package tableDB

import (
	"fmt"
	"strings"
	"time"

	"apigo.cc/go/cast"
	"apigo.cc/go/db"
)

// Table provides an AI-friendly interface for interacting with structured data or schema.
type Table struct {
	Name       string
	userID     string
	db         *db.DB
	app        *TableDB
	constraint map[string]any
}

// NewTable creates a new Table instance. Handles ":Field" suffix.
func NewTable(name string, app *TableDB) *Table {
	actualName := name
	var constraint map[string]any

	if strings.HasSuffix(name, ":Field") {
		tableName := strings.TrimSuffix(name, ":Field")
		actualName = "_Field"
		// lookup table_id
		res := app.base.Query("SELECT id FROM `_Table` WHERE name = ? LIMIT 1", tableName)
		if res.Error == nil {
			rec := res.MapOnR1()
			if len(rec) > 0 {
				constraint = map[string]any{"tableId": cast.String(rec["id"])}
			}
		}
	}

	return &Table{
		Name:       actualName,
		userID:     app.userID,
		db:         app.base,
		app:        app,
		constraint: constraint,
	}
}

func (t *Table) checkAuth(id string, action string) error {
	if t.userID == SystemUserID {
		return nil
	}

	if action == "write" && (t.Name == "_Policy" || t.Name == "_Backup") {
		return fmt.Errorf("permission denied for %s", t.Name)
	}

	tableRec := GlobalCache.GetTable(t.Name)
	enableRLS := false
	if tableRec != nil {
		enableRLS = cast.Bool(tableRec["enableRLS"])
	}

	if !enableRLS && !strings.HasPrefix(t.Name, "_") {
		return nil
	}

	policies := GlobalCache.GetFlatPolicies(t.userID, t.Name, action)
	hasFullAccess := false
	for _, p := range policies {
		if p.Condition == "" {
			hasFullAccess = true
			break
		}
	}
	if hasFullAccess {
		return nil
	}

	// 构建合并查询：一次性判断 Creator 和 所有 Conditions
	var authConditions []string
	var authArgs []any

	// 1. 追加 Creator 检查
	hasCreator := true

	if hasCreator {
		authConditions = append(authConditions, "`creator` = ?")
		authArgs = append(authArgs, t.userID)
	}

	// 2. 追加 Policy Conditions
	for _, p := range policies {
		if p.Condition != "" {
			authConditions = append(authConditions, "("+p.Condition+")")
			authArgs = append(authArgs, p.ConditionArgs...)
		}
	}

	// 3. 组装并执行终极 1-RTT 查询
	if len(authConditions) > 0 {
		authPart := "(" + strings.Join(authConditions, " OR ") + ")"
		checkSQL := fmt.Sprintf("SELECT 1 FROM `%s` WHERE id = ? AND %s LIMIT 1", t.Name, authPart)

		finalArgs := append([]any{id}, authArgs...)
		checkRes := t.db.Query(checkSQL, finalArgs...)
		if len(checkRes.MapOnR1()) > 0 {
			return nil // 验证通过！
		}
	}

	return fmt.Errorf("permission denied for %s record %s", t.Name, id)
}

func (t *Table) appendAuthAndConstraint(whereStr string, args []any) (string, []any, error) {
	if t.constraint != nil {
		for k, v := range t.constraint {
			if whereStr != "" {
				whereStr += fmt.Sprintf(" AND %s = ?", k)
			} else {
				whereStr = fmt.Sprintf("%s = ?", k)
			}
			args = append(args, v)
		}
	}

	if t.userID == SystemUserID {
		return whereStr, args, nil
	}

	tableRec := GlobalCache.GetTable(t.Name)
	enableRLS := false
	if tableRec != nil {
		enableRLS = cast.Bool(tableRec["enableRLS"])
	}

	if !enableRLS && !strings.HasPrefix(t.Name, "_") {
		return whereStr, args, nil
	}

	policies := GlobalCache.GetFlatPolicies(t.userID, t.Name, "read")
	hasFullAccess := false
	for _, p := range policies {
		if p.Condition == "" {
			hasFullAccess = true
			break
		}
	}
	if hasFullAccess {
		return whereStr, args, nil
	}

