package build

import (
	"bytes"
	"context"
	"errors"
	"fmt"
	"os"
	"path/filepath"
	"strings"
	"sync"
	"testing"

	"git.golem15.com/golem15/summercms/modules/kiosk"
)

// memRegistry is an in-memory Registry that counts its calls.
type memRegistry struct {
	mu       sync.Mutex
	versions map[string][]kiosk.RegistryVersion
	details  map[string]kiosk.RegistryPluginDetail
	calls    []string
	fail     error
}

func (r *memRegistry) List(context.Context, string, string) (kiosk.ListResponse, error) {
	r.mu.Lock()
	defer r.mu.Unlock()
	r.calls = append(r.calls, "list")
	return kiosk.ListResponse{}, r.fail
}

func (r *memRegistry) Plugin(_ context.Context, id string) (kiosk.RegistryPluginDetail, error) {
	r.mu.Lock()
	defer r.mu.Unlock()
	r.calls = append(r.calls, "plugin "+id)
	if r.fail != nil {
		return kiosk.RegistryPluginDetail{}, r.fail
	}
	d, ok := r.details[id]
	if !ok {
		return d, fmt.Errorf("%s is %w at mem", id, kiosk.ErrNotFound)
	}
	return d, nil
}

func (r *memRegistry) Versions(_ context.Context, id string) ([]kiosk.RegistryVersion, error) {
	r.mu.Lock()
	defer r.mu.Unlock()
	r.calls = append(r.calls, "versions "+id)
	if r.fail != nil {
		return nil, r.fail
	}
	v, ok := r.versions[id]
	if !ok {
		return nil, fmt.Errorf("%s is %w at mem", id, kiosk.ErrNotFound)
	}
	return v, nil
}

// add lists id with releases given as version:framework pairs, all in
// module example.test/<name>, requiring reqs at every release.
func (r *memRegistry) add(id string, reqs kiosk.Requires, releases ...string) {
	mod := "example.test/" + pluginName(id)
	r.addIn(id, mod, mod, reqs, releases...)
}

func (r *memRegistry) addIn(id, mod, pkg string, reqs kiosk.Requires, releases ...string) {
	if r.versions == nil {
		r.versions = map[string][]kiosk.RegistryVersion{}
		r.details = map[string]kiosk.RegistryPluginDetail{}
	}
	if _, ok := r.versions[id]; !ok {
		r.versions[id] = []kiosk.RegistryVersion{}
	}
	for _, rel := range releases {
		v, fw, _ := strings.Cut(rel, ":")
		r.versions[id] = append(r.versions[id], kiosk.RegistryVersion{Version: v, Framework: fw, Requires: reqs, Module: mod, Package: pkg})
	}
	d := kiosk.RegistryPluginDetail{}
	d.ID, d.Module, d.Package = id, mod, pkg
	d.Repository = "https://example.test/sm-" + pluginName(id) + "-plugin.git"
	r.details[id] = d
}

// installApp writes a minimal application (summer.yaml and a go.mod that
// requires the framework at framework, without a replace) and returns its
// directory. extra are summer.yaml plugins and go.mod requires to add.
func installApp(t *testing.T, framework string, installed map[string]string) string {
	t.Helper()
	dir := t.TempDir()
	yaml := "# The test application.\nmodule: example.test/app\nbinary: app\nplugins:\n"
	gomod := "module example.test/app\n\ngo 1.27.0\n\nrequire " + frameworkModule + " " + framework + "\n"
	if len(installed) == 0 {
		yaml = "module: example.test/app\nbinary: app\n"
	}
	for _, id := range sortedKeys(kiosk.Requires(installed)) {
		mod := "example.test/" + pluginName(id)
		yaml += "  - id: " + id + "\n    module: " + mod + "\n"
		gomod += "require " + mod + " " + installed[id] + "\n"
	}
	write(t, filepath.Join(dir, manifestName), yaml)
	write(t, filepath.Join(dir, "go.mod"), gomod)
	return dir
}

func planSteps(p *InstallPlan) string {
	var parts []string
	for _, s := range p.Steps {
		parts = append(parts, s.ID+"@"+s.Version)
	}
	return strings.Join(parts, ",")
}

