// Copyright 2016 Documize Inc. <legal@documize.com>. All rights reserved.
//
// This software (Documize Community Edition) is licensed under
// GNU AGPL v3 http://www.gnu.org/licenses/agpl-3.0.en.html
//
// You can operate outside the AGPL restrictions by purchasing
// Documize Enterprise Edition and obtaining a commercial license
// by contacting <sales@documize.com>.
//
// https://documize.com

package document

import (
	"database/sql"
	"encoding/json"
	"io/ioutil"
	"net/http"
	"sort"
	"strings"

	"github.com/documize/community/core/env"
	"github.com/documize/community/core/request"
	"github.com/documize/community/core/response"
	"github.com/documize/community/core/streamutil"
	"github.com/documize/community/core/stringutil"
	"github.com/documize/community/domain"
	"github.com/documize/community/domain/organization"
	"github.com/documize/community/domain/permission"
	indexer "github.com/documize/community/domain/search"
	"github.com/documize/community/domain/store"
	"github.com/documize/community/model/activity"
	"github.com/documize/community/model/audit"
	"github.com/documize/community/model/doc"
	"github.com/documize/community/model/link"
	pm "github.com/documize/community/model/permission"
	"github.com/documize/community/model/search"
	"github.com/documize/community/model/space"
	"github.com/documize/community/model/user"
	"github.com/documize/community/model/workflow"
)

// Handler contains the runtime information such as logging and database.
type Handler struct {
	Runtime *env.Runtime
	Store   *store.Store
	Indexer indexer.Indexer
}

// Get is an endpoint that returns the document-level information for a
// given documentID.
func (h *Handler) Get(w http.ResponseWriter, r *http.Request) {
	method := "document.Get"
	ctx := domain.GetRequestContext(r)

	id := request.Param(r, "documentID")
	if len(id) == 0 {
		response.WriteMissingDataError(w, method, "documentID")
		return
	}

	document, err := h.Store.Document.Get(ctx, id)
	if err == sql.ErrNoRows {
		response.WriteNotFoundError(w, method, id)
		return
	}
	if err != nil {
		response.WriteServerError(w, method, err)
		h.Runtime.Log.Error(method, err)
		return
	}

	if !permission.CanViewSpaceDocument(ctx, *h.Store, document.SpaceID) {
		response.WriteForbiddenError(w)
		return
	}

	// draft mode does not record document views
	if document.Lifecycle == workflow.LifecycleLive {
		ctx.Transaction, err = h.Runtime.Db.Beginx()
		if err != nil {
			response.WriteServerError(w, method, err)
			h.Runtime.Log.Error(method, err)
			return
		}

		err = h.Store.Activity.RecordUserActivity(ctx, activity.UserActivity{
			SpaceID:      document.SpaceID,
			DocumentID:   document.RefID,
			SourceType:   activity.SourceTypeDocument,
			ActivityType: activity.TypeRead})

		if err != nil {
			ctx.Transaction.Rollback()
			h.Runtime.Log.Error(method, err)
			return
		}

		ctx.Transaction.Commit()
	}

	h.Store.Audit.Record(ctx, audit.EventTypeDocumentView)

	response.WriteJSON(w, document)
}

// DocumentLinks is an endpoint returning the links for a document.
func (h *Handler) DocumentLinks(w http.ResponseWriter, r *http.Request) {
	method := "document.DocumentLinks"
	ctx := domain.GetRequestContext(r)

	id := request.Param(r, "documentID")
	if len(id) == 0 {
		response.WriteMissingDataError(w, method, "documentID")
		return
	}

	l, err := h.Store.Link.GetDocumentOutboundLinks(ctx, id)
	if len(l) == 0 {
		l = []link.Link{}
	}
	if err != nil && err != sql.ErrNoRows {
		response.WriteServerError(w, method, err)
		h.Runtime.Log.Error(method, err)
		return
	}

	response.WriteJSON(w, l)
}

// BySpace is an endpoint that returns the documents for given space.
func (h *Handler) BySpace(w http.ResponseWriter, r *http.Request) {
	method := "document.BySpace"
	ctx := domain.GetRequestContext(r)

	spaceID := request.Query(r, "space")
	if len(spaceID) == 0 {
		response.WriteMissingDataError(w, method, "space")
		return
	}

	if !permission.CanViewSpace(ctx, *h.Store, spaceID) {
		response.WriteForbiddenError(w)
		return
	}

	// Get the space as we need to check settings.
	space, err := h.Store.Space.Get(ctx, spaceID)

