gosora/query_gen/pgsql.go

/* WIP Under Really Heavy Construction */
package qgen

import (
	"database/sql"
	"errors"
	"strconv"
	"strings"
)

func init() {
    Registry = append(Registry,
        &PgsqlAdapter{Name: "pgsql", Buffer: make(map[string]DBStmt)},
    )
}

type PgsqlAdapter struct {
    Name        string // ? - Do we really need this? Can't we hard-code this?
    Buffer      map[string]DBStmt
    BufferOrder []string // Map iteration order is random, so we need this to track the order, so we don't get huge diffs every commit
}

// GetName gives you the name of the database adapter. In this case, it's pgsql
func (a *PgsqlAdapter) GetName() string {
    return a.Name
}

func (a *PgsqlAdapter) GetStmt(name string) DBStmt {
    return a.Buffer[name]
}

func (a *PgsqlAdapter) GetStmts() map[string]DBStmt {
    return a.Buffer
}

// TODO: Implement this
func (a *PgsqlAdapter) BuildConn(config map[string]string) (*sql.DB, error) {
    return nil, nil
}

func (a *PgsqlAdapter) DbVersion() string {
    return "SELECT version()"
}

func (a *PgsqlAdapter) DropTable(name, table string) (string, error) {
    if table == "" {
        return "", errors.New("You need a name for this table")
    }
    q := "DROP TABLE IF EXISTS \"" + table + "\";"
    a.pushStatement(name, "drop-table", q)
    return q, nil
}

// TODO: Implement this
// We may need to change the CreateTable API to better suit PGSQL and the other database drivers which are coming up
func (a *PgsqlAdapter) CreateTable(name, table, charset, collation string, cols []DBTableColumn, keys []DBTableKey) (string, error) {
    if table == "" {
        return "", errors.New("You need a name for this table")
    }
    if len(cols) == 0 {
        return "", errors.New("You can't have a table with no columns")
    }

    q := "CREATE TABLE \"" + table + "\" ("
    for _, col := range cols {
        if col.AutoIncrement {
            col.Type = "serial"
        } else if col.Type == "createdAt" {
            col.Type = "timestamp"
        } else if col.Type == "datetime" {
            col.Type = "timestamp"
        }

        var size string
        if col.Size > 0 {
            size = " (" + strconv.Itoa(col.Size) + ")"
        }

        var end string
        if col.Default != "" {
            end = " DEFAULT "
            if a.stringyType(col.Type) && col.Default != "''" {
                end += "'" + col.Default + "'"
            } else {
                end += col.Default
            }
        }
        if !col.Null {
            end += " not null"
        }

        q += "\n\t`" + col.Name + "` " + col.Type + size + end + ","
    }

    if len(keys) > 0 {
        for _, key := range keys {
            q += "\n\t" + key.Type
            if key.Type != "unique" {
                q += " key"
            }
            q += "("
            for _, column := range strings.Split(key.Columns, ",") {
                q += "`" + column + "`,"
            }
            q = q[0:len(q)-1] + "),"
        }
    }

    q = q[0:len(q)-1] + "\n);"
    a.pushStatement(name, "create-table", q)
    return q, nil
}

// TODO: Implement this
func (a *PgsqlAdapter) AddColumn(name, table string, column DBTableColumn, key *DBTableKey) (string, error) {
    if table == "" {
        return "", errors.New("You need a name for this table")
    }
    return "", nil
}

// TODO: Implement this
func (a *PgsqlAdapter) DropColumn(name, table, colName string) (string, error) {
    return "", errors.New("not implemented")
}

// TODO: Implement this
func (a *PgsqlAdapter) RenameColumn(name, table, oldName, newName string) (string, error) {
    return "", errors.New("not implemented")
}

// TODO: Implement this
func (a *PgsqlAdapter) ChangeColumn(name, table, colName string, col DBTableColumn) (string, error) {
    return "", errors.New("not implemented")
}

// TODO: Implement this
func (a *PgsqlAdapter) SetDefaultColumn(name, table, colName, colType, defaultStr string) (string, error) {
    if colType == "text" {
        return "", errors.New("text fields cannot have default values")
    }
    return "", errors.New("not implemented")
}