// TestResolveInstall pins the resolution rules of plugin:install against
// an in-memory registry: newest compatible release, pins, framework
// errors, requirement closure and order, installed requirements, cycles,
// offline and disabled registries and refused registry strings.
func TestResolveInstall(t *testing.T) {
	ctx := t.Context()
	plan := func(app, arg string, reg Registry, mutate ...func(*InstallOptions)) (*InstallPlan, string, error) {
		t.Helper()
		var out bytes.Buffer
		opts := InstallOptions{StartDir: app, Arg: arg, Yes: true, Registry: reg, Out: &out}
		for _, m := range mutate {
			m(&opts)
		}
		p, err := PlanInstall(ctx, opts)
		return p, out.String(), err
	}

	t.Run("newest compatible", func(t *testing.T) {
		reg := &memRegistry{}
		reg.add("acme.shop", nil, "v0.3.0:v0.7.0", "v0.10.0:v0.6.0", "v0.2.0:v0.6.0", "v0.1.0:v0.5.0", "v0.4.0-rc.1:v0.5.0")
		app := installApp(t, "v0.6.0", nil)
		p, out, err := plan(app, "acme.shop", reg)
		if err != nil {
			t.Fatalf("plan: %v", err)
		}
		if got := planSteps(p); got != "acme.shop@v0.10.0" {
			t.Errorf("steps = %s", got)
		}
		if p.Framework != "v0.6.0" || p.AppDir != app || p.Steps[0].Mode != ModeModule || p.Steps[0].Module != "example.test/shop" {
			t.Errorf("plan = %+v", p)
		}
		if !strings.Contains(out, "Installing 1 plugin into "+app+" (framework v0.6.0):\n  acme.shop@v0.10.0 (module)\n") {
			t.Errorf("summary:\n%s", out)
		}
	})

	t.Run("pin", func(t *testing.T) {
		reg := &memRegistry{}
		reg.add("acme.shop", nil, "v0.3.0:v0.7.0", "v0.2.0:v0.6.0", "v0.1.0:v0.5.0")
		app := installApp(t, "v0.6.0", nil)
		if p, _, err := plan(app, "acme.shop@v0.1.0", reg); err != nil || planSteps(p) != "acme.shop@v0.1.0" {
			t.Errorf("compatible pin: %v, %v", p, err)
		}
		_, _, err := plan(app, "acme.shop@v0.3.0", reg)
		if err == nil || !strings.Contains(err.Error(), "acme.shop v0.3.0 needs framework v0.7.0 or newer; this application builds against v0.6.0") ||
			!strings.Contains(fullError(err), "go get "+frameworkModule+"@v0.7.0") {
			t.Errorf("incompatible pin: %v (%s)", err, fullError(err))
		}
		_, _, err = plan(app, "acme.shop@v0.9.0", reg)
		if err == nil || !strings.Contains(err.Error(), "no release v0.9.0; available: v0.3.0, v0.2.0, v0.1.0") {
			t.Errorf("unknown pin: %v", err)
		}
	})

	t.Run("no compatible release names the minimum framework", func(t *testing.T) {
		reg := &memRegistry{}
		reg.add("acme.shop", nil, "v0.2.0:v0.9.0", "v0.3.0:v0.8.0")
		app := installApp(t, "v0.6.0", nil)
		_, _, err := plan(app, "acme.shop", reg)
		if err == nil || !strings.Contains(err.Error(), "acme.shop v0.3.0 needs framework v0.8.0 or newer") {
			t.Errorf("err = %v, want the newest release's framework named", err)
		}
		empty := &memRegistry{}
		empty.add("acme.shop", nil)
		if _, _, err := plan(app, "acme.shop", empty); err == nil || !strings.Contains(err.Error(), "has no release in the registry") {
			t.Errorf("no releases: %v", err)
		}
	})

	t.Run("requirement closure in dependency order", func(t *testing.T) {
		reg := &memRegistry{}
		reg.add("acme.shop", kiosk.Requires{"acme.user": "v0.1.0", "acme.payment": "v0.2.0"}, "v0.1.0:v0.6.0")
		reg.add("acme.payment", kiosk.Requires{"acme.user": "v0.1.2"}, "v0.3.0:v0.6.0", "v0.2.0:v0.6.0")
		reg.add("acme.user", nil, "v0.1.5:v0.7.0", "v0.1.3:v0.6.0", "v0.1.0:v0.5.0")
		app := installApp(t, "v0.6.0", nil)
		p, out, err := plan(app, "acme.shop", reg)
		if err != nil {
			t.Fatalf("plan: %v", err)
		}
		if got := planSteps(p); got != "acme.user@v0.1.3,acme.payment@v0.3.0,acme.shop@v0.1.0" {
			t.Errorf("steps = %s", got)
		}
		if !strings.Contains(out, "Installing 3 plugins") {
			t.Errorf("summary:\n%s", out)
		}
	})

	t.Run("requirement minimum above the newest compatible release", func(t *testing.T) {
		reg := &memRegistry{}
		reg.add("acme.shop", kiosk.Requires{"acme.user": "v0.2.0"}, "v0.1.0:v0.6.0")
		reg.add("acme.user", nil, "v0.2.0:v0.7.0", "v0.1.9:v0.6.0")
		app := installApp(t, "v0.6.0", nil)
		_, _, err := plan(app, "acme.shop", reg)
		if err == nil || !strings.Contains(err.Error(), "acme.user v0.2.0 needs framework v0.7.0") {
			t.Errorf("err = %v", err)
		}
		reg.add("acme.lonely", kiosk.Requires{"acme.user": "v0.5.0"}, "v0.1.0:v0.6.0")
		_, _, err = plan(app, "acme.lonely", reg)
		if err == nil || !strings.Contains(err.Error(), "acme.user has no release at or above the required minimum v0.5.0") {
			t.Errorf("err = %v", err)
		}
	})

