package cabana

import (
	"bytes"
	"context"
	"encoding/json"
	"io/fs"
	"net/http"
	"net/http/httptest"
	"strconv"
	"strings"
	"sync"
	"testing"
	"testing/fstest"

	"git.golem15.com/golem15/summercms/modules/backpack"
	"git.golem15.com/golem15/summercms/modules/bouncer"
	"git.golem15.com/golem15/summercms/modules/pact"
	"git.golem15.com/golem15/summercms/modules/party"
	"gorm.io/gorm"
)

// The D-91 form extension save, show and schema paths on a real Postgres
// database (testcontainers, like newListService): an owner plugin acme.blog
// with the posts controller, and a contributor acme.extra that adds fields
// and stores their values in its own table.

// fePost is the owner's model: columns a and b only.
type fePost struct {
	ID uint   `gorm:"column:id;primaryKey"`
	A  string `gorm:"column:a"`
	B  string `gorm:"column:b"`
}

func (fePost) TableName() string         { return "acme_blog_posts" }
func (*fePost) Fillable() []string       { return []string{"a", "b"} }
func (*fePost) Rules() map[string]string { return map[string]string{} }

// feExtraValue is the contributor's own table: one value per post.
type feExtraValue struct {
	RecordID uint   `gorm:"column:record_id;primaryKey;autoIncrement:false"`
	Value    string `gorm:"column:value"`
}

func (feExtraValue) TableName() string { return "acme_extra_values" }

// fePosts is the owner's admin controller.
type fePosts struct{}

func (fePosts) ID() string                    { return "acme.blog.posts" }
func (fePosts) ModelName() string             { return "Post" }
func (fePosts) ConfigDir() string             { return "controllers/posts" }
func (fePosts) NewRecord() any                { return &fePost{} }
func (fePosts) RequiredPermissions() []string { return []string{"acme.blog.access"} }

// feOwner is the owner plugin; fields is the body of its fields.yaml.
type feOwner struct {
	fields string
}

func (feOwner) ID() string                   { return "acme.blog" }
func (feOwner) Requires() []string           { return nil }
func (feOwner) Register(*backpack.App) error { return nil }
func (feOwner) Boot(*backpack.App) error     { return nil }
func (p feOwner) AdminFS() fs.FS             { return feOwnerFS(p.fields) }
func (feOwner) AdminControllers() []pact.AdminController {
	return []pact.AdminController{fePosts{}}
}

// feOwnerFields is the owner form of the tracer: a and b, no tabs.
const feOwnerFields = "fields:\n    a:\n        type: text\n        label: A\n    b:\n        type: text\n        label: B\n"

func feOwnerFS(fields string) fstest.MapFS {
	return fstest.MapFS{
		"controllers/posts/config_form.yaml": &fstest.MapFile{Data: []byte("name: Post\nform: ~/plugins/acme/blog/models/post/fields.yaml\nmodelClass: Post\n")},
		"controllers/posts/config_list.yaml": &fstest.MapFile{Data: []byte("list: ~/plugins/acme/blog/models/post/columns.yaml\nmodelClass: Post\nrecordsPerPage: 20\ntoolbar:\n    buttons: [create]\n")},
		"models/post/columns.yaml":           &fstest.MapFile{Data: []byte("columns:\n    a:\n        label: A\n")},
		"models/post/fields.yaml":            &fstest.MapFile{Data: []byte(fields)},
	}
}

// feContributor is a plugin that extends other plugins' forms.
type feContributor struct {
	id         string
	requires   []string
	fsys       fstest.MapFS
	types      []pact.FormFieldType
	extensions []pact.AdminActionExtension
}

func (p feContributor) ID() string                           { return p.id }
func (p feContributor) Requires() []string                   { return p.requires }
func (feContributor) Register(*backpack.App) error           { return nil }
func (feContributor) Boot(*backpack.App) error               { return nil }
func (p feContributor) AdminFS() fs.FS                       { return p.fsys }
func (p feContributor) FormFieldTypes() []pact.FormFieldType { return p.types }
func (p feContributor) AdminActionExtensions() []pact.AdminActionExtension {
	return p.extensions
}

var (
	_ party.Plugin                  = feContributor{}
	_ pact.HasAdminActionExtensions = feContributor{}
)

// feCompile runs the boot path: field types, the registry, then the form
// extensions, as Activate does.
func feCompile(plugins ...party.Plugin) (*Registry, error) {
	reg, err := ftCompile(plugins...)
	if err != nil {
		return nil, err
	}
	if err := compileFormExtensions(reg, plugins); err != nil {
		return nil, err
	}
	return reg, nil
}