	// Can user view drafts?
	viewDrafts := permission.CanViewDrafts(ctx, *h.Store, spaceID)

	// If space defaults to drfat documents, then this means
	// user can view drafts as long as they have edit rights.
	canEdit := permission.HasPermission(ctx, *h.Store, spaceID, pm.DocumentEdit)
	if space.Lifecycle == workflow.LifecycleDraft && canEdit {
		viewDrafts = true
	}

	// Get complete list of documents regardless of category permission
	// and versioning.
	documents, err := h.Store.Document.GetBySpace(ctx, spaceID)
	if err != nil {
		response.WriteServerError(w, method, err)
		h.Runtime.Log.Error(method, err)
		return
	}

	// Sort by title.
	sort.Sort(doc.ByName(documents))

	// Remove documents that cannot be seen due to lack of
	// category view/access permission.
	cats, err := h.Store.Category.GetBySpace(ctx, spaceID)
	members, err := h.Store.Category.GetSpaceCategoryMembership(ctx, spaceID)
	filtered := FilterCategoryProtected(documents, cats, members, viewDrafts)

	// Keep the latest version when faced with multiple versions.
	filtered = FilterLastVersion(filtered)

	response.WriteJSON(w, filtered)
}

// Update updates an existing document using the format described
// in NewDocumentModel() encoded as JSON in the request.
func (h *Handler) Update(w http.ResponseWriter, r *http.Request) {
	method := "document.Update"
	ctx := domain.GetRequestContext(r)

	documentID := request.Param(r, "documentID")
	if len(documentID) == 0 {
		response.WriteMissingDataError(w, method, "documentID")
		return
	}

	if !permission.CanChangeDocument(ctx, *h.Store, documentID) {
		response.WriteForbiddenError(w)
		return
	}

	defer streamutil.Close(r.Body)
	body, err := ioutil.ReadAll(r.Body)
	if err != nil {
		response.WriteBadRequestError(w, method, err.Error())
		h.Runtime.Log.Error(method, err)
		return
	}

	d := doc.Document{}
	err = json.Unmarshal(body, &d)
	if err != nil {
		response.WriteBadRequestError(w, method, err.Error())
		h.Runtime.Log.Error(method, err)
		return
	}

	d.RefID = documentID

	ctx.Transaction, err = h.Runtime.Db.Beginx()
	if err != nil {
		response.WriteServerError(w, method, err)
		h.Runtime.Log.Error(method, err)
		return
	}

	// If space changed for document, remove document categories.
	oldDoc, err := h.Store.Document.Get(ctx, documentID)
	if err != nil {
		ctx.Transaction.Rollback()
		response.WriteServerError(w, method, err)
		h.Runtime.Log.Error(method, err)
		return
	}

	if oldDoc.SpaceID != d.SpaceID {
		h.Store.Category.RemoveDocumentCategories(ctx, d.RefID)
		err = h.Store.Document.MoveActivity(ctx, documentID, oldDoc.SpaceID, d.SpaceID)
		if err != nil {
			ctx.Transaction.Rollback()
			response.WriteServerError(w, method, err)
			h.Runtime.Log.Error(method, err)
			return
		}
	}

	err = h.Store.Document.Update(ctx, d)
	if err != nil {
		ctx.Transaction.Rollback()
		response.WriteServerError(w, method, err)
		h.Runtime.Log.Error(method, err)
		return
	}

	// If document part of versioned document group
	// then document name must be applied to all documents
	// in the group.
	if len(d.GroupID) > 0 {
		err = h.Store.Document.UpdateGroup(ctx, d)
		if err != nil {
			ctx.Transaction.Rollback()
			response.WriteServerError(w, method, err)
			h.Runtime.Log.Error(method, err)
			return
		}
	}

	// Detect change in document status/lifecycle.
	if d.Lifecycle != oldDoc.Lifecycle {
		// Record document being marked as archived.
		if d.Lifecycle == workflow.LifecycleArchived {
			h.Store.Activity.RecordUserActivity(ctx, activity.UserActivity{
				SpaceID:      d.SpaceID,
				DocumentID:   documentID,
				SourceType:   activity.SourceTypeDocument,
				ActivityType: activity.TypeArchived})
		}

		// Record document being marked as draft.
		if d.Lifecycle == workflow.LifecycleDraft {
			h.Store.Activity.RecordUserActivity(ctx, activity.UserActivity{
				SpaceID:      d.SpaceID,
				DocumentID:   documentID,
				SourceType:   activity.SourceTypeDocument,
				ActivityType: activity.TypeDraft})
		}