	t.Run("plugins of one module share a release", func(t *testing.T) {
		reg := &memRegistry{}
		reg.addIn("acme.pg", "example.test/pg", "example.test/pg", nil, "v0.2.0:v0.6.0", "v0.1.0:v0.6.0")
		reg.addIn("acme.pgsubs", "example.test/pg", "example.test/pg/subs", kiosk.Requires{"acme.pg": ""}, "v0.2.0:v0.6.0", "v0.1.0:v0.6.0")
		app := installApp(t, "v0.6.0", nil)
		p, _, err := plan(app, "acme.pgsubs@v0.1.0", reg)
		if err != nil {
			t.Fatalf("plan: %v", err)
		}
		if got := planSteps(p); got != "acme.pg@v0.1.0,acme.pgsubs@v0.1.0" {
			t.Errorf("steps = %s, want both at the pinned module release", got)
		}
	})

	t.Run("installed requirements", func(t *testing.T) {
		reg := &memRegistry{}
		reg.add("acme.shop", kiosk.Requires{"acme.user": "v0.1.2"}, "v0.1.0:v0.6.0")
		reg.add("acme.user", nil, "v0.1.3:v0.6.0")
		old := installApp(t, "v0.6.0", map[string]string{"acme.user": "v0.1.1"})
		_, _, err := plan(old, "acme.shop", reg)
		if err == nil || !strings.Contains(err.Error(), "acme.shop needs acme.user v0.1.2 or newer, but the application has v0.1.1") ||
			!strings.Contains(fullError(err), "plugin:update acme.user") {
			t.Errorf("too old: %v (%s)", err, fullError(err))
		}
		fresh := installApp(t, "v0.6.0", map[string]string{"acme.user": "v0.1.2"})
		p, _, err := plan(fresh, "acme.shop", reg)
		if err != nil || planSteps(p) != "acme.shop@v0.1.0" {
			t.Errorf("installed at the minimum: %v, %v", p, err)
		}
		_, _, err = plan(fresh, "acme.user", reg)
		if err == nil || !strings.Contains(err.Error(), "already in summer.yaml") || !strings.Contains(fullError(err), "plugin:update acme.user") {
			t.Errorf("installing an installed plugin: %v", err)
		}
	})

	t.Run("cycle", func(t *testing.T) {
		reg := &memRegistry{}
		reg.add("acme.a", kiosk.Requires{"acme.b": ""}, "v0.1.0:v0.6.0")
		reg.add("acme.b", kiosk.Requires{"acme.c": ""}, "v0.1.0:v0.6.0")
		reg.add("acme.c", kiosk.Requires{"acme.a": ""}, "v0.1.0:v0.6.0")
		_, _, err := plan(installApp(t, "v0.6.0", nil), "acme.a", reg)
		if err == nil || !strings.Contains(err.Error(), "dependency cycle in the registry data: acme.a -> acme.b -> acme.c -> acme.a") {
			t.Errorf("err = %v", err)
		}
	})

	t.Run("offline and disabled", func(t *testing.T) {
		reg := &memRegistry{}
		reg.add("acme.shop", nil, "v0.1.0:v0.6.0")
		app := installApp(t, "v0.6.0", nil)
		_, _, err := plan(app, "acme.shop", reg, func(o *InstallOptions) { o.Offline = true })
		if err == nil || !strings.Contains(err.Error(), "--offline makes no registry calls") || !strings.Contains(fullError(err), "plugin:install <git-url>") {
			t.Errorf("offline: %v (%s)", err, fullError(err))
		}
		if len(reg.calls) != 0 {
			t.Errorf("offline made registry calls: %v", reg.calls)
		}
		_, _, err = plan(app, "acme.shop", nil)
		if err == nil || !strings.Contains(err.Error(), "plugins.registry_url is empty") {
			t.Errorf("disabled: %v", err)
		}
		reg.fail = errors.New("connection refused")
		_, _, err = plan(app, "acme.shop", reg)
		if err == nil || !strings.Contains(err.Error(), "connection refused") {
			t.Errorf("registry down: %v", err)
		}
	})

