package main

import (
	// External
	"github.com/jmoiron/sqlx"
	werr "git.gibonuddevalla.se/go/wrappederror"

	// Standard
	"time"
	"database/sql"
)

type ChecklistItem struct {
	ID      int
	GroupID int `db:"checklist_group_id"`
	Order   int
	Label   string
	Checked bool
}

type ChecklistGroup struct {
	ID     int
	NodeID int `db:"node_id"`
	Order  int
	Label  string
	Items  []ChecklistItem
}

type Node struct {
	ID          int
	UserID      int `db:"user_id"`
	ParentID    int `db:"parent_id"`
	CryptoKeyID int `db:"crypto_key_id"`
	Name        string
	Content     string
	Updated     time.Time
	Children    []Node
	Crumbs      []Node
	Files       []File
	Complete    bool
	Level       int

	ChecklistGroups []ChecklistGroup

	ContentEncrypted string `db:"content_encrypted" json:"-"`
	Markdown         bool
}

func NodeTree(userID, startNodeID int) (nodes []Node, err error) { // {{{
	var rows *sqlx.Rows
	rows, err = service.Db.Conn.Queryx(`
		WITH RECURSIVE nodetree AS (
			SELECT
				*,
				array[name::text] AS path,
				0 AS level
			FROM node
			WHERE
				user_id = $1 AND
				CASE $2::int
					WHEN 0 THEN parent_id IS NULL
					ELSE        parent_id = $2
				END
			
			UNION ALL			

			SELECT
				n.*,
				path||n.name::text AS path,
				nt.level + 1 AS level
			FROM node n
			INNER JOIN nodetree nt ON n.parent_id = nt.id
		)

		SELECT
			id,
			user_id,
			COALESCE(parent_id, 0) AS parent_id,
			name,
			updated,
			level
		FROM nodetree
		ORDER BY
			path ASC
		`,
		userID,
		startNodeID,
	)
	if err != nil {
		return
	}
	defer rows.Close()

	type resultRow struct {
		Node
		Level int
	}

	nodes = []Node{}
	for rows.Next() {
		node := Node{}
		node.Complete = false
		node.Crumbs = []Node{}
		node.Children = []Node{}
		node.Files = []File{}
		if err = rows.StructScan(&node); err != nil {
			return
		}
		nodes = append(nodes, node)
	}

	return
} // }}}
func RootNode(userID int) (node Node, err error) { // {{{
	var rows *sqlx.Rows
	rows, err = service.Db.Conn.Queryx(`
			SELECT
				id,
				user_id,
				0 AS parent_id,
				name
			FROM node
			WHERE
				user_id = $1 AND
				parent_id IS NULL
		`,
		userID,
	)
	if err != nil {
		return
	}
	defer rows.Close()

	node.Name = "Start"
	node.UserID = userID
	node.Complete = true
	node.Children = []Node{}
	node.Crumbs = []Node{}
	node.Files = []File{}
	for rows.Next() {
		row := Node{}
		if err = rows.StructScan(&row); err != nil {
			return
		}

		node.Children = append(node.Children, Node{
			ID:       row.ID,
			UserID:   row.UserID,
			ParentID: row.ParentID,
			Name:     row.Name,
		})
	}

	return
} // }}}
func RetrieveNode(userID, nodeID int) (node Node, err error) { // {{{
	if nodeID == 0 {
		return RootNode(userID)
	}

	var rows *sqlx.Rows
	rows, err = service.Db.Conn.Queryx(`
		WITH RECURSIVE recurse AS (
			SELECT
				id,
				user_id,
				COALESCE(parent_id, 0) AS parent_id,
				COALESCE(crypto_key_id, 0) AS crypto_key_id,
				name,
				content,
				content_encrypted,
				markdown,
				0 AS level
			FROM node
			WHERE
				user_id = $1 AND
				id = $2
			
			UNION
			
			SELECT
				n.id,
				n.user_id,
				n.parent_id,
				COALESCE(n.crypto_key_id, 0) AS crypto_key_id,
				n.name,
				'' AS content,
				'' AS content_encrypted,
				false AS markdown,
				r.level + 1 AS level
			FROM node n
			INNER JOIN recurse r ON n.parent_id = r.id AND r.level = 0
			WHERE
				n.user_id = $1
		)