	// Build dynamic SQL
	var authConditions []string
	var authArgs []any

	// Check creator field
	hasCreator := true

	if hasCreator {
		authConditions = append(authConditions, "`creator` = ?")
		authArgs = append(authArgs, t.userID)
	}

	for _, p := range policies {
		if p.Condition != "" {
			authConditions = append(authConditions, "("+p.Condition+")")
			authArgs = append(authArgs, p.ConditionArgs...)
		}
	}

	authPart := "0"
	if len(authConditions) > 0 {
		authPart = "(" + strings.Join(authConditions, " OR ") + ")"
		args = append(args, authArgs...)
	}

	if whereStr != "" {
		whereStr = "(" + whereStr + ") AND " + authPart
	} else {
		whereStr = authPart
	}

	return whereStr, args, nil
}

func (t *Table) reconstructAndSyncSchema() error {
	tables := t.db.Query("SELECT * FROM `_Table`").MapResults()
	fields := t.db.Query("SELECT * FROM `_Field` ORDER BY tableId").MapResults()

	fieldMap := make(map[string][]map[string]any)
	for _, f := range fields {
		tid := cast.String(f["tableId"])
		fieldMap[tid] = append(fieldMap[tid], f)
	}

	var sb strings.Builder
	for _, tbl := range tables {
		name := cast.String(tbl["name"])
		if name == "" {
			continue
		}

		tid := cast.String(tbl["id"])
		tblFields := fieldMap[tid]
		if len(tblFields) == 0 {
			continue // Skip tables with no fields to avoid SQL errors
		}

		memo := cast.String(tbl["memo"])
		sb.WriteString(name + " SD")
		if memo != "" {
			sb.WriteString(" //" + strings.ReplaceAll(memo, "\n", " "))
		}
		sb.WriteString("\n")

		// Always ensure standard fields are present with appropriate indices
		sb.WriteString("  id c10 PK\n")
		sb.WriteString("  createTime bi I\n")
		sb.WriteString("  creator v64\n")
		sb.WriteString("  updateTime bi I\n")
		sb.WriteString("  updater v64\n")

		for _, f := range tblFields {
			fname := cast.String(f["name"])
			if fname == "id" || fname == "createTime" || fname == "creator" || fname == "updateTime" || fname == "updater" {
				continue
			}
			ftype := cast.String(f["type"])
			if ftype == "" {
				ftype = "v255"
			}
			isIndex := cast.Bool(f["isIndex"]) || cast.Int(f["isIndex"]) == 1
			fmemo := cast.String(f["memo"])

			sb.WriteString("  " + fname + " " + ftype)
			if isIndex {
				sb.WriteString(" I")
			}
			if fmemo != "" {
				sb.WriteString(" //" + strings.ReplaceAll(fmemo, "\n", " "))
			}
			sb.WriteString("\n")
		}
		sb.WriteString("\n")
	}

	err := t.db.Sync(sb.String())
	if err != nil {
		return err
	}
	return GlobalCache.Load(t.app)
}

// Set performs an upsert of one or more records.
func (t *Table) Set(data ...any) error {
	if t.userID == "" {
		return fmt.Errorf("authentication required")
	}

	metaTouched := false
	var updatedRows []map[string]any

	// Pre-fetch schema context for business tables
	var tableSchema *TableSchema
	var fields []FieldSchema
	tableRec := GlobalCache.GetTable(t.Name)
	if tableRec != nil {
		cast.Convert(&tableSchema, tableRec)
		fields = GlobalCache.GetFields(tableSchema.ID)
	}