// feStore is the contributor's storage spy: every Save call's input, the
// owner row as Save read it through the save transaction, and failures to
// return.
type feStore struct {
	mu      sync.Mutex
	saves   []pact.AdminFormSave
	ownerA  []string
	fail    error
	notices map[string][]pact.FormFieldNotice
}

func (s *feStore) save(_ context.Context, in pact.AdminFormSave) (pact.AdminFormSaveResult, error) {
	s.mu.Lock()
	defer s.mu.Unlock()
	s.saves = append(s.saves, in)
	var a string
	if err := in.DB.Raw("SELECT a FROM acme_blog_posts WHERE id = ?", in.ID).Scan(&a).Error; err != nil {
		return pact.AdminFormSaveResult{}, err
	}
	s.ownerA = append(s.ownerA, a)
	if value, ok := in.Values["c"]; ok {
		text, _ := value.(string)
		id, _ := strconv.ParseUint(in.ID, 10, 64)
		row := feExtraValue{RecordID: uint(id), Value: text}
		if err := in.DB.Save(&row).Error; err != nil {
			return pact.AdminFormSaveResult{}, err
		}
	}
	if s.fail != nil {
		return pact.AdminFormSaveResult{}, s.fail
	}
	return pact.AdminFormSaveResult{Notices: s.notices}, nil
}

func (s *feStore) load(_ context.Context, in pact.AdminFormLoad) (map[string]any, error) {
	var row feExtraValue
	err := in.DB.Where("record_id = ?", in.ID).Limit(1).Find(&row).Error
	if err != nil {
		return nil, err
	}
	return map[string]any{"c": row.Value, "a": "never served"}, nil
}

// feExtraFS is the contributor's tree with one fields document.
func feExtraFS(doc string) fstest.MapFS {
	return fstest.MapFS{"extensions/posts.yaml": &fstest.MapFile{Data: []byte(doc)}}
}

// feCall runs one admin request against a controller of svc.
func feCall(t *testing.T, svc *service, principal *bouncer.Principal, controller, method, route, id string, body any) *httptest.ResponseRecorder {
	t.Helper()
	var raw []byte
	if body != nil {
		var err error
		if raw, err = json.Marshal(body); err != nil {
			t.Fatal(err)
		}
	}
	req := httptest.NewRequest(method, "/", bytes.NewReader(raw))
	req.Header.Set("Content-Type", "application/json")
	parts := strings.SplitN(controller, ".", 3)
	req.SetPathValue("vendor", parts[0])
	req.SetPathValue("plugin", parts[1])
	req.SetPathValue("controller", parts[2])
	if id != "" {
		req.SetPathValue("id", id)
	}
	req = req.WithContext(bouncer.WithUser(req.Context(), principal))
	rec := httptest.NewRecorder()
	switch route {
	case "schema":
		svc.formSchema(rec, req)
	case "record":
		switch method {
		case http.MethodPost:
			svc.create(rec, req)
		case http.MethodGet:
			svc.show(rec, req)
		case http.MethodPut:
			svc.update(rec, req)
		default:
			t.Fatalf("method %s", method)
		}
	default:
		t.Fatalf("route %s", route)
	}
	return rec
}

// feSchemaNames is the field name list of a form schema response.
func feSchemaNames(t *testing.T, rec *httptest.ResponseRecorder) []string {
	t.Helper()
	if rec.Code != http.StatusOK {
		t.Fatalf("schema status=%d body=%s", rec.Code, rec.Body.String())
	}
	var out struct {
		Data struct {
			Fields []struct {
				Name string `json:"name"`
				Tab  string `json:"tab"`
			} `json:"fields"`
		} `json:"data"`
	}
	if err := json.Unmarshal(rec.Body.Bytes(), &out); err != nil {
		t.Fatal(err)
	}
	names := make([]string, 0, len(out.Data.Fields))
	for _, field := range out.Data.Fields {
		names = append(names, field.Name)
	}
	return names
}