		SELECT * FROM recurse ORDER BY level ASC
		`,
		userID,
		nodeID,
	)
	if err != nil {
		return
	}
	defer rows.Close()

	type resultRow struct {
		Node
		Level int
	}

	node = Node{}
	node.Children = []Node{}
	for rows.Next() {
		row := resultRow{}
		if err = rows.StructScan(&row); err != nil {
			return
		}

		if row.Level == 0 {
			node.ID = row.ID
			node.UserID = row.UserID
			node.ParentID = row.ParentID
			node.CryptoKeyID = row.CryptoKeyID
			node.Name = row.Name
			node.Complete = true
			node.Markdown = row.Markdown

			if node.CryptoKeyID > 0 {
				node.Content = row.ContentEncrypted
			} else {
				node.Content = row.Content
			}

			node.retrieveChecklist()
		}

		if row.Level == 1 {
			node.Children = append(node.Children, Node{
				ID:          row.ID,
				UserID:      row.UserID,
				ParentID:    row.ParentID,
				CryptoKeyID: row.CryptoKeyID,
				Name:        row.Name,
			})
		}
	}

	node.Crumbs, err = NodeCrumbs(node.ID)
	node.Files, err = Files(userID, node.ID, 0)

	return
} // }}}
func NodeCrumbs(nodeID int) (nodes []Node, err error) { // {{{
	var rows *sqlx.Rows
	rows, err = service.Db.Conn.Queryx(`
		WITH RECURSIVE nodes AS (
			SELECT
				id,
				COALESCE(parent_id, 0) AS parent_id,
				name
			FROM node
			WHERE
				id = $1

			UNION
			
			SELECT
				n.id,
				COALESCE(n.parent_id, 0) AS parent_id,
				n.name
			FROM node n
			INNER JOIN nodes nr ON n.id = nr.parent_id
		)
		SELECT * FROM nodes
	`, nodeID)
	if err != nil {
		return
	}
	defer rows.Close()

	nodes = []Node{}
	for rows.Next() {
		node := Node{}
		if err = rows.StructScan(&node); err != nil {
			return
		}
		nodes = append(nodes, node)
	}
	return
} // }}}
func CreateNode(userID, parentID int, name string) (node Node, err error) { // {{{
	var rows *sqlx.Rows

	rows, err = service.Db.Conn.Queryx(`
		INSERT INTO node(user_id, parent_id, name)
		VALUES($1, NULLIF($2, 0)::integer, $3)
		RETURNING
			id,
			user_id,
			COALESCE(parent_id, 0) AS parent_id,
			name,
			content
		`,
		userID,
		parentID,
		name,
	)
	if err != nil {
		return
	}
	defer rows.Close()

	for rows.Next() {
		node = Node{}
		if err = rows.StructScan(&node); err != nil {
			return
		}
		node.Children = []Node{}
		node.Files = []File{}
		node.Complete = true
	}

	node.Crumbs, err = NodeCrumbs(node.ID)
	return
} // }}}
func UpdateNode(userID, nodeID, timeOffset int, content string, cryptoKeyID int, markdown bool) (err error) { // {{{
	if nodeID == 0 {
		return
	}

	var timezone string
	row := service.Db.Conn.QueryRow(`SELECT timezone FROM _webservice.user WHERE id=$1`, userID)
	err = row.Scan(&timezone)
	if err != nil {
		err = werr.Wrap(err).WithCode("002-000F")
		return
	}

	var scannedSchedules, dbSchedules, add, remove []Schedule
	scannedSchedules = ScanForSchedules(timezone, content)
	for i := range scannedSchedules {
		scannedSchedules[i].Node.ID = nodeID
		scannedSchedules[i].UserID = userID
	}

	var tsx *sql.Tx
	tsx, err = service.Db.Conn.Begin() 
	if err != nil {
		return
	}

	dbSchedules, err = RetrieveSchedules(userID, nodeID)
	if err != nil {
		tsx.Rollback()
		return
	}

	for _, scanned := range scannedSchedules {
		found := false
		for _, db := range dbSchedules {
			if scanned.IsEqual(db) {
				found = true
				break
			}
		}
		if !found {
			add = append(add, scanned)
		}
	}

	for _, db := range dbSchedules {
		found := false
		for _, scanned := range scannedSchedules {
			if db.IsEqual(scanned) {
				found = true
				break
			}
		}
		if !found {
			remove = append(remove, db)
		}
	}

	for _, event := range remove {
		err = event.Delete(tsx)
		if err != nil {
			tsx.Rollback()
			return
		}
	}

	for _, event := range add {
		err = event.Insert(tsx)
		if err != nil {
			tsx.Rollback()
			return
		}
	}

	if cryptoKeyID > 0 {
		_, err = tsx.Exec(`
			UPDATE node
			SET
				content = '',
				content_encrypted = $1,
				markdown = $5,
				crypto_key_id = CASE $2::int
					WHEN 0 THEN NULL
					ELSE $2
				END
			WHERE
				id = $3 AND
				user_id = $4
			`,
			content,
			cryptoKeyID,
			nodeID,
			userID,
			markdown,
		)
	} else {
		_, err = tsx.Exec(`
			UPDATE node
			SET
				content = $1,
				content_encrypted = '',
				markdown = $5,
				crypto_key_id = CASE $2::int
					WHEN 0 THEN NULL
					ELSE $2
				END
			WHERE
				id = $3 AND
				user_id = $4
			`,
			content,
			cryptoKeyID,
			nodeID,
			userID,
			markdown,
		)
	}
	if err != nil {
		tsx.Rollback()
		return
	}