	for _, d := range data {
		record := make(map[string]any)
		cast.Convert(&record, d)

		if t.constraint != nil {
			for k, v := range t.constraint {
				record[k] = v
			}
		}

		if t.app.hooks.OnUpdatingRow != nil && t.Name != "_Table" && t.Name != "_Field" {
			if err := t.app.hooks.OnUpdatingRow(record, tableSchema, fields); err != nil {
				return err
			}
		}

		idVal := record["id"]
		var isInsert bool
		if idVal == nil || cast.String(idVal) == "" {
			isInsert = true
		} else {
			idStr := cast.String(idVal)
			res := t.db.Query(fmt.Sprintf("SELECT id FROM `%s` WHERE id = ? LIMIT 1", t.Name), idStr)
			rec := res.MapOnR1()
			if rec != nil && len(rec) > 0 {
				if err := t.checkAuth(idStr, "write"); err != nil {
					return err
				}
				isInsert = false
			} else {
				isInsert = true
			}
		}

		// Always update updateTime and updater
		record["updateTime"] = time.Now().UnixMilli()
		record["updater"] = t.userID

		var err error
		if isInsert {
			record["createTime"] = record["updateTime"]
			if t.userID != SystemUserID {
				if t.Name == "_Policy" || t.Name == "_Backup" {
					return fmt.Errorf("permission denied for %s", t.Name)
				}
				record["creator"] = t.userID
			} else {
				if record["creator"] == nil {
					record["creator"] = t.userID
				}
			}
			err = t.db.Insert(t.Name, record).Error
		} else {
			// Prevent overwriting CreateTime and Creator on update
			delete(record, "createTime")
			delete(record, "creator")
			err = t.db.Update(t.Name, record, "id = ?", cast.String(record["id"])).Error
		}

		if err != nil {
			return err
		}

		if t.Name == "_Table" || t.Name == "_Field" || t.Name == "_Policy" {
			metaTouched = true
			if t.Name == "_Table" {
				if isInsert && t.app.hooks.OnCreatedTable != nil {
					var ts TableSchema
					cast.Convert(&ts, record)
					t.app.hooks.OnCreatedTable(&ts)
				}
			} else if t.Name == "_Field" {
				if t.app.hooks.OnUpdatedField != nil {
					var fs FieldSchema
					cast.Convert(&fs, record)
					// Look up table schema
					var fts *TableSchema
					GlobalCache.lock.RLock()
					tableName := GlobalCache.TableIDMap[fs.TableID]
					fTableRec := GlobalCache.Tables[tableName]
					GlobalCache.lock.RUnlock()
					if fTableRec != nil {
						cast.Convert(&fts, fTableRec)
					}
					t.app.hooks.OnUpdatedField(fts, &fs)
				}
			}
		} else {
			updatedRows = append(updatedRows, record)
		}
	}

	if metaTouched {
		if t.Name != "_Policy" {
			_ = t.reconstructAndSyncSchema()
		}
		_ = GlobalCache.Load(t.app)
	}

	if len(updatedRows) > 0 && t.app.hooks.OnUpdatedRows != nil {
		t.app.hooks.OnUpdatedRows(updatedRows, tableSchema, fields)
	}

	return nil
}

// SetField adds or updates one or more fields. If table doesn't exist, it will be created.
func (t *Table) SetField(fields ...FieldSchema) error {
	if t.userID == "" {
		return fmt.Errorf("authentication required")
	}

	// 1. Ensure table exists in _Table
	tableRec := GlobalCache.GetTable(t.Name)
	if tableRec == nil {
		// Create table entry
		err := t.app.SetTable(TableSchema{Name: t.Name})
		if err != nil {
			return err
		}

		tableRec = GlobalCache.GetTable(t.Name)
		if tableRec == nil {
			return fmt.Errorf("failed to create table entry for %s", t.Name)
		}

