feat: update evaluation schema and refactor skill evaluations

- Added unique constraint on users table for first_name, last_name, and team_id.
- Removed category_evaluations and selected_skills tables, simplifying the schema.
- Updated skill_evaluations to directly reference user_evaluations and include is_selected flag.
- Refactored EvaluationService to handle skill evaluations directly, improving data integrity and performance.
- Introduced new queries for loading skills and evaluations, enhancing data retrieval efficiency.
- Added views for user skills summary and category skills count for easier querying.

scripts/init.sql

@@ -45,10 +45