// TODO: Implement this
// TODO: Test to make sure everything works here
func (a *PgsqlAdapter) AddIndex(name, table, iname, colname string) (string, error) {
    if table == "" {
        return "", errors.New("You need a name for this table")
    }
    if iname == "" {
        return "", errors.New("You need a name for the index")
    }
    if colname == "" {
        return "", errors.New("You need a name for the column")
    }
    return "", errors.New("not implemented")
}

// TODO: Implement this
// TODO: Test to make sure everything works here
func (a *PgsqlAdapter) AddKey(name, table, column string, key DBTableKey) (string, error) {
    if table == "" {
        return "", errors.New("You need a name for this table")
    }
    if column == "" {
        return "", errors.New("You need a name for the column")
    }
    return "", errors.New("not implemented")
}

// TODO: Implement this
// TODO: Test to make sure everything works here
func (a *PgsqlAdapter) RemoveIndex(name, table, iname string) (string, error) {
    if table == "" {
        return "", errors.New("You need a name for this table")
    }
    if iname == "" {
        return "", errors.New("You need a name for the index")
    }
    return "", errors.New("not implemented")
}

// TODO: Implement this
// TODO: Test to make sure everything works here
func (a *PgsqlAdapter) AddForeignKey(name, table, column, ftable, fcolumn string, cascade bool) (out string, e error) {
    var c = func(str string, val bool) {
        if e != nil || !val {
            return
        }
        e = errors.New("You need a " + str + " for this table")
    }
    c("name", table == "")
    c("column", column == "")
    c("ftable", ftable == "")
    c("fcolumn", fcolumn == "")
    if e != nil {
        return "", e
    }
    return "", errors.New("not implemented")
}

// TODO: Test this
// ! We need to get the last ID out of this somehow, maybe add returning to every query? Might require some sort of wrapper over the sql statements
func (a *PgsqlAdapter) SimpleInsert(name, table, columns, fields string) (string, error) {
    if table == "" {
        return "", errors.New("You need a name for this table")
    }

    q := "INSERT INTO \"" + table + "\"("
    if columns != "" {
        q += a.buildColumns(columns) + ") VALUES ("
        for _, field := range processFields(fields) {
            nameLen := len(field.Name)
            if field.Name[0] == '"' && field.Name[nameLen-1] == '"' && nameLen >= 3 {
                field.Name = "'" + field.Name[1:nameLen-1] + "'"
            }
            if field.Name[0] == '\'' && field.Name[nameLen-1] == '\'' && nameLen >= 3 {
                field.Name = "'" + strings.Replace(field.Name[1:nameLen-1], "'", "''", -1) + "'"
            }
            q += field.Name + ","
        }
        q = q[0 : len(q)-1]
    } else {
        q += ") VALUES ("
    }
    q += ")"

    a.pushStatement(name, "insert", q)
    return q, nil
}

// TODO: Implement this
func (a *PgsqlAdapter) SimpleBulkInsert(name, table, columns string, fieldSet []string) (string, error) {
    return "", nil
}

func (a *PgsqlAdapter) buildColumns(cols string) (q string) {
    if cols == "" {
        return ""
    }
    // Escape the column names, just in case we've used a reserved keyword
    for _, col := range processColumns(cols) {
        if col.Type == TokenFunc {
            q += col.Left + ","
        } else {
            q += "\"" + col.Left + "\","
        }
    }
    return q[0 : len(q)-1]
}

// TODO: Implement this
func (a *PgsqlAdapter) SimpleReplace(name, table, columns, fields string) (string, error) {
    if table == "" {
        return "", errors.New("You need a name for this table")
    }
    if len(columns) == 0 {
        return "", errors.New("No columns found for SimpleInsert")
    }
    if len(fields) == 0 {
        return "", errors.New("No input data found for SimpleInsert")
    }
    return "", nil
}