		// Record document being marked as live.
		if d.Lifecycle == workflow.LifecycleLive {
			h.Store.Activity.RecordUserActivity(ctx, activity.UserActivity{
				SpaceID:      d.SpaceID,
				DocumentID:   documentID,
				SourceType:   activity.SourceTypeDocument,
				ActivityType: activity.TypePublished})
		}
	}

	ctx.Transaction.Commit()

	h.Store.Audit.Record(ctx, audit.EventTypeDocumentUpdate)

	// Live document indexed for search.
	if d.Lifecycle == workflow.LifecycleLive {
		a, _ := h.Store.Attachment.GetAttachments(ctx, documentID)
		go h.Indexer.IndexDocument(ctx, d, a)

		pages, _ := h.Store.Page.GetPages(ctx, d.RefID)
		for i := range pages {
			go h.Indexer.IndexContent(ctx, pages[i])
		}
	} else {
		go h.Indexer.DeleteDocument(ctx, d.RefID)
	}

	response.WriteEmpty(w)
}

// Delete is an endpoint that deletes a document specified by documentID.
func (h *Handler) Delete(w http.ResponseWriter, r *http.Request) {
	method := "document.Delete"
	ctx := domain.GetRequestContext(r)

	documentID := request.Param(r, "documentID")
	if len(documentID) == 0 {
		response.WriteMissingDataError(w, method, "documentID")
		return
	}

	doc, err := h.Store.Document.Get(ctx, documentID)
	if err != nil {
		response.WriteServerError(w, method, err)
		h.Runtime.Log.Error(method, err)
		return
	}

	// If locked document then no can do
	if doc.Protection == workflow.ProtectionLock {
		response.WriteForbiddenError(w)
		h.Runtime.Log.Info("attempted action on locked document")
		return
	}

	// If approval workflow then only approvers can delete page
	if doc.Protection == workflow.ProtectionReview {
		approvers, err := permission.GetUsersWithDocumentPermission(ctx, *h.Store, doc.SpaceID, doc.RefID, pm.DocumentApprove)
		if err != nil {
			response.WriteForbiddenError(w)
			h.Runtime.Log.Error(method, err)
			return
		}

		if !user.Exists(approvers, ctx.UserID) {
			response.WriteForbiddenError(w)
			h.Runtime.Log.Info("attempted action on document when not approver")
			return
		}
	}

	// permission check
	if !permission.CanDeleteDocument(ctx, *h.Store, documentID) {
		response.WriteForbiddenError(w)
		return
	}

	ctx.Transaction, err = h.Runtime.Db.Beginx()
	if err != nil {
		response.WriteServerError(w, method, err)
		h.Runtime.Log.Error(method, err)
		return
	}

	_, err = h.Store.Document.Delete(ctx, documentID)
	if err != nil {
		ctx.Transaction.Rollback()
		response.WriteServerError(w, method, err)
		h.Runtime.Log.Error(method, err)
		return
	}

	_, err = h.Store.Pin.DeletePinnedDocument(ctx, documentID)
	if err != nil && err != sql.ErrNoRows {
		ctx.Transaction.Rollback()
		response.WriteServerError(w, method, err)
		h.Runtime.Log.Error(method, err)
		return
	}

	h.Store.Link.MarkOrphanDocumentLink(ctx, documentID)
	h.Store.Link.DeleteSourceDocumentLinks(ctx, documentID)

	// Draft actions are not logged
	if doc.Lifecycle == workflow.LifecycleLive {
		h.Store.Activity.RecordUserActivity(ctx, activity.UserActivity{
			SpaceID:      doc.SpaceID,
			DocumentID:   documentID,
			SourceType:   activity.SourceTypeDocument,
			ActivityType: activity.TypeDeleted})
	}

	err = h.Store.Space.DecrementContentCount(ctx, doc.SpaceID)
	if err != nil {
		ctx.Transaction.Rollback()
		response.WriteServerError(w, method, err)
		h.Runtime.Log.Error(method, err)
		return
	}

	ctx.Transaction.Commit()

	h.Store.Audit.Record(ctx, audit.EventTypeDocumentDelete)

	go h.Indexer.DeleteDocument(ctx, documentID)

	response.WriteEmpty(w)
}

// SearchDocuments endpoint takes a list of keywords and returns a list of
// document references matching those keywords.
func (h *Handler) SearchDocuments(w http.ResponseWriter, r *http.Request) {
	method := "document.SearchDocuments"
	ctx := domain.GetRequestContext(r)

	defer streamutil.Close(r.Body)
	body, err := ioutil.ReadAll(r.Body)
	if err != nil {
		response.WriteBadRequestError(w, method, err.Error())
		h.Runtime.Log.Error(method, err)
		return
	}

