil, nil, library.RunScanConfig{})
	ts := httptest.NewServer(s.Router())
	defer ts.Close()

	resp, err := http.Get(ts.URL + "/")
	if err != nil {
		t.Fatalf("GET /: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if resp.StatusCode != http.StatusOK {
		t.Errorf("status = %d, want 200", resp.StatusCode)
	}
	if ct := resp.Header.Get("Content-Type"); !strings.Contains(ct, "text/html") {
		t.Errorf("Content-Type = %q, want text/html*", ct)
	}
}

func TestRouter_DeepLinkFallbackReturnsSPA(t *testing.T) {
	s := New(slog.New(slog.NewTextHandler(io.Discard, nil)), nil, nil, subsonic.Config{}, config.EventsConfig{}, config.RecommendationConfig{}, "", config.BrandingConfig{}, nil, nil, nil, library.RunScanConfig{})
	ts := httptest.NewServer(s.Router())
	defer ts.Close()

	resp, err := http.Get(ts.URL + "/artists/00000000-0000-0000-0000-000000000001")
	if err != nil {
		t.Fatalf("GET deep link: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if resp.StatusCode != http.StatusOK {
		t.Errorf("status = %d, want 200", resp.StatusCode)
	}
	if ct := resp.Header.Get("Content-Type"); !strings.Contains(ct, "text/html") {
		t.Errorf("Content-Type = %q, want text/html*", ct)
	}
}

func TestRouter_APIPathNotSwallowedBySPA(t *testing.T) {
	s := New(slog.New(slog.NewTextHandler(io.Discard, nil)), nil, nil, subsonic.Config{}, config.EventsConfig{}, config.RecommendationConfig{}, "", config.BrandingConfig{}, nil, nil, nil, library.RunScanConfig{})
	ts := httptest.NewServer(s.Router())
	defer ts.Close()

	resp, err := http.Get(ts.URL + "/api/does-not-exist")
	if err != nil {
		t.Fatalf("GET /api/does-not-exist: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if resp.StatusCode != http.StatusNotFound {
		t.Errorf("status = %d, want 404", resp.StatusCode)
	}
	if ct := resp.Header.Get("Content-Type"); strings.Contains(ct, "text/html") {
		t.Errorf("Content-Type = %q; /api/* must never return text/html", ct)
	}
}

func TestRouter_RestPathNotSwallowedBySPA(t *testing.T) {
	s := New(slog.New(slog.NewTextHandler(io.Discard, nil)), nil, nil, subsonic.Config{}, config.EventsConfig{}, config.RecommendationConfig{}, "", config.BrandingConfig{}, nil, nil, nil, library.RunScanConfig{})
	ts := httptest.NewServer(s.Router())
	defer ts.Close()

	resp, err := http.Get(ts.URL + "/rest/does-not-exist")
	if err != nil {
		t.Fatalf("GET /rest/does-not-exist: %v", err)
	}
	defer func() { _ = resp.Body.Close() }()

	if resp.StatusCode != http.StatusNotFound {
		t.Errorf("status = %d, want 404", resp.StatusCode)
	}
	if ct := resp.Header.Get("Content-Type"); strings.Contains(ct, "text/html") {
		t.Errorf("Content-Type = %q; /rest/* must never return text/html", ct)
	}
}

