From 49de041998ae8946c399126de2fedbb7e5bd916b Mon Sep 17 00:00:00 2001
From: Daisuke Maki <lestrrat+github@gmail.com>
Date: Fri, 17 Feb 2017 07:20:50 +0900
Subject: [PATCH] Change how to identify an index

---
 format/format_test.go |  2 +-
 model/index.go        | 20 +++++++++++++++-----
 model/interface.go    |  1 +
 parser.go             | 18 +++++++++---------
 4 files changed, 26 insertions(+), 15 deletions(-)

diff --git a/format/format_test.go b/format/format_test.go
index 5a57a39..5f5d4f9 100644
--- a/format/format_test.go
+++ b/format/format_test.go
@@ -22,7 +22,7 @@ func TestFormat(t *testing.T) {
 	opt := model.NewTableOption("ENGINE", "InnoDB", false)
 	table.AddOption(opt)
 
-	index := model.NewIndex(model.IndexKindPrimaryKey)
+	index := model.NewIndex(model.IndexKindPrimaryKey, table.ID())
 	index.SetName("hoge_pk")
 	index.AddColumns("fuga")
 	table.AddIndex(index)
diff --git a/model/index.go b/model/index.go
index f463e3e..3ac8dce 100644
--- a/model/index.go
+++ b/model/index.go
@@ -3,26 +3,36 @@ package model
 import (
 	"crypto/sha256"
 	"fmt"
-	"io"
 )
 
 // NewIndex creates a new index with the given index kind.
-func NewIndex(kind IndexKind) Index {
+func NewIndex(kind IndexKind, table string) Index {
 	return &index{
-		kind: kind,
+		kind:  kind,
+		table: table,
 	}
 }
 
 func (stmt *index) ID() string {
 	// This is tricky. and index may or may not have a name. It would
 	// have been so much easier if we did, but we don't, so we'll fake
-	// something
+	// something.
+	//
+	// In case we don't have a name, we need to know the table, the kind,
+	// the type, // the column(s), and the reference(s).
 	name := "index"
 	if stmt.HasName() {
 		name = name + "#" + stmt.Name()
 	}
 	h := sha256.New()
-	io.WriteString(h, fmt.Sprintf("%v, %v, %v, %v, %v, %v", stmt.symbol, stmt.kind, stmt.name, stmt.typ, stmt.columns, stmt.reference))
+	fmt.Fprintf(h,
+		"%s.%s.%s.%v.%s",
+		stmt.table,
+		stmt.kind,
+		stmt.typ,
+		stmt.columns,
+		stmt.reference,
+	)
 	return fmt.Sprintf("%s#%x", name, h.Sum(nil))
 }
 
diff --git a/model/interface.go b/model/interface.go
index 613b2b4..12531c8 100644
--- a/model/interface.go
+++ b/model/interface.go
@@ -73,6 +73,7 @@ type index struct {
 	kind    IndexKind
 	name    maybeString
 	typ     IndexType
+	table   string
 	columns []string
 	// TODO Options.
 	reference Reference
diff --git a/parser.go b/parser.go
index 12e36f4..e650687 100644
--- a/parser.go
+++ b/parser.go
@@ -360,17 +360,17 @@ func (p *Parser) parseTableConstraint(ctx *parseCtx, table model.Table) error {
 	var index model.Index
 	switch t := ctx.peek(); t.Type {
 	case PRIMARY:
-		index = model.NewIndex(model.IndexKindPrimaryKey)
+		index = model.NewIndex(model.IndexKindPrimaryKey, table.ID())
 		if err := p.parseColumnIndexPrimaryKey(ctx, index); err != nil {
 			return err
 		}
 	case UNIQUE:
-		index = model.NewIndex(model.IndexKindUnique)
+		index = model.NewIndex(model.IndexKindUnique, table.ID())
 		if err := p.parseColumnIndexUniqueKey(ctx, index); err != nil {
 			return err
 		}
 	case FOREIGN:
-		index = model.NewIndex(model.IndexKindForeignKey)
+		index = model.NewIndex(model.IndexKindForeignKey, table.ID())
 		if err := p.parseColumnIndexForeignKey(ctx, index); err != nil {
 			return err
 		}
@@ -387,7 +387,7 @@ func (p *Parser) parseTableConstraint(ctx *parseCtx, table model.Table) error {
 }
 
 func (p *Parser) parseTablePrimaryKey(ctx *parseCtx, table model.Table) error {
-	index := model.NewIndex(model.IndexKindPrimaryKey)
+	index := model.NewIndex(model.IndexKindPrimaryKey, table.ID())
 	if err := p.parseColumnIndexPrimaryKey(ctx, index); err != nil {
 		return err
 	}
@@ -396,7 +396,7 @@ func (p *Parser) parseTablePrimaryKey(ctx *parseCtx, table model.Table) error {
 }
 
 func (p *Parser) parseTableUniqueKey(ctx *parseCtx, table model.Table) error {
-	index := model.NewIndex(model.IndexKindUnique)
+	index := model.NewIndex(model.IndexKindUnique, table.ID())
 	if err := p.parseColumnIndexUniqueKey(ctx, index); err != nil {
 		return err
 	}
@@ -405,7 +405,7 @@ func (p *Parser) parseTableUniqueKey(ctx *parseCtx, table model.Table) error {
 }
 
 func (p *Parser) parseTableIndex(ctx *parseCtx, table model.Table) error {
-	index := model.NewIndex(model.IndexKindNormal)
+	index := model.NewIndex(model.IndexKindNormal, table.ID())
 	if err := p.parseColumnIndexKey(ctx, index); err != nil {
 		return err
 	}
@@ -414,7 +414,7 @@ func (p *Parser) parseTableIndex(ctx *parseCtx, table model.Table) error {
 }
 
 func (p *Parser) parseTableFulltextIndex(ctx *parseCtx, table model.Table) error {
-	index := model.NewIndex(model.IndexKindFullText)
+	index := model.NewIndex(model.IndexKindFullText, table.ID())
 	if err := p.parseColumnIndexFullTextKey(ctx, index); err != nil {
 		return err
 	}
@@ -423,7 +423,7 @@ func (p *Parser) parseTableFulltextIndex(ctx *parseCtx, table model.Table) error
 }
 
 func (p *Parser) parseTableSpatialIndex(ctx *parseCtx, table model.Table) error {
-	index := model.NewIndex(model.IndexKindSpatial)
+	index := model.NewIndex(model.IndexKindSpatial, table.ID())
 	if err := p.parseColumnIndexSpatialKey(ctx, index); err != nil {
 		return err
 	}
@@ -432,7 +432,7 @@ func (p *Parser) parseTableSpatialIndex(ctx *parseCtx, table model.Table) error
 }
 
 func (p *Parser) parseTableForeignKey(ctx *parseCtx, table model.Table) error {
-	index := model.NewIndex(model.IndexKindForeignKey)
+	index := model.NewIndex(model.IndexKindForeignKey, table.ID())
 	if err := p.parseColumnIndexForeignKey(ctx, index); err != nil {
 		return err
 	}