package activitypub

import (
	"context"
	"encoding/json"
	"fmt"
	"net/http"
	"time"

	webutils "git.mstar.dev/mstar/goutils/http"
	"github.com/rs/zerolog/hlog"
	"gorm.io/gorm"

	"git.mstar.dev/mstar/linstrom/activitypub"
	"git.mstar.dev/mstar/linstrom/config"
	"git.mstar.dev/mstar/linstrom/storage-new"
	"git.mstar.dev/mstar/linstrom/storage-new/dbgen"
	"git.mstar.dev/mstar/linstrom/storage-new/models"
	webshared "git.mstar.dev/mstar/linstrom/web/shared"
)

type Tag struct {
	Type string `json:"type"`
	Href string `json:"href"`
	Name string `json:"name"`
}

type ObjectNote struct {
	// Context should be set, if needed, by the endpoint handler
	Context any `json:"@context,omitempty"`

	// Attributes below set from storage

	Id               string    `json:"id"`
	Type             string    `json:"type"`
	Summary          *string   `json:"summary"`
	InReplyTo        *string   `json:"inReplyTo"`
	Published        time.Time `json:"published"`
	Url              string    `json:"url"`
	AttributedTo     string    `json:"attributedTo"`
	To               []string  `json:"to"`
	CC               []string  `json:"cc"`
	Sensitive        bool      `json:"sensitive"`
	AtomUri          string    `json:"atomUri"`
	InReplyToAtomUri *string   `json:"inReplyToAtomUri"`
	// Conversation     string `json:"conversation"` // FIXME: Uncomment once understood what this field wants
	Content string `json:"content"`
	// ContentMap  map[string]string `json:"content_map"` // TODO: Uncomment once/if support for multiple languages available
	// Attachments []string          `json:"attachments"` // FIXME: Change this to document type
	Tags []Tag `json:"tag"`
	// Replies     any               `json:"replies"`     // FIXME: Change this to collection type embedding first page
	// Likes       any               `json:"likes"`       // FIXME: Change this to collection
	// Shares      any               `json:"shares"`      // FIXME: Change this to collection, is boosts
}

func objectNote(w http.ResponseWriter, r *http.Request) {
	id := r.PathValue("id")
	log := hlog.FromRequest(r)
	note, err := NoteFromStorage(r.Context(), id)
	switch err {
	case gorm.ErrRecordNotFound:
		_ = webutils.ProblemDetailsStatusOnly(w, http.StatusNotFound)
		return
	case nil:
		note.Context = activitypub.BaseLdContext
		data, err := json.Marshal(note)
		if err != nil {
			log.Error().Err(err).Any("activity", note).Msg("Failed to marshal create activity")
			_ = webutils.ProblemDetailsStatusOnly(w, http.StatusInternalServerError)
			return
		}
		w.Header().Add("Content-Type", "application/activity+json")
		_, _ = fmt.Fprint(w, string(data))
	default:
		if storage.HandleReconnectError(err) {
			log.Error().Err(err).Msg("Connection failed, restart attempt started")
		} else {
			log.Error().Err(err).Msg("Failed to get create activity from db")
		}
		_ = webutils.ProblemDetailsStatusOnly(w, http.StatusInternalServerError)
	}
}

func NoteFromStorage(ctx context.Context, id string) (*ObjectNote, error) {
	note, err := dbgen.Note.Where(dbgen.Note.ID.Eq(id)).
		Preload(dbgen.Note.Creator).
		Preload(dbgen.Note.PingRelations).
		Preload(dbgen.Note.Tags).
		First()
	if err != nil {
		return nil, err
	}
	// TODO: Check access level, requires acting user to be included in function signature
	publicUrlPrefix := config.GlobalConfig.General.GetFullPublicUrl()
	data := &ObjectNote{
		Id:           publicUrlPrefix + "/api/activitypub/note/" + id,
		Type:         "Note",
		Published:    note.CreatedAt,
		AttributedTo: publicUrlPrefix + "/api/activitypub/user/" + note.CreatorId,
		Content:      note.RawContent, // FIXME: Escape content
		Url:          publicUrlPrefix + "/@" + note.Creator.Username + "/" + id,
		AtomUri:      publicUrlPrefix + "/api/activitypub/object/" + id,
		Tags:         []Tag{},
	}
	switch note.AccessLevel {
	case models.NOTE_TARGET_PUBLIC:
		data.To = []string{
			"https://www.w3.org/ns/activitystreams#Public",
		}
		data.CC = []string{
			fmt.Sprintf("%s/api/activitypub/user/%s/followers", publicUrlPrefix, note.CreatorId),
		}
	case models.NOTE_TARGET_HOME:
		return nil, fmt.Errorf("home access level not implemented")
	case models.NOTE_TARGET_FOLLOWERS:
		return nil, fmt.Errorf("followers access level not implemented")
	case models.NOTE_TARGET_DM:
		return nil, fmt.Errorf("dm access level not implemented")
	default:
		return nil, fmt.Errorf("unknown access level %v", note.AccessLevel)
	}
	if note.RepliesTo.Valid {
		data.InReplyTo = &note.RepliesTo.String
		data.InReplyToAtomUri = &note.RepliesTo.String
	}
	if note.ContentWarning.Valid {
		data.Summary = &note.ContentWarning.String
		data.Sensitive = true
	}
	for _, ping := range note.PingRelations {
		target, err := dbgen.User.GetById(ping.PingTargetId)
		if err != nil {
			return nil, err
		}
		data.Tags = append(data.Tags, Tag{
			Type: "Mention",
			Href: webshared.UserPublicUrl(target.ID),
			Name: target.Username,
		})
	}
	for _, tag := range note.Tags {
		data.Tags = append(data.Tags, Tag{
			Type: "Hashtag",
			Href: tag.TagUrl,
			Name: tag.Tag,
		})
	}
	return data, nil
}