	err = tsx.Commit()

	return
} // }}}
func RenameNode(userID, nodeID int, name string) (err error) { // {{{
	_, err = service.Db.Conn.Exec(`
		UPDATE node SET name = $1 WHERE user_id = $2 AND id = $3
		`,
		name,
		userID,
		nodeID,
	)
	return
} // }}}
func DeleteNode(userID, nodeID int) (err error) { // {{{
	_, err = service.Db.Conn.Exec(`
		WITH RECURSIVE nodetree AS (
			SELECT
				id, parent_id
			FROM node
			WHERE
				user_id = $1 AND id = $2
				
			UNION
			
			SELECT
				n.id, n.parent_id
			FROM node n
			INNER JOIN nodetree nt ON n.parent_id = nt.id
		)

		DELETE FROM node WHERE id IN (
			SELECT id FROM nodetree
		)`,
		userID,
		nodeID,
	)
	return
} // }}}
func SearchNodes(userID int, search string) (nodes []Node, err error) { // {{{
	nodes = []Node{}
	var rows *sqlx.Rows
	rows, err = service.Db.Conn.Queryx(`
		SELECT
			id,
			user_id,
			COALESCE(parent_id, 0) AS parent_id,
			name,
			updated
		FROM node
		WHERE
			user_id = $1 AND
			crypto_key_id IS NULL AND
			(
				content ~* $2 OR
				name ~* $2
			)
		ORDER BY
			updated DESC
	`, userID, search)
	if err != nil {
		return
	}
	defer rows.Close()

	for rows.Next() {
		node := Node{}
		node.Complete = false
		if err = rows.StructScan(&node); err != nil {
			return
		}
		nodes = append(nodes, node)
	}

	return
} // }}}

func ChecklistGroupAdd(userID, nodeID int, label string) (item ChecklistGroup, err error) { // {{{
	var row *sqlx.Row
	row = service.Db.Conn.QueryRowx(
		`
		INSERT INTO checklist_group(node_id, "order", "label")
		(
			SELECT
				$1,
				MAX("order")+1 AS "order",
				$2 AS "label"
			FROM checklist_group g
			INNER JOIN node n ON g.node_id = n.id
			WHERE
				user_id = $3 AND
				node_id = $1
			GROUP BY
				node_id
		) UNION (
			SELECT
				node.id AS node_id,
				0 AS "order",
				$2 AS "label"
			FROM node
			WHERE
				user_id = $3 AND
				node.id = $1
		)
		ORDER BY "order" DESC
		LIMIT 1
		RETURNING
		*
		`,
		nodeID,
		label,
		userID,
	)
	err = row.StructScan(&item)
	return
} // }}}
func ChecklistGroupLabel(userID, checklistGroupID int, label string) (item ChecklistItem, err error) { // {{{
	_, err = service.Db.Conn.Exec(
		`
		UPDATE checklist_group g
		SET label = $3
		FROM node n
		WHERE
			g.node_id = n.id AND
			n.user_id = $1 AND
			g.id = $2;	
		`,
		userID,
		checklistGroupID,
		label,
	)
	return
} // }}}
func ChecklistGroupItemAdd(userID, checklistGroupID int, label string) (item ChecklistItem, err error) { // {{{
	var row *sqlx.Row
	row = service.Db.Conn.QueryRowx(
		`
		INSERT INTO checklist_item(checklist_group_id, "order", "label")
		(
			SELECT
				checklist_group_id,
				MAX("order")+1 AS "order",
				$1 AS "label"
			FROM checklist_item
			WHERE
				checklist_group_id = $2
			GROUP BY
				checklist_group_id 
		) UNION (
			SELECT $2 AS checklist_group_id, 0 AS "order", $1 AS "label"
		)
		ORDER BY "order" DESC
		LIMIT 1
		RETURNING
		*
		`,
		label,
		checklistGroupID,
	)
	err = row.StructScan(&item)
	return
} // }}}
func ChecklistGroupDelete(userID, checklistGroupID int) (err error) { // {{{
	_, err = service.Db.Conn.Exec(
		`
		DELETE
		FROM checklist_group g
		USING
			node n
		WHERE
			g.id = $2 AND
			g.node_id = n.id AND
			n.user_id = $1
		`,
		userID,
		checklistGroupID,
	)
	return
} // }}}