	t.Run("refused registry strings", func(t *testing.T) {
		app := installApp(t, "v0.6.0", nil)
		cases := map[string]struct {
			mod, pkg string
			reqs     kiosk.Requires
			release  string
			want     string
		}{
			"module flag":     {"-modfile=/tmp/x", "-modfile=/tmp/x", nil, "v0.1.0:v0.6.0", "module"},
			"module shell":    {"example.test/x;rm", "example.test/x;rm", nil, "v0.1.0:v0.6.0", "module"},
			"package outside": {"example.test/x", "example.test/y", nil, "v0.1.0:v0.6.0", "not inside module"},
			"required id":     {"example.test/x", "example.test/x", kiosk.Requires{"Bad ID": ""}, "v0.1.0:v0.6.0", "refused"},
			"version":         {"example.test/x", "example.test/x", nil, "v0.1:v0.6.0", "has no release in the registry"},
		}
		for name, c := range cases {
			reg := &memRegistry{}
			reg.addIn("acme.x", c.mod, c.pkg, c.reqs, c.release)
			_, _, err := plan(app, "acme.x", reg)
			if err == nil || !strings.Contains(err.Error(), c.want) {
				t.Errorf("%s: err = %v, want %q", name, err, c.want)
			}
		}
		for _, arg := range []string{"", "acme", "Acme.Shop", "acme.shop@latest", "acme.shop@v1", "acme.shop@v1.0.0-rc.1", "-x.y"} {
			if _, _, err := plan(app, arg, &memRegistry{}); err == nil {
				t.Errorf("arg %q accepted", arg)
			}
		}
	})

	t.Run("prompt", func(t *testing.T) {
		reg := &memRegistry{}
		reg.add("acme.shop", nil, "v0.1.0:v0.6.0")
		app := installApp(t, "v0.6.0", nil)
		before, _ := os.ReadFile(filepath.Join(app, manifestName))
		_, out, err := plan(app, "acme.shop", reg, func(o *InstallOptions) { o.Yes = false })
		if err == nil || !strings.Contains(err.Error(), "pass --yes") || !strings.Contains(out, "acme.shop@v0.1.0 (module)") {
			t.Errorf("non-interactive: %v\n%s", err, out)
		}
		var question string
		_, _, err = plan(app, "acme.shop", reg, func(o *InstallOptions) {
			o.Yes, o.Interactive = false, true
			o.Confirm = func(q string) (bool, error) { question = q; return false, nil }
		})
		if !errors.Is(err, ErrCancelled) || question != "Install 1 plugin?" {
			t.Errorf("declined: %v, asked %q", err, question)
		}
		_, _, err = plan(app, "acme.shop", reg, func(o *InstallOptions) {
			o.Yes, o.Interactive = false, true
			o.Confirm = func(string) (bool, error) { return false, errors.New("tty closed") }
		})
		if err == nil || !strings.Contains(err.Error(), "tty closed") {
			t.Errorf("prompt error: %v", err)
		}
		if after, _ := os.ReadFile(filepath.Join(app, manifestName)); !bytes.Equal(before, after) {
			t.Error("planning changed summer.yaml")
		}
	})

	t.Run("not an application", func(t *testing.T) {
		if _, _, err := plan(t.TempDir(), "acme.shop", &memRegistry{}); err == nil {
			t.Error("PlanInstall outside an application succeeded")
		}
	})

	t.Run("apply refuses an empty or tampered plan", func(t *testing.T) {
		if err := ApplyInstall(ctx, nil, nil); err == nil {
			t.Error("ApplyInstall(nil) succeeded")
		}
		bad := &InstallPlan{AppDir: t.TempDir(), Steps: []InstallStep{{ID: "acme.x", Version: "v0.1.0", Module: "-x", Package: "-x", Mode: ModeModule}}}
		if err := ApplyInstall(ctx, bad, nil); err == nil || !strings.Contains(err.Error(), "refused") {
			t.Errorf("tampered plan: %v", err)
		}
		mode := &InstallPlan{AppDir: t.TempDir(), Steps: []InstallStep{{ID: "acme.x", Version: "v0.1.0", Module: "example.test/x", Package: "example.test/x", Mode: "zip"}}}
		if err := ApplyInstall(ctx, mode, nil); err == nil || !strings.Contains(err.Error(), "unknown install mode") {
			t.Errorf("unknown mode: %v", err)
		}
	})
}

func TestAskToProceed(t *testing.T) {
	yes := func(string) (bool, error) { return true, nil }
	if err := askToProceed(true, false, nil, "q"); err != nil {
		t.Errorf("--yes: %v", err)
	}
	if err := askToProceed(false, false, yes, "q"); err == nil || !strings.Contains(err.Error(), "--yes") {
		t.Errorf("non-interactive: %v", err)
	}
	if err := askToProceed(false, true, nil, "q"); err == nil || !strings.Contains(err.Error(), "--yes") {
		t.Errorf("interactive without a prompt: %v", err)
	}
	if err := askToProceed(false, true, yes, "q"); err != nil {
		t.Errorf("accepted: %v", err)
	}
}