// TODO: Implement this
func (a *PgsqlAdapter) SimpleUpsert(name, table, columns, fields, where string) (string, error) {
    if table == "" {
        return "", errors.New("You need a name for this table")
    }
    if len(columns) == 0 {
        return "", errors.New("No columns found for SimpleInsert")
    }
    if len(fields) == 0 {
        return "", errors.New("No input data found for SimpleInsert")
    }
    return "", nil
}

// TODO: Implemented, but we need CreateTable and a better installer to *test* it
func (a *PgsqlAdapter) SimpleUpdate(up *updatePrebuilder) (string, error) {
    if up.table == "" {
        return "", errors.New("You need a name for this table")
    }
    if up.set == "" {
        return "", errors.New("You need to set data in this update statement")
    }

    q := "UPDATE \"" + up.table + "\" SET "
    for _, item := range processSet(up.set) {
        q += "`" + item.Column + "`="
        for _, token := range item.Expr {
            switch token.Type {
            case TokenFunc:
                // TODO: Write a more sophisticated function parser on the utils side.
                if strings.ToUpper(token.Contents) == "UTC_TIMESTAMP()" {
                    token.Contents = "LOCALTIMESTAMP()"
                }
                q += " " + token.Contents
            case TokenOp, TokenNumber, TokenSub, TokenOr:
                q += " " + token.Contents
            case TokenColumn:
                q += " `" + token.Contents + "`"
            case TokenString:
                q += " '" + token.Contents + "'"
            }
        }
        q += ","
    }
    q = q[0 : len(q)-1]

    // Add support for BETWEEN x.x
    if len(up.where) != 0 {
        q += " WHERE"
        for _, loc := range processWhere(up.where) {
            for _, token := range loc.Expr {
                switch token.Type {
                case TokenFunc:
                    // TODO: Write a more sophisticated function parser on the utils side. What's the situation in regards to case sensitivity?
                    if strings.ToUpper(token.Contents) == "UTC_TIMESTAMP()" {
                        token.Contents = "LOCALTIMESTAMP()"
                    }
                    q += " " + token.Contents
                case TokenOp, TokenNumber, TokenSub, TokenOr, TokenNot, TokenLike:
                    q += " " + token.Contents
                case TokenColumn:
                    q += " `" + token.Contents + "`"
                case TokenString:
                    q += " '" + token.Contents + "'"
                default:
                    panic("This token doesn't exist o_o")
                }
            }
            q += " AND"
        }
        q = q[0 : len(q)-4]
    }

    a.pushStatement(up.name, "update", q)
    return q, nil
}

// TODO: Implement this
func (a *PgsqlAdapter) SimpleUpdateSelect(up *updatePrebuilder) (string, error) {
    return "", errors.New("not implemented")
}

// TODO: Implement this
func (a *PgsqlAdapter) SimpleDelete(name, table, where string) (string, error) {
    if table == "" {
        return "", errors.New("You need a name for this table")
    }
    if where == "" {
        return "", errors.New("You need to specify what data you want to delete")
    }
    return "", nil
}

// TODO: Implement this
func (a *PgsqlAdapter) ComplexDelete(b *deletePrebuilder) (string, error) {
    if b.table == "" {
        return "", errors.New("You need a name for this table")
    }
    if b.where == "" {
        return "", errors.New("You need to specify what data you want to delete")
    }
    return "", nil
}

// TODO: Implement this
// We don't want to accidentally wipe tables, so we'll have a separate method for purging tables instead
func (a *PgsqlAdapter) Purge(name, table string) (string, error) {
    if table == "" {
        return "", errors.New("You need a name for this table")
    }
    return "", nil
}

// TODO: Implement this
func (a *PgsqlAdapter) SimpleSelect(name, table, columns, where, orderby, limit string) (string, error) {
    if table == "" {
        return "", errors.New("You need a name for this table")
    }
    if len(columns) == 0 {
        return "", errors.New("No columns found for SimpleSelect")
    }
    return "", nil
}

