package plugins

import (
	"fmt"

	"verstak/internal/core/nodes"

	lua "github.com/yuin/gopher-lua"
)

// nodeToTable converts a Node to a Lua table.
func nodeToTable(L *lua.LState, n nodeOrErr) *lua.LTable {
	tbl := L.NewTable()
	if n.err != nil {
		return tbl
	}
	tbl.RawSetString("id", lua.LString(n.node.ID))
	tbl.RawSetString("title", lua.LString(n.node.Title))
	tbl.RawSetString("type", lua.LString(n.node.Type))
	tbl.RawSetString("slug", lua.LString(n.node.Slug))
	tbl.RawSetString("sort_order", lua.LNumber(n.node.SortOrder))
	tbl.RawSetString("archived", lua.LBool(n.node.Archived))
	tbl.RawSetString("revision", lua.LNumber(n.node.Revision))
	tbl.RawSetString("created_at", lua.LString(n.node.CreatedAt.Format(timeFormat)))
	tbl.RawSetString("updated_at", lua.LString(n.node.UpdatedAt.Format(timeFormat)))
	if n.node.ParentID != nil {
		tbl.RawSetString("parent_id", lua.LString(*n.node.ParentID))
	}
	if n.node.DeletedAt != nil {
		tbl.RawSetString("deleted_at", lua.LString(n.node.DeletedAt.Format(timeFormat)))
	}
	return tbl
}

// registerNodeAPI registers the verstak.node.* API and returns the table.
func registerNodeAPI(vm *LuaVM) *lua.LTable {
	svc := vm.Services
	if svc == nil || svc.NodeRepo == nil {
		// No services available — return empty table but still register it
		emptyTbl := vm.L.NewTable()
		vm.L.SetGlobal("verstak_node", emptyTbl)
		return emptyTbl
	}
	L := vm.L
	tbl := L.NewTable()

	// verstak.node.get(id) → table or nil
	tbl.RawSetString("get", L.NewFunction(func(L *lua.LState) int {
		id := L.CheckString(1)
		n, err := svc.NodeRepo.GetActive(id)
		if err != nil {
			return pushError(L, err)
		}
		tbl := nodeToTable(L, nodeOrErr{node: n})
		L.Push(tbl)
		return 1
	}))

	// verstak.node.list(parent_id) → array of tables
	tbl.RawSetString("list", L.NewFunction(func(L *lua.LState) int {
		parentID := L.CheckString(1)
		children, err := svc.NodeRepo.ListChildren(parentID, false)
		if err != nil {
			return pushError(L, err)
		}
		arr := L.NewTable()
		for i, n := range children {
			tbl := nodeToTable(L, nodeOrErr{node: &n})
			arr.RawSetInt(i+1, tbl)
		}
		L.Push(arr)
		return 1
	}))

	// verstak.node.create(parent_id, title, type) → table
	tbl.RawSetString("create", L.NewFunction(func(L *lua.LState) int {
		parentID := lua.LNil
		if L.GetTop() >= 1 && L.Get(1) != lua.LNil {
			parentID = L.Get(1)
		}
		title := L.CheckString(2)
		typ := L.OptString(3, "document")
		_ = L.OptString(4, "") // props (reserved)

		var pID *string
		if parentID != lua.LNil {
			s := lua.LVAsString(parentID)
			if s != "" {
				pID = &s
			}
		}
		n, err := svc.NodeRepo.Create(pID, typ, title, 0, "", "")
		if err != nil {
			return pushError(L, err)
		}
		tbl := nodeToTable(L, nodeOrErr{node: n})
		L.Push(tbl)
		return 1
	}))

	// verstak.node.update(id, fields) → success/error
	tbl.RawSetString("update", L.NewFunction(func(L *lua.LState) int {
		id := L.CheckString(1)
		fields := L.CheckTable(2)

		titleVal := fields.RawGetString("title")
		if titleVal != lua.LNil {
			if err := svc.NodeRepo.UpdateTitle(id, lua.LVAsString(titleVal)); err != nil {
				return pushError(L, err)
			}
		}
		L.Push(lua.LBool(true))
		return 1
	}))

	// verstak.node.delete(id) → success/error
	tbl.RawSetString("delete", L.NewFunction(func(L *lua.LState) int {
		id := L.CheckString(1)
		if err := svc.NodeRepo.SoftDelete(id); err != nil {
			return pushError(L, err)
		}
		L.Push(lua.LBool(true))
		return 1
	}))

	// verstak.node.search(query) → array of tables
	tbl.RawSetString("search", L.NewFunction(func(L *lua.LState) int {
		query := L.CheckString(1)
		limit := L.OptInt(2, 20)
		results, err := svc.NodeRepo.Search(query, limit)
		if err != nil {
			return pushError(L, err)
		}
		arr := L.NewTable()
		for i, n := range results {
			tbl := nodeToTable(L, nodeOrErr{node: &n})
			arr.RawSetInt(i+1, tbl)
		}
		L.Push(arr)
		return 1
	}))

	// verstak.node.roots() → array of root-level nodes
	tbl.RawSetString("roots", L.NewFunction(func(L *lua.LState) int {
		roots, err := svc.NodeRepo.ListRoots(false)
		if err != nil {
			return pushError(L, err)
		}
		arr := L.NewTable()
		for i, n := range roots {
			tbl := nodeToTable(L, nodeOrErr{node: &n})
			arr.RawSetInt(i+1, tbl)
		}
		L.Push(arr)
		return 1
	}))

	// verstak.node.meta — sub-table
	metaTbl := L.NewTable()
	metaTbl.RawSetString("get", L.NewFunction(func(L *lua.LState) int {
		nodeID := L.CheckString(1)
		key := L.CheckString(2)
		v, ok, err := svc.NodeRepo.MetaGet(nodeID, key)
		if err != nil {
			return pushError(L, err)
		}
		if !ok {
			L.Push(lua.LNil)
		} else {
			L.Push(lua.LString(v))
		}
		return 1
	}))
	metaTbl.RawSetString("set", L.NewFunction(func(L *lua.LState) int {
		nodeID := L.CheckString(1)
		key := L.CheckString(2)
		value := L.CheckString(3)
		if err := svc.NodeRepo.MetaSet(nodeID, key, value); err != nil {
			return pushError(L, err)
		}
		L.Push(lua.LBool(true))
		return 1
	}))
	metaTbl.RawSetString("list", L.NewFunction(func(L *lua.LState) int {
		nodeID := L.CheckString(1)
		metas, err := svc.NodeRepo.MetaList(nodeID)
		if err != nil {
			return pushError(L, err)
		}
		arr := L.NewTable()
		for i, m := range metas {
			entry := L.NewTable()
			entry.RawSetString("key", lua.LString(m.Key))
			entry.RawSetString("value", lua.LString(m.Value))
			arr.RawSetInt(i+1, entry)
		}
		L.Push(arr)
		return 1
	}))
	tbl.RawSetString("meta", metaTbl)

	// Set the global
	L.SetGlobal("verstak_node", tbl)

	// Also add to the main verstak table if it exists
	mainTbl := L.GetGlobal("verstak")
	if mainTbl != lua.LNil {
		if tbl2, ok := mainTbl.(*lua.LTable); ok {
			tbl2.RawSetString("node", tbl)
		}
	}

	return tbl
}

// nodeOrErr is a helper to keep node + potential error together.
type nodeOrErr struct {
	node *nodes.Node
	err  error
}

// timeFormat for Lua output.
const timeFormat = "2006-01-02T15:04:05Z07:00"

// This function is used in the text below — comment to satisfy unused import.
var _ = fmt.Sprintf