added ServerConfigurationMapping

split up Abstractions so we have one type per file.

pgLabII.PgUtils/ConnectionStrings/PLAN.md

@@ -0,0 +1,51 @@
+# Connection Strings Plan
+
+This document tracks the plan for supporting multiple PostgreSQL connection string formats, converting between them, and mapping to/from a canonical model.
+
+## Current Status (2025-08-30)
+
+Implemented:
+- Abstractions: `ConnStringFormat`, `HostEndpoint`, `ConnectionDescriptor`, `IConnectionStringCodec`, `IConnectionStringService`.
+- Codecs:
+  - `LibpqCodec` (libpq): parse/format; multi-host; `sslmode`, `application_name`, `connect_timeout`; quoting/escaping; preserves extras.
+  - `NpgsqlCodec` (.NET/Npgsql): parse/format; alias recognition; multi-host with single or per-host ports; `SSL Mode`, `Application Name`, `Timeout`; double-quote rules; preserves extras.
+- Tests for both codecs: parse, format, round-trip, edge quoting.
+
+Not yet implemented:
+- URL (postgresql://) codec ✓
+- JDBC (jdbc:postgresql://) codec
+- Composite `ConnectionStringService` (detect + convert) ✓
+- Mapping helpers to/from `ServerConfiguration` ✓
+
+## Updated Plan
+
+1. Define canonical model and interfaces for connection strings. ✓
+2. Establish normalization strategy for parameter aliases and extra `Properties` handling. ✓
+3. Implement format-specific codecs:
+   - libpq codec (parse/format; multi-host, quoting, sslmode, timeout, extras). ✓
+   - Npgsql codec (parse/format; aliases, multi-host/ports, quoting, ssl mode, timeout, extras). ✓
+   - URL (postgresql://) codec (parse/format; userinfo, host[:port], db, query params, percent-encoding). ✓
+   - JDBC (jdbc:postgresql://) codec (parse/format; hosts, ports, db, properties; URL-like semantics).
+4. Composite conversion service:
+   - Implement `ConnectionStringService` composing codecs, detecting formats, converting via `ConnectionDescriptor`, and resolving alias priorities.
+5. Mapping with application model:
+   - Add mapping utilities between `ConnectionDescriptor` and `ServerConfiguration` (primary host/port, db, SSL mode), with sensible defaults.
+6. Validation and UX:
+   - Validation for malformed inputs & edge cases (mismatched host/port counts, invalid SSL mode, missing db/host, IPv6 bracket handling).
+   - Ensure sensitive fields (password) are masked in logs/preview.
+7. Tests:
+   - Unit tests for URL and JDBC codecs; composite service detect/convert; mapping functions; cross-format round-trips; edge cases (spaces, quotes, unicode, IPv6, percent-encoding).
+8. Documentation:
+   - Keep this plan updated and enrich XML docs on codecs/service including alias mappings and quoting/escaping rules per format.
+
+## Next Small Step
+
+Implement the URL (postgresql://) codec with unit tests. Scope:
+- Parse: `postgresql://[user[:password]@]host1[:port1][,hostN[:portN]]/[database]?param=value&...`
+  - Support percent-decoding for user, password, database, and query values.
+  - Handle IPv6 literals in `[::1]` form; allow multiple hosts with optional per-host ports.
+  - Map common params: `sslmode`, `application_name`, `connect_timeout` and preserve other query params in `Properties`.
+- Format: Build a URL using percent-encoding where required; emit multi-hosts and parameters from `Properties` not already emitted.
+- Tests: basic parse/format, quoting/percent-encoding, multi-host with mixed ports, round-trips.
+
+After that, implement the composite `ConnectionStringService` to detect/convert across libpq, Npgsql, and URL formats.