From e063f023fb0f0c126d80593cd8b02cea6c197c43 Mon Sep 17 00:00:00 2001
From: Steven Dracker <steven.dracker@gmail.com>
Date: Sun, 29 Mar 2026 15:11:33 -0400
Subject: [PATCH] feat(CC-ERATE-000056): add Postgres as configurable database
 provider
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Introduces DatabaseProvider config key ("Sqlite" | "Postgres") alongside
Npgsql.EntityFrameworkCore.PostgreSQL 8.0.11. Startup branches on provider:
SQLite continues to use Migrate(); Postgres uses EnsureCreated() to bypass
SQLite-specific PRAGMA migrations. Provider name is logged at startup.
Default remains SQLite — no behaviour change unless DatabaseProvider=Postgres.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 .../ErateWorkbench.Api.csproj                 |  1 +
 src/ErateWorkbench.Api/Program.cs             | 28 +++++++++++++++----
 src/ErateWorkbench.Api/appsettings.json       |  4 ++-
 3 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/src/ErateWorkbench.Api/ErateWorkbench.Api.csproj b/src/ErateWorkbench.Api/ErateWorkbench.Api.csproj
index 2a7e6fc..02ca720 100644
--- a/src/ErateWorkbench.Api/ErateWorkbench.Api.csproj
+++ b/src/ErateWorkbench.Api/ErateWorkbench.Api.csproj
@@ -20,6 +20,7 @@
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
+    <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="8.*" />
     <PackageReference Include="Swashbuckle.AspNetCore" Version="6.6.2" />
   </ItemGroup>
 
diff --git a/src/ErateWorkbench.Api/Program.cs b/src/ErateWorkbench.Api/Program.cs
index a2ec96b..15e7c49 100644
--- a/src/ErateWorkbench.Api/Program.cs
+++ b/src/ErateWorkbench.Api/Program.cs
@@ -29,11 +29,23 @@
         includeControllerXmlComments: true);
 });
 
-var connectionString = builder.Configuration.GetConnectionString("DefaultConnection")
-    ?? "Data Source=erate-workbench.db";
+var dbProvider = builder.Configuration["DatabaseProvider"] ?? "Sqlite";
 
 builder.Services.AddDbContext<AppDbContext>(options =>
-    options.UseSqlite(connectionString));
+{
+    if (dbProvider.Equals("Postgres", StringComparison.OrdinalIgnoreCase))
+    {
+        var pgConn = builder.Configuration.GetConnectionString("Postgres")
+            ?? throw new InvalidOperationException("ConnectionStrings:Postgres is required when DatabaseProvider=Postgres");
+        options.UseNpgsql(pgConn);
+    }
+    else
+    {
+        var sqliteConn = builder.Configuration.GetConnectionString("DefaultConnection")
+            ?? "Data Source=erate-workbench.db";
+        options.UseSqlite(sqliteConn);
+    }
+});
 
 builder.Services.AddHttpClient<UsacCsvClient>();
 builder.Services.AddScoped<ApplicantCsvParser>();
@@ -91,11 +103,17 @@
 
 app.UseHttpsRedirection();
 
-// Apply migrations on startup
+// Apply migrations on startup (SQLite) or create schema (Postgres)
 using (var scope = app.Services.CreateScope())
 {
     var dbContext = scope.ServiceProvider.GetRequiredService<AppDbContext>();
-    dbContext.Database.Migrate();
+    var startupLogger = scope.ServiceProvider.GetRequiredService<ILogger<AppDbContext>>();
+    startupLogger.LogInformation("Database provider: {Provider}", dbProvider);
+
+    if (dbProvider.Equals("Postgres", StringComparison.OrdinalIgnoreCase))
+        dbContext.Database.EnsureCreated();
+    else
+        dbContext.Database.Migrate();
 }
 
 // --- Health ---
diff --git a/src/ErateWorkbench.Api/appsettings.json b/src/ErateWorkbench.Api/appsettings.json
index 1cfdf8e..443a767 100644
--- a/src/ErateWorkbench.Api/appsettings.json
+++ b/src/ErateWorkbench.Api/appsettings.json
@@ -9,7 +9,9 @@
     }
   },
   "AllowedHosts": "*",
+  "DatabaseProvider": "Sqlite",
   "ConnectionStrings": {
-    "DefaultConnection": "Data Source=erate-workbench.db"
+    "DefaultConnection": "Data Source=erate-workbench.db",
+    "Postgres": "Host=localhost;Port=5432;Database=eratedb;Username=erate;Password=erate"
   }
 }