# DCTX Writer

Generates Clarion database dictionary (DCTX) files from database schema information.

## Overview

The DCTX Writer converts RelSpec's internal database model representation into Clarion dictionary XML format, used by the Clarion development platform.

## Features

- Generates DCTX XML format
- Creates file (table) definitions
- Defines fields (columns) with Clarion types
- Includes keys (indexes)
- Handles relationships

## Usage

### Basic Example

```go
package main

import (
    "git.warky.dev/wdevs/relspecgo/pkg/models"
    "git.warky.dev/wdevs/relspecgo/pkg/writers"
    "git.warky.dev/wdevs/relspecgo/pkg/writers/dctx"
)

func main() {
    options := &writers.WriterOptions{
        OutputPath: "database.dctx",
    }

    writer := dctx.NewWriter(options)
    err := writer.WriteDatabase(db)
    if err != nil {
        panic(err)
    }
}
```

### CLI Examples

```bash
# Generate DCTX from PostgreSQL database (for Clarion migration)
relspec --input pgsql \
  --conn "postgres://localhost/mydb" \
  --output dctx \
  --out-file app.dctx

# Convert GORM models to DCTX
relspec --input gorm --in-file models.go --output dctx --out-file legacy.dctx

# Convert JSON schema to DCTX
relspec --input json --in-file schema.json --output dctx --out-file database.dctx
```

## Type Mapping

Converts standard SQL types to Clarion types:

| SQL Type | Clarion Type | Notes |
|----------|--------------|-------|
| VARCHAR(n) | STRING(n) | Fixed-length string |
| TEXT | STRING | Variable length |
| INTEGER | LONG | 32-bit integer |
| BIGINT | DECIMAL(20,0) | Large integer |
| SMALLINT | SHORT | 16-bit integer |
| NUMERIC(p,s) | DECIMAL(p,s) | Decimal number |
| REAL, FLOAT | REAL | Floating point |
| BOOLEAN | BYTE | 0/1 value |
| DATE | DATE | Date field |
| TIME | TIME | Time field |
| TIMESTAMP | LONG | Unix timestamp |

## DCTX Structure

DCTX files are XML-based with this structure:

```xml
<?xml version="1.0"?>
<dictionary>
  <file name="USERS" driver="TOPSPEED">
    <record>
      <field name="ID" type="LONG" />
      <field name="USERNAME" type="STRING" bytes="50" />
      <field name="EMAIL" type="STRING" bytes="100" />
    </record>
    <key name="KEY_PRIMARY" primary="true">
      <field name="ID" />
    </key>
  </file>
</dictionary>
```

## Features

- File definitions (equivalent to tables)
- Field definitions with Clarion-specific types
- Key definitions (primary and foreign)
- Relationships between files
- Driver specifications (TOPSPEED, SQL, etc.)

## Notes

- DCTX is specific to Clarion development
- Useful for legacy system integration
- Field names are typically uppercase in Clarion
- Supports Clarion-specific attributes
- Can be imported into Clarion IDE