// SiYuan - Build Your Eternal Digital Garden
// Copyright (c) 2020-present, b3log.org
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

package model

import (
	"errors"
	"fmt"

	"github.com/88250/lute"
	"github.com/88250/lute/ast"
	"github.com/88250/lute/parse"
	"github.com/siyuan-note/siyuan/kernel/sql"
	"github.com/siyuan-note/siyuan/kernel/treenode"
	"github.com/siyuan-note/siyuan/kernel/util"
)

// Block 描述了内容块。
type Block struct {
	Box      string            `json:"box"`
	Path     string            `json:"path"`
	HPath    string            `json:"hPath"`
	ID       string            `json:"id"`
	RootID   string            `json:"rootID"`
	ParentID string            `json:"parentID"`
	Name     string            `json:"name"`
	Alias    string            `json:"alias"`
	Memo     string            `json:"memo"`
	Tag      string            `json:"tag"`
	Content  string            `json:"content"`
	FContent string            `json:"fcontent"`
	Markdown string            `json:"markdown"`
	Folded   bool              `json:"folded"`
	Type     string            `json:"type"`
	SubType  string            `json:"subType"`
	RefText  string            `json:"refText"`
	Defs     []*Block          `json:"-"`    // 当前块引用了这些块，避免序列化 JSON 时产生循环引用
	Refs     []*Block          `json:"refs"` // 当前块被这些块引用
	DefID    string            `json:"defID"`
	DefPath  string            `json:"defPath"`
	IAL      map[string]string `json:"ial"`
	Children []*Block          `json:"children"`
	Depth    int               `json:"depth"`
	Count    int               `json:"count"`
}

func (block *Block) IsContainerBlock() bool {
	switch block.Type {
	case "NodeDocument", "NodeBlockquote", "NodeList", "NodeListItem", "NodeSuperBlock":
		return true
	}
	return false
}

type Path struct {
	ID       string   `json:"id"`                 // 块 ID
	Box      string   `json:"box"`                // 块 Box
	Name     string   `json:"name"`               // 当前路径
	HPath    string   `json:"hPath"`              // 人类可读路径
	Type     string   `json:"type"`               // "path"
	NodeType string   `json:"nodeType"`           // 节点类型
	SubType  string   `json:"subType"`            // 节点子类型
	Blocks   []*Block `json:"blocks,omitempty"`   // 子块节点
	Children []*Path  `json:"children,omitempty"` // 子路径节点
	Depth    int      `json:"depth"`              // 层级深度
	Count    int      `json:"count"`              // 子块计数

	Updated string `json:"updated"` // 更新时间
	Created string `json:"created"` // 创建时间
}

func RecentUpdatedBlocks() (ret []*Block) {
	ret = []*Block{}

	sqlBlocks := sql.QueryRecentUpdatedBlocks()
	if 1 > len(sqlBlocks) {
		return
	}

	ret = fromSQLBlocks(&sqlBlocks, "", 0)
	return
}

func SwapBlockRef(refID, defID string, includeChildren bool) (err error) {
	refTree, err := loadTreeByBlockID(refID)
	if nil != err {
		return
	}
	refNode := treenode.GetNodeInTree(refTree, refID)
	if nil == refNode {
		return
	}
	if ast.NodeListItem == refNode.Parent.Type {
		refNode = refNode.Parent
	}
	defTree, err := loadTreeByBlockID(defID)
	if nil != err {
		return
	}
	sameTree := defTree.ID == refTree.ID
	var defNode *ast.Node
	if !sameTree {
		defNode = treenode.GetNodeInTree(defTree, defID)
	} else {
		defNode = treenode.GetNodeInTree(refTree, defID)
	}
	if nil == defNode {
		return
	}
	var defNodeChildren []*ast.Node
	if ast.NodeListItem == defNode.Parent.Type {
		defNode = defNode.Parent
	} else if ast.NodeHeading == defNode.Type && includeChildren {
		defNodeChildren = treenode.HeadingChildren(defNode)
	}
	if ast.NodeListItem == defNode.Type {
		for c := defNode.FirstChild; nil != c; c = c.Next {
			if ast.NodeList == c.Type {
				defNodeChildren = append(defNodeChildren, c)
			}
		}
	}

	refPivot := parse.NewParagraph()
	refNode.InsertBefore(refPivot)

	if ast.NodeListItem == defNode.Type {
		if ast.NodeListItem == refNode.Type {
			if !includeChildren {
				for _, c := range defNodeChildren {
					refNode.AppendChild(c)
				}
			}
			defNode.InsertAfter(refNode)
			refPivot.InsertAfter(defNode)
		} else {
			newID := ast.NewNodeID()
			li := &ast.Node{ID: newID, Type: ast.NodeListItem, ListData: &ast.ListData{Typ: defNode.Parent.ListData.Typ}}
			li.SetIALAttr("id", newID)
			li.SetIALAttr("updated", newID[:14])
			li.AppendChild(refNode)
			defNode.InsertAfter(li)
			if !includeChildren {
				for _, c := range defNodeChildren {
					li.AppendChild(c)
				}
			}