// TestRouter_AdminSubtreeNotShadowed is a regression test for a real bug we
// shipped in 06a1fe1 and didn't catch until M6a: r.Route("/api/admin", ...)
// in server.go was creating a second chi subtree at the same prefix as the
// nested admin Route inside api.Mount. chi.Walk shows both subtrees as
// registered, but runtime routing dispatch only matches one — every admin
// endpoint registered by api.Mount (Lidarr config, quarantine, etc.)
// silently 404'd for authenticated callers in production.
//
// chi.Walk enumeration would NOT have caught this (both branches are in
// the tree). The only reliable check is to make a real authenticated
// request and confirm it reaches a handler — i.e. doesn't fall through
// to the JSON NotFound (404) that signals shadowing.
//
// The existing tests in this file pass nil for pool, which skips api.Mount
// entirely (gated behind `if s.Pool != nil`), so the conflict didn't manifest.
//
// Gated on MINSTREL_TEST_DATABASE_URL like other integration-leaning tests.
func TestRouter_AdminSubtreeNotShadowed(t *testing.T) {
	dsn := os.Getenv("MINSTREL_TEST_DATABASE_URL")
	if dsn == "" {
		t.Skip("MINSTREL_TEST_DATABASE_URL not set")
	}
	if err := db.Migrate(dsn, slog.New(slog.NewTextHandler(io.Discard, nil))); err != nil {
		t.Fatalf("migrate: %v", err)
	}
	pool, err := pgxpool.New(context.Background(), dsn)
	if err != nil {
		t.Fatalf("pool: %v", err)
	}
	t.Cleanup(pool.Close)

	// Seed a test admin user + session so the request actually reaches the
	// inner route lookup (auth-middleware short-circuits don't catch shadowing).
	ctx := context.Background()
	q := dbq.New(pool)
	_, _ = pool.Exec(ctx, "DELETE FROM sessions WHERE user_agent = 'shadowing-test'")
	_, _ = pool.Exec(ctx, "DELETE FROM users WHERE username = 'test-shadowing-admin'")
	user, err := q.CreateUser(ctx, dbq.CreateUserParams{
		Username:     "test-shadowing-admin",
		PasswordHash: "x",
		ApiToken:     "test-shadowing-token",
		IsAdmin:      true,
	})
	if err != nil {
		t.Fatalf("CreateUser: %v", err)
	}
	t.Cleanup(func() { _, _ = pool.Exec(ctx, "DELETE FROM users WHERE id = $1", user.ID) })
	token := "shadow-test-" + time.Now().Format("20060102150405")
	tokenHash := auth.HashSessionToken(token)
	_, err = pool.Exec(ctx,
		"INSERT INTO sessions (user_id, token_hash, user_agent) VALUES ($1, $2, 'shadowing-test')",
		user.ID, tokenHash[:],
	)
	if err != nil {
		t.Fatalf("insert session: %v", err)
	}

	s := New(slog.New(slog.NewTextHandler(io.Discard, nil)), pool,
		stubScanner{}, subsonic.Config{}, config.EventsConfig{}, config.RecommendationConfig{}, "", config.BrandingConfig{}, nil, nil, nil, library.RunScanConfig{})
	ts := httptest.NewServer(s.Router())
	defer ts.Close()

	// Each path is registered by a different package: lidarr/config from
	// api.Mount and admin/scan from server.Router. If chi runtime dispatch
	// only routes one /api/admin subtree, one of these returns 404 — that
	// IS the bug we shipped in 06a1fe1.
	cases := []struct {
		method string
		path   string
		owner  string
	}{
		{http.MethodGet, "/api/admin/lidarr/config", "api.Mount"},
		// /api/admin/scan would actually trigger a real library scan via
		// stubScanner; we don't include it. The lidarr/config path is the
		// canonical regression check.
	}
	for _, tc := range cases {
		req, err := http.NewRequest(tc.method, ts.URL+tc.path, nil)
		if err != nil {
			t.Fatalf("build %s %s: %v", tc.method, tc.path, err)
		}
		req.Header.Set("Authorization", "Bearer "+token)
		resp, err := http.DefaultClient.Do(req)
		if err != nil {
			t.Fatalf("%s %s: %v", tc.method, tc.path, err)
		}
		_ = resp.Body.Close()
		if resp.StatusCode == http.StatusNotFound {
			t.Errorf("%s %s (owner=%s) returned 404 with valid admin auth — route is shadowed",
				tc.method, tc.path, tc.owner)
		}
	}
}

// stubScanner is a no-op ScanTrigger used only to make Server.Router()
// register /api/admin/scan. Its Scan method must never be called by the
// route-presence assertions in this file.
type stubScanner struct{}

func (stubScanner) Scan(_ context.Context, _ func(library.Stats)) (library.Stats, error) {
	panic("stubScanner.Scan called from server_test")
}