	// Get search criteria.
	options := search.QueryOptions{}
	err = json.Unmarshal(body, &options)
	if err != nil {
		response.WriteBadRequestError(w, method, err.Error())
		h.Runtime.Log.Error(method, err)
		return
	}
	options.Keywords = strings.TrimSpace(options.Keywords)

	// Get documents for search criteria.
	results, err := h.Store.Search.Documents(ctx, options)
	if err != nil {
		h.Runtime.Log.Error(method, err)
	}

	// Generate slugs for search URL.
	for key, result := range results {
		results[key].DocumentSlug = stringutil.MakeSlug(result.Document)
		results[key].SpaceSlug = stringutil.MakeSlug(result.Space)
	}

	// Remove documents that cannot be seen due to lack of
	// category view/access permission.
	cats, err := h.Store.Category.GetByOrg(ctx, ctx.UserID)
	members, err := h.Store.Category.GetOrgCategoryMembership(ctx, ctx.UserID)
	filtered := indexer.FilterCategoryProtected(results, cats, members)

	// Record user search history.
	if !options.SkipLog {
		if len(filtered) > 0 {
			go h.recordSearchActivity(ctx, filtered, options.Keywords)
		} else {
			ctx.Transaction, err = h.Runtime.Db.Beginx()
			if err != nil {
				h.Runtime.Log.Error(method, err)
				return
			}

			err = h.Store.Activity.RecordUserActivity(ctx, activity.UserActivity{
				SpaceID:      "",
				DocumentID:   "",
				Metadata:     options.Keywords,
				SourceType:   activity.SourceTypeSearch,
				ActivityType: activity.TypeSearched})

			if err != nil {
				ctx.Transaction.Rollback()
				h.Runtime.Log.Error(method, err)
			}

			ctx.Transaction.Commit()
		}
	}

	h.Store.Audit.Record(ctx, audit.EventTypeSearch)

	response.WriteJSON(w, filtered)
}

// Record search request once per document.
// But only if document is partof shared space at the time of the search.
func (h *Handler) recordSearchActivity(ctx domain.RequestContext, q []search.QueryResult, keywords string) {
	method := "recordSearchActivity"
	var err error
	prev := make(map[string]bool)

	ctx.Transaction, err = h.Runtime.Db.Beginx()
	if err != nil {
		h.Runtime.Log.Error(method, err)
		return
	}

	for i := range q {
		// Empty space ID usually signals private document
		// hence search activity should not be visible to others.
		if len(q[i].SpaceID) == 0 {
			continue
		}
		sp, err := h.Store.Space.Get(ctx, q[i].SpaceID)
		if err != nil || len(sp.RefID) == 0 || sp.Type == space.ScopePrivate {
			continue
		}

		if _, isExisting := prev[q[i].DocumentID]; !isExisting {
			err = h.Store.Activity.RecordUserActivity(ctx, activity.UserActivity{
				SpaceID:      q[i].SpaceID,
				DocumentID:   q[i].DocumentID,
				Metadata:     keywords,
				SourceType:   activity.SourceTypeSearch,
				ActivityType: activity.TypeSearched})

			if err != nil {
				ctx.Transaction.Rollback()
				h.Runtime.Log.Error(method, err)
			}

			prev[q[i].DocumentID] = true
		}
	}

	ctx.Transaction.Commit()
}

// FetchDocumentData returns all document data in single API call.
func (h *Handler) FetchDocumentData(w http.ResponseWriter, r *http.Request) {
	method := "document.FetchDocumentData"
	ctx := domain.GetRequestContext(r)

	id := request.Param(r, "documentID")
	if len(id) == 0 {
		response.WriteMissingDataError(w, method, "documentID")
		return
	}

	// document
	document, err := h.Store.Document.Get(ctx, id)
	if err == sql.ErrNoRows {
		response.WriteNotFoundError(w, method, id)
		return
	}
	if err != nil {
		response.WriteServerError(w, method, err)
		h.Runtime.Log.Error(method, err)
		return
	}

	if !permission.CanViewSpaceDocument(ctx, *h.Store, document.SpaceID) {
		response.WriteForbiddenError(w)
		return
	}

	// Don't serve archived document
	if document.Lifecycle == workflow.LifecycleArchived {
		response.WriteForbiddenError(w)
		return
	}