func ChecklistItemState(userID, checklistItemID int, state bool) (err error) { // {{{
	_, err = service.Db.Conn.Exec(
		`
		UPDATE checklist_item i
		SET checked = $3
		FROM checklist_group g, node n
		WHERE
			i.checklist_group_id = g.id AND
			g.node_id = n.id AND
			n.user_id = $1 AND
			i.id = $2;	
		`,
		userID,
		checklistItemID,
		state,
	)
	return
} // }}}
func ChecklistItemLabel(userID, checklistItemID int, label string) (err error) { // {{{
	_, err = service.Db.Conn.Exec(
		`
		UPDATE checklist_item i
		SET label = $3
		FROM checklist_group g, node n
		WHERE
			i.checklist_group_id = g.id AND
			g.node_id = n.id AND
			n.user_id = $1 AND
			i.id = $2;	
		`,
		userID,
		checklistItemID,
		label,
	)
	return
} // }}}
func ChecklistItemDelete(userID, checklistItemID int) (err error) { // {{{
	_, err = service.Db.Conn.Exec(
		`
		DELETE
		FROM checklist_item i
		USING
			checklist_group g,
			node n
		WHERE
			i.id = $2 AND
			i.checklist_group_id = g.id AND
			g.node_id = n.id AND
			n.user_id = $1
		`,
		userID,
		checklistItemID,
	)
	return
} // }}}
func ChecklistItemMove(userID, checklistItemID, afterItemID int) (err error) { // {{{
	_, err = service.Db.Conn.Exec(
		`
		WITH
		"to" AS (
			SELECT
				i.checklist_group_id AS group_id,
				i."order"
			FROM checklist_item i
			INNER JOIN checklist_group g ON i.checklist_group_id = g.id
			INNER JOIN node n ON g.node_id = n.id
			WHERE
				n.user_id = $1 AND
				i.id = $3
		),

		update_order AS (
			UPDATE checklist_item
			SET
				"order" =
				CASE
					WHEN checklist_item."order" <= "to"."order" THEN checklist_item."order" - 1
					WHEN checklist_item."order"  > "to"."order" THEN checklist_item."order" + 1
				END
			FROM "to"
			WHERE
				checklist_item.id != $2 AND
				checklist_item.checklist_group_id = "to".group_id
		)

		UPDATE checklist_item
		SET
			checklist_group_id = "to".group_id,
			"order" = "to"."order"
		FROM "to"
		WHERE
			checklist_item.id = $2
		`,
		userID,
		checklistItemID,
		afterItemID,
	)
	return
} // }}}

func (node *Node) retrieveChecklist() (err error) { // {{{
	var rows *sqlx.Rows
	rows, err = service.Db.Conn.Queryx(`
		SELECT
			g.id AS group_id,
			g.order AS group_order,
			g.label AS group_label,

			COALESCE(i.id, 0) AS item_id,
			COALESCE(i.order, 0) AS item_order,
			COALESCE(i.label, '') AS item_label,
			COALESCE(i.checked, false) AS checked

		FROM public.checklist_group g
		LEFT JOIN public.checklist_item i ON i.checklist_group_id = g.id
		WHERE
			g.node_id = $1
		ORDER BY
			g.order DESC,
			i.order DESC
	`, node.ID)
	if err != nil {
		return
	}
	defer rows.Close()

	groups := make(map[int]*ChecklistGroup)
	var found bool
	var group *ChecklistGroup
	var item ChecklistItem
	for rows.Next() {
		row := struct {
			GroupID    int    `db:"group_id"`
			GroupOrder int    `db:"group_order"`
			GroupLabel string `db:"group_label"`

			ItemID    int    `db:"item_id"`
			ItemOrder int    `db:"item_order"`
			ItemLabel string `db:"item_label"`
			Checked   bool
		}{}
		err = rows.StructScan(&row)
		if err != nil {
			return
		}

		if group, found = groups[row.GroupID]; !found {
			group = new(ChecklistGroup)
			group.ID = row.GroupID
			group.NodeID = node.ID
			group.Order = row.GroupOrder
			group.Label = row.GroupLabel
			group.Items = []ChecklistItem{}
			groups[group.ID] = group
		}

		item = ChecklistItem{}
		item.ID = row.ItemID
		item.GroupID = row.GroupID
		item.Order = row.ItemOrder
		item.Label = row.ItemLabel
		item.Checked = row.Checked

		if item.ID > 0 {
			group.Items = append(group.Items, item)
		}
	}

	node.ChecklistGroups = []ChecklistGroup{}
	for _, group := range groups {
		node.ChecklistGroups = append(node.ChecklistGroups, *group)
	}

	return
} // }}}

// vim: foldmethod=marker