// TODO: Implement this
func (a *PgsqlAdapter) ComplexSelect(prebuilder *selectPrebuilder) (string, error) {
    if prebuilder.table == "" {
        return "", errors.New("You need a name for this table")
    }
    if len(prebuilder.columns) == 0 {
        return "", errors.New("No columns found for ComplexSelect")
    }
    return "", nil
}

// TODO: Implement this
func (a *PgsqlAdapter) SimpleLeftJoin(name, table1, table2, columns, joiners, where, orderby, limit string) (string, error) {
    if table1 == "" {
        return "", errors.New("You need a name for the left table")
    }
    if table2 == "" {
        return "", errors.New("You need a name for the right table")
    }
    if len(columns) == 0 {
        return "", errors.New("No columns found for SimpleLeftJoin")
    }
    if len(joiners) == 0 {
        return "", errors.New("No joiners found for SimpleLeftJoin")
    }
    return "", nil
}

// TODO: Implement this
func (a *PgsqlAdapter) SimpleInnerJoin(name, table1, table2, columns, joiners, where, orderby, limit string) (string, error) {
    if table1 == "" {
        return "", errors.New("You need a name for the left table")
    }
    if table2 == "" {
        return "", errors.New("You need a name for the right table")
    }
    if len(columns) == 0 {
        return "", errors.New("No columns found for SimpleInnerJoin")
    }
    if len(joiners) == 0 {
        return "", errors.New("No joiners found for SimpleInnerJoin")
    }
    return "", nil
}

// TODO: Implement this
func (a *PgsqlAdapter) SimpleInsertSelect(name string, ins DBInsert, sel DBSelect) (string, error) {
    return "", nil
}

// TODO: Implement this
func (a *PgsqlAdapter) SimpleInsertLeftJoin(name string, ins DBInsert, sel DBJoin) (string, error) {
    return "", nil
}

// TODO: Implement this
func (a *PgsqlAdapter) SimpleInsertInnerJoin(name string, ins DBInsert, sel DBJoin) (string, error) {
    return "", nil
}

// TODO: Implement this
func (a *PgsqlAdapter) SimpleCount(name, table, where, limit string) (string, error) {
    if table == "" {
        return "", errors.New("You need a name for this table")
    }
    return "", nil
}

func (a *PgsqlAdapter) Builder() *prebuilder {
    return &prebuilder{a}
}

func (a *PgsqlAdapter) Write() error {
    var stmts, body string
    for _, name := range a.BufferOrder {
        if name[0] == '_' {
            continue
        }
        stmt := a.Buffer[name]
        // TODO: Add support for create-table? Table creation might be a little complex for Go to do outside a SQL file :(
        if stmt.Type != "create-table" {
            stmts += "\t" + name + " *sql.Stmt\n"
            body += `    
    common.DebugLog("Preparing ` + name + ` statement.")
    stmts.` + name + `, err = db.Prepare("` + strings.Replace(stmt.Contents, "\"", "\\\"", -1) + `")
    if err != nil {
        log.Print("Error in ` + name + ` statement.")
        return err
    }
    `
        }
    }

    // TODO: Move these custom queries out of this file
    out := `// +build pgsql

// This file was generated by Gosora's Query Generator. Please try to avoid modifying this file, as it might change at any time.
package main

import "log"
import "database/sql"
import "git.tuxpa.in/a/gosora/common"

// nolint
type Stmts struct {
` + stmts + `
    getActivityFeedByWatcher *sql.Stmt
    getActivityCountByWatcher *sql.Stmt

    Mocks bool
}

// nolint
func _gen_pgsql() (err error) {
    common.DebugLog("Building the generated statements")
` + body + `
    return nil
}
`
    return writeFile("./gen_pgsql.go", out)
}

// Internal methods, not exposed in the interface
func (a *PgsqlAdapter) pushStatement(name, stype, q string) {
    if name == "" {
        return
    }
    a.Buffer[name] = DBStmt{q, stype}
    a.BufferOrder = append(a.BufferOrder, name)
}

func (a *PgsqlAdapter) stringyType(ctype string) bool {
    ctype = strings.ToLower(ctype)
    return ctype == "char" || ctype == "varchar" || ctype == "timestamp" || ctype == "text"
}