	// permissions
	perms, err := h.Store.Permission.GetUserSpacePermissions(ctx, document.SpaceID)
	if err != nil && err != sql.ErrNoRows {
		response.WriteServerError(w, method, err)
		h.Runtime.Log.Error(method, err)
		return
	}
	if len(perms) == 0 {
		perms = []pm.Permission{}
	}
	record := pm.DecodeUserPermissions(perms)

	roles, err := h.Store.Permission.GetUserDocumentPermissions(ctx, document.RefID)
	if err != nil && err != sql.ErrNoRows {
		response.WriteServerError(w, method, err)
		h.Runtime.Log.Error(method, err)
		return
	}
	if len(roles) == 0 {
		roles = []pm.Permission{}
	}
	rolesRecord := pm.DecodeUserDocumentPermissions(roles)

	// links
	l, err := h.Store.Link.GetDocumentOutboundLinks(ctx, id)
	if len(l) == 0 {
		l = []link.Link{}
	}
	if err != nil && err != sql.ErrNoRows {
		response.WriteServerError(w, method, err)
		h.Runtime.Log.Error(method, err)
		return
	}

	// spaces
	sp, err := h.Store.Space.GetViewable(ctx)
	if err != nil && err != sql.ErrNoRows {
		response.WriteServerError(w, method, err)
		h.Runtime.Log.Error(method, err)
		return
	}
	if len(sp) == 0 {
		sp = []space.Space{}
	}

	// Get version information for this document.
	v := []doc.Version{}

	if len(document.GroupID) > 0 {
		v, err = h.Store.Document.GetVersions(ctx, document.GroupID)
		if err != nil && err != sql.ErrNoRows {
			response.WriteServerError(w, method, err)
			h.Runtime.Log.Error(method, err)
			return
		}
	}

	// Prepare response.
	data := BulkDocumentData{}
	data.Document = document
	data.Permissions = record
	data.Roles = rolesRecord
	data.Links = l
	data.Spaces = sp
	data.Versions = v

	ctx.Transaction, err = h.Runtime.Db.Beginx()
	if err != nil {
		response.WriteServerError(w, method, err)
		h.Runtime.Log.Error(method, err)
		return
	}

	if document.Lifecycle == workflow.LifecycleLive {
		err = h.Store.Activity.RecordUserActivity(ctx, activity.UserActivity{
			SpaceID:      document.SpaceID,
			DocumentID:   document.RefID,
			SourceType:   activity.SourceTypeDocument,
			ActivityType: activity.TypeRead})

		if err != nil {
			ctx.Transaction.Rollback()
			h.Runtime.Log.Error(method, err)
		}
	}

	ctx.Transaction.Commit()

	h.Store.Audit.Record(ctx, audit.EventTypeDocumentView)

	response.WriteJSON(w, data)
}

// BulkDocumentData represents all data associated for a single document.
// Used by FetchDocumentData() bulk data load call.
type BulkDocumentData struct {
	Document    doc.Document      `json:"document"`
	Permissions pm.Record         `json:"permissions"`
	Roles       pm.DocumentRecord `json:"roles"`
	Spaces      []space.Space     `json:"folders"`
	Links       []link.Link       `json:"links"`
	Versions    []doc.Version     `json:"versions"`
}

// Export returns content as self-enclosed HTML file.
func (h *Handler) Export(w http.ResponseWriter, r *http.Request) {
	method := "document.Export"
	ctx := domain.GetRequestContext(r)

	// Deduce ORG if anon user.
	if len(ctx.OrgID) == 0 {
		ctx.Subdomain = organization.GetSubdomainFromHost(r)
		org, err := h.Store.Organization.GetOrganizationByDomain(ctx.Subdomain)
		if err != nil {
			response.WriteServerError(w, method, err)
			h.Runtime.Log.Error(method, err)
			return
		}
		ctx.OrgID = org.RefID
	}

	defer streamutil.Close(r.Body)
	body, err := ioutil.ReadAll(r.Body)
	if err != nil {
		response.WriteBadRequestError(w, method, err.Error())
		h.Runtime.Log.Error(method, err)
		return
	}

	spec := exportSpec{}
	err = json.Unmarshal(body, &spec)
	if err != nil {
		response.WriteBadRequestError(w, method, err.Error())
		h.Runtime.Log.Error(method, err)
		return
	}

	export, err := BuildExport(ctx, *h.Store, spec)
	if err != nil {
		response.WriteServerError(w, method, err)
		h.Runtime.Log.Error(method, err)
		return
	}

	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	w.WriteHeader(http.StatusOK)
	w.Write([]byte(export))
}