		// Automatically add default ID field to metadata
		_ = t.app.Table(t.Name + ":Field").Set(map[string]any{
			"name":    "id",
			"type":    "c10",
			"isIndex": 1,
			"memo":    "Primary Key",
		})
	}

	// 2. Prepare field records
	fieldTable := t.app.Table(t.Name + ":Field")
	var fieldRecords []any
	for _, f := range fields {
		fRecord := map[string]any{
			"name":     f.Name,
			"type":     f.Type,
			"isIndex":  f.IsIndex,
			"memo":     f.Memo,
			"settings": f.Settings,
		}
		if f.ID != "" {
			fRecord["id"] = f.ID
		} else {
			// If ID is missing, try to find existing field to update
			existing, _ := fieldTable.List(map[string]any{"name": f.Name})
			if len(existing) > 0 {
				fRecord["id"] = existing[0]["id"]
			}
		}
		fieldRecords = append(fieldRecords, fRecord)
	}

	// 3. Batch Set fields
	return fieldTable.Set(fieldRecords...)
}

// RemoveField deletes one or more fields by name.
func (t *Table) RemoveField(names ...string) error {
	if t.userID == "" {
		return fmt.Errorf("authentication required")
	}

	tableRec := GlobalCache.GetTable(t.Name)
	if tableRec == nil {
		return fmt.Errorf("table %s not found", t.Name)
	}

	fieldTable := t.app.Table(t.Name + ":Field")
	for _, name := range names {
		existing, _ := fieldTable.List(map[string]any{"name": name})
		if len(existing) > 0 {
			err := fieldTable.Remove(cast.String(existing[0]["id"]))
			if err != nil {
				return err
			}
		}
	}
	return nil
}

// Get retrieves a single record.
func (t *Table) Get(id string) (map[string]any, error) {
	if t.userID == "" {
		return nil, fmt.Errorf("authentication required")
	}

	if err := t.checkAuth(id, "read"); err != nil {
		return nil, err
	}

	query := fmt.Sprintf("SELECT * FROM `%s` WHERE id = ? LIMIT 1", t.Name)
	res := t.db.Query(query, id)
	if res.Error != nil {
		return nil, res.Error
	}

	record := res.MapOnR1()
	if len(record) == 0 {
		return nil, nil
	}
	return record, nil
}

// Remove deletes one or more records by ID.
func (t *Table) Remove(ids ...string) error {
	if t.userID == "" {
		return fmt.Errorf("authentication required")
	}

	var removedIDs []string

	// Pre-fetch schema context for business tables
	var tableSchema *TableSchema
	var fields []FieldSchema
	tableRec := GlobalCache.GetTable(t.Name)
	if tableRec != nil {
		cast.Convert(&tableSchema, tableRec)
		fields = GlobalCache.GetFields(tableSchema.ID)
	}

	for _, id := range ids {
		if err := t.checkAuth(id, "write"); err != nil {
			return err
		}

		var record map[string]any
		if t.Name == "_Table" || t.Name == "_Field" || t.Name == "_Policy" {
			res := t.db.Query(fmt.Sprintf("SELECT * FROM `%s` WHERE id = ?", t.Name), id)
			record = res.MapOnR1()
		}

		res := t.db.Delete(t.Name, "id = ?", id)
		if res.Error == nil {
			if t.Name == "_Table" || t.Name == "_Field" || t.Name == "_Policy" {
				if t.Name != "_Policy" {
					_ = t.reconstructAndSyncSchema()
				}
				_ = GlobalCache.Load(t.app)

				if t.Name == "_Table" && record != nil && t.app.hooks.OnRemovedTable != nil {
					var ts TableSchema
					cast.Convert(&ts, record)
					t.app.hooks.OnRemovedTable(&ts)
				} else if t.Name == "_Field" && record != nil && t.app.hooks.OnRemovedField != nil {
					var fts *TableSchema
					GlobalCache.lock.RLock()
					tableName := GlobalCache.TableIDMap[cast.String(record["tableId"])]
					fTableRec := GlobalCache.Tables[tableName]
					GlobalCache.lock.RUnlock()
					if fTableRec != nil {
						cast.Convert(&fts, fTableRec)
					}
					t.app.hooks.OnRemovedField(fts, cast.String(record["name"]))
				}
			} else {
				removedIDs = append(removedIDs, id)
			}
		} else {
			return res.Error
		}
	}