			newID = ast.NewNodeID()
			list := &ast.Node{ID: newID, Type: ast.NodeList, ListData: &ast.ListData{Typ: defNode.Parent.ListData.Typ}}
			list.SetIALAttr("id", newID)
			list.SetIALAttr("updated", newID[:14])
			list.AppendChild(defNode)
			refPivot.InsertAfter(list)
		}
	} else {
		if ast.NodeListItem == refNode.Type {
			newID := ast.NewNodeID()
			list := &ast.Node{ID: newID, Type: ast.NodeList, ListData: &ast.ListData{Typ: refNode.Parent.ListData.Typ}}
			list.SetIALAttr("id", newID)
			list.SetIALAttr("updated", newID[:14])
			list.AppendChild(refNode)
			defNode.InsertAfter(list)

			newID = ast.NewNodeID()
			li := &ast.Node{ID: newID, Type: ast.NodeListItem, ListData: &ast.ListData{Typ: refNode.Parent.ListData.Typ}}
			li.SetIALAttr("id", newID)
			li.SetIALAttr("updated", newID[:14])
			li.AppendChild(defNode)
			for i := len(defNodeChildren) - 1; -1 < i; i-- {
				defNode.InsertAfter(defNodeChildren[i])
			}
			refPivot.InsertAfter(li)
		} else {
			defNode.InsertAfter(refNode)
			refPivot.InsertAfter(defNode)
			for i := len(defNodeChildren) - 1; -1 < i; i-- {
				defNode.InsertAfter(defNodeChildren[i])
			}
		}
	}
	refPivot.Unlink()

	treenode.ReindexBlockTree(refTree)
	if err = writeJSONQueue(refTree); nil != err {
		return
	}
	if !sameTree {
		treenode.ReindexBlockTree(defTree)
		if err = writeJSONQueue(defTree); nil != err {
			return
		}
	}
	WaitForWritingFiles()
	util.ReloadUI()
	return
}

func GetHeadingDeleteTransaction(id string) (transaction *Transaction, err error) {
	tree, err := loadTreeByBlockID(id)
	if nil != err {
		return
	}

	node := treenode.GetNodeInTree(tree, id)
	if nil == node {
		err = errors.New(fmt.Sprintf(Conf.Language(15), id))
		return
	}

	if ast.NodeHeading != node.Type {
		return
	}

	var nodes []*ast.Node
	nodes = append(nodes, node)
	nodes = append(nodes, treenode.HeadingChildren(node)...)

	transaction = &Transaction{}
	luteEngine := NewLute()
	for _, n := range nodes {
		op := &Operation{}
		op.ID = n.ID
		op.Action = "delete"
		transaction.DoOperations = append(transaction.DoOperations, op)

		op = &Operation{}
		op.ID = n.ID
		if nil != n.Parent {
			op.ParentID = n.Parent.ID
		}
		if nil != n.Previous {
			op.PreviousID = n.Previous.ID
		}
		op.Action = "insert"
		op.Data = lute.RenderNodeBlockDOM(n, luteEngine.ParseOptions, luteEngine.RenderOptions)
		transaction.UndoOperations = append(transaction.UndoOperations, op)
	}
	return
}

func GetHeadingChildrenDOM(id string) (ret string) {
	tree, err := loadTreeByBlockID(id)
	if nil != err {
		return
	}
	heading := treenode.GetNodeInTree(tree, id)
	if nil == heading || ast.NodeHeading != heading.Type {
		return
	}

	nodes := append([]*ast.Node{}, heading)
	children := treenode.HeadingChildren(heading)
	nodes = append(nodes, children...)
	luteEngine := NewLute()
	ret = renderBlockDOMByNodes(nodes, luteEngine)
	return
}

func GetHeadingLevelTransaction(id string, level int) (transaction *Transaction, err error) {
	tree, err := loadTreeByBlockID(id)
	if nil != err {
		return
	}

	node := treenode.GetNodeInTree(tree, id)
	if nil == node {
		err = errors.New(fmt.Sprintf(Conf.Language(15), id))
		return
	}

	if ast.NodeHeading != node.Type {
		return
	}

	hLevel := node.HeadingLevel
	if hLevel == level {
		return
	}

	diff := level - hLevel
	var children, childrenHeadings []*ast.Node
	children = append(children, node)
	children = append(children, treenode.HeadingChildren(node)...)
	for _, c := range children {
		ccH := c.ChildrenByType(ast.NodeHeading)
		childrenHeadings = append(childrenHeadings, ccH...)
	}