// feEnv is a Postgres-backed admin service with the owner and contributor.
type feEnv struct {
	db  *gorm.DB
	svc *service
}

func newFEEnv(t *testing.T, plugins ...party.Plugin) feEnv {
	t.Helper()
	_, db := newListService(t)
	if err := db.Migrator().DropTable(&fePost{}, &feExtraValue{}); err != nil {
		t.Fatal(err)
	}
	if err := db.AutoMigrate(&fePost{}, &feExtraValue{}); err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { _ = db.Migrator().DropTable(&fePost{}, &feExtraValue{}) })
	reg, err := feCompile(plugins...)
	if err != nil {
		t.Fatalf("compile: %v", err)
	}
	app := backpack.New(nil)
	if err := app.Publish(db); err != nil {
		t.Fatal(err)
	}
	return feEnv{db: db, svc: &service{app: app, reg: reg}}
}

func (e feEnv) post(t *testing.T, id uint) fePost {
	t.Helper()
	var out fePost
	if err := e.db.First(&out, id).Error; err != nil {
		t.Fatal(err)
	}
	return out
}

func (e feEnv) extra(t *testing.T, id uint) (string, bool) {
	t.Helper()
	var rows []feExtraValue
	if err := e.db.Where("record_id = ?", id).Find(&rows).Error; err != nil {
		t.Fatal(err)
	}
	if len(rows) == 0 {
		return "", false
	}
	return rows[0].Value, true
}

// TestFormExtensionTracer (SC-1, D-91): plugin acme.extra adds field c after
// a on acme.blog's form of a and b. The schema lists a, c, b; an update
// stores a and b in the owner row and c in the contributor's table in the
// same transaction; show serves c; the owner model never gains a c column.
func TestFormExtensionTracer(t *testing.T) {
	store := &feStore{}
	extra := feContributor{
		id:   "acme.extra",
		fsys: feExtraFS("fields:\n    c:\n        type: text\n        label: C\n        after: a\n"),
		extensions: []pact.AdminActionExtension{{
			Controller: "acme.blog.posts",
			Form:       &pact.AdminFormExtension{Fields: "extensions/posts.yaml", Load: store.load, Save: store.save},
		}},
	}
	env := newFEEnv(t, feOwner{fields: feOwnerFields}, extra)

	names := feSchemaNames(t, feCall(t, env.svc, superUser(), "acme.blog.posts", http.MethodGet, "schema", "", nil))
	if strings.Join(names, " ") != "a c b" {
		t.Fatalf("schema fields = %v, want [a c b]", names)
	}

	seed := fePost{A: "A0", B: "B0"}
	if err := env.db.Create(&seed).Error; err != nil {
		t.Fatal(err)
	}
	idText := strconv.FormatUint(uint64(seed.ID), 10)
	rec := feCall(t, env.svc, superUser(), "acme.blog.posts", http.MethodPut, "record", idText, map[string]any{"a": "A1", "b": "B1", "c": "C1"})
	if rec.Code != http.StatusOK {
		t.Fatalf("update status=%d body=%s", rec.Code, rec.Body.String())
	}
	saved := pgFTDecode(t, rec)
	if saved.Data["c"] != "C1" || saved.Data["a"] != "A1" {
		t.Fatalf("update data=%v, want a=A1 and c=C1 served by Load", saved.Data)
	}
	if got := env.post(t, seed.ID); got.A != "A1" || got.B != "B1" {
		t.Fatalf("owner row=%+v", got)
	}
	if value, ok := env.extra(t, seed.ID); !ok || value != "C1" {
		t.Fatalf("contributor row=%q,%v", value, ok)
	}
	if len(store.saves) != 1 || store.saves[0].Created || store.saves[0].ID != idText || store.saves[0].Controller != "acme.blog.posts" {
		t.Fatalf("saves=%+v", store.saves)
	}
	if len(store.saves[0].Values) != 1 || store.saves[0].Values["c"] != "C1" {
		t.Fatalf("Save values=%v, want only c", store.saves[0].Values)
	}
	if store.ownerA[0] != "A1" {
		t.Fatalf("Save read owner a=%q through its DB, want the uncommitted A1 of the same transaction", store.ownerA[0])
	}

	rec = feCall(t, env.svc, superUser(), "acme.blog.posts", http.MethodGet, "record", idText, nil)
	if rec.Code != http.StatusOK {
		t.Fatalf("show status=%d body=%s", rec.Code, rec.Body.String())
	}
	if shown := pgFTDecode(t, rec); shown.Data["c"] != "C1" || shown.Data["a"] != "A1" {
		t.Fatalf("show data=%v", shown.Data)
	}
	if env.db.Migrator().HasColumn(&fePost{}, "c") {
		t.Fatal("the owner table gained a c column")
	}
}