	if len(removedIDs) > 0 && t.app.hooks.OnRemovedRows != nil {
		t.app.hooks.OnRemovedRows(removedIDs, tableSchema, fields)
	}

	return nil
}

// List retrieves multiple records.
func (t *Table) List(where any, args ...any) ([]map[string]any, error) {
	req := QueryRequest{}
	if where != nil {
		switch v := where.(type) {
		case string:
			req.Where = v
			req.Args = args
		case map[string]any:
			req.Where, req.Args = buildWhere(v)
		}
	}

	return t.Query(req)
}

// Query performs a structured query on the current table.
func (t *Table) Query(req QueryRequest) ([]map[string]any, error) {
	if t.userID == "" {
		return nil, fmt.Errorf("authentication required")
	}

	// Apply constraint to where clause
	if t.constraint != nil {
		if req.Where != "" {
			// If it's a string, this is complex to merge safely without parsing SQL.
			// Let's rely on appendAuthAndConstraint passing the constraint.
		}
	}

	sql, args, err := t.app.buildQuery(t, req)
	if err != nil {
		return nil, err
	}
	res := t.db.Query(sql, args...)
	if res.Error != nil {
		return nil, res.Error
	}
	return res.MapResults(), nil
}

// Count returns the number of records.
func (t *Table) Count(where any, args ...any) (int64, error) {
	if t.userID == "" {
		return 0, fmt.Errorf("authentication required")
	}

	query := fmt.Sprintf("SELECT COUNT(*) FROM `%s` ", t.Name)
	whereStr := ""
	if where != nil {
		switch v := where.(type) {
		case string:
			whereStr = v
		case map[string]any:
			w, a := buildWhere(v)
			whereStr = w
			args = a
		}
	}

	var err error
	whereStr, args, err = t.appendAuthAndConstraint(whereStr, args)
	if err != nil {
		return 0, err
	}

	if whereStr != "" {
		query += " WHERE " + whereStr
	}

	res := t.db.Query(query, args...)
	if res.Error != nil {
		return 0, res.Error
	}
	return res.IntOnR1C1(), nil
}

// CountBy returns counts grouped by a field.
func (t *Table) CountBy(field string) (map[any]int64, error) {
	if t.userID == "" {
		return nil, fmt.Errorf("authentication required")
	}

	query := fmt.Sprintf("SELECT `%s`, COUNT(*) as cnt FROM `%s` ", field, t.Name)

	whereStr, args, err := t.appendAuthAndConstraint("", nil)
	if err != nil {
		return nil, err
	}

	if whereStr != "" {
		query += " WHERE " + whereStr
	}

	query += fmt.Sprintf(" GROUP BY `%s` ", field)

	res := t.db.Query(query, args...)
	if res.Error != nil {
		return nil, res.Error
	}
	rows := res.MapResults()
	result := make(map[any]int64)
	for _, row := range rows {
		result[row[field]] = cast.Int64(row["cnt"])
	}
	return result, nil
}

// Fields returns field metadata.
func (t *Table) Fields() ([]FieldSchema, error) {
	if t.userID == "" {
		return nil, fmt.Errorf("authentication required")
	}

	tid := ""
	tableRecord := GlobalCache.GetTable(t.Name)
	if tableRecord != nil {
		tid = cast.String(tableRecord["id"])
	} else {
		return nil, fmt.Errorf("table metadata not found in cache: %s", t.Name)
	}

	return GlobalCache.GetFields(tid), nil
}