	transaction = &Transaction{}
	luteEngine := NewLute()
	for _, c := range childrenHeadings {
		op := &Operation{}
		op.ID = c.ID
		op.Action = "update"
		op.Data = lute.RenderNodeBlockDOM(c, luteEngine.ParseOptions, luteEngine.RenderOptions)
		transaction.UndoOperations = append(transaction.UndoOperations, op)

		c.HeadingLevel += diff
		if 6 < c.HeadingLevel {
			c.HeadingLevel = 6
		} else if 1 > c.HeadingLevel {
			c.HeadingLevel = 1
		}

		op = &Operation{}
		op.ID = c.ID
		op.Action = "update"
		op.Data = lute.RenderNodeBlockDOM(c, luteEngine.ParseOptions, luteEngine.RenderOptions)
		transaction.DoOperations = append(transaction.DoOperations, op)
	}
	return
}

func GetBlockDOM(id string) (ret string) {
	if "" == id {
		return
	}

	tree, err := loadTreeByBlockID(id)
	if nil != err {
		return
	}
	node := treenode.GetNodeInTree(tree, id)
	luteEngine := NewLute()
	ret = lute.RenderNodeBlockDOM(node, luteEngine.ParseOptions, luteEngine.RenderOptions)
	return
}

func GetBlockKramdown(id string) (ret string) {
	if "" == id {
		return
	}

	tree, err := loadTreeByBlockID(id)
	if nil != err {
		return
	}

	addBlockIALNodes(tree, false)
	node := treenode.GetNodeInTree(tree, id)
	luteEngine := NewLute()
	ret = treenode.ExportNodeStdMd(node, luteEngine)
	return
}

func GetBlock(id string) (ret *Block, err error) {
	ret, err = getBlock(id)
	return
}

func getBlock(id string) (ret *Block, err error) {
	if "" == id {
		return
	}

	tree, err := loadTreeByBlockID(id)
	if nil != err {
		return
	}

	node := treenode.GetNodeInTree(tree, id)
	sqlBlock := sql.BuildBlockFromNode(node, tree)
	if nil == sqlBlock {
		return
	}
	ret = fromSQLBlock(sqlBlock, "", 0)
	return
}

func getEmbeddedBlock(embedBlockID string, trees map[string]*parse.Tree, sqlBlock *sql.Block, headingMode int, breadcrumb bool) (block *Block, blockPaths []*BlockPath) {
	tree, _ := trees[sqlBlock.RootID]
	if nil == tree {
		tree, _ = loadTreeByBlockID(sqlBlock.RootID)
	}
	if nil == tree {
		return
	}
	def := treenode.GetNodeInTree(tree, sqlBlock.ID)
	if nil == def {
		return
	}

	var unlinks, nodes []*ast.Node
	ast.Walk(def, func(n *ast.Node, entering bool) ast.WalkStatus {
		if !entering {
			return ast.WalkContinue
		}

		if ast.NodeHeading == n.Type {
			if "1" == n.IALAttr("fold") {
				children := treenode.HeadingChildren(n)
				for _, c := range children {
					unlinks = append(unlinks, c)
				}
			}
		}
		return ast.WalkContinue
	})
	for _, n := range unlinks {
		n.Unlink()
	}
	nodes = append(nodes, def)
	if 0 == headingMode && ast.NodeHeading == def.Type && "1" != def.IALAttr("fold") {
		children := treenode.HeadingChildren(def)
		for _, c := range children {
			if "1" == c.IALAttr("heading-fold") {
				// 嵌入块包含折叠标题时不应该显示其下方块 https://github.com/siyuan-note/siyuan/issues/4765
				continue
			}
			nodes = append(nodes, c)
		}
	}

	b := treenode.GetBlockTree(def.ID)
	if nil == b {
		return
	}

	luteEngine := NewLute()
	luteEngine.RenderOptions.ProtyleContenteditable = false // 不可编辑
	dom := renderBlockDOMByNodes(nodes, luteEngine)
	block = &Block{Box: def.Box, Path: def.Path, HPath: b.HPath, ID: def.ID, Type: def.Type.String(), Content: dom}

	// 位于超级块中的嵌入块不显示面包屑 https://github.com/siyuan-note/siyuan/issues/6258
	inSuperBlock := false
	embedNodeTree, _ := loadTreeByBlockID(embedBlockID)
	if nil != embedNodeTree {
		embedNode := treenode.GetNodeInTree(embedNodeTree, embedBlockID)
		inSuperBlock = nil != embedNode && embedNode.ParentIs(ast.NodeSuperBlock)
	}

	if breadcrumb && !inSuperBlock {
		blockPaths = buildBlockBreadcrumb(def)
	}
	if 1 > len(blockPaths) {
		blockPaths = []*BlockPath{}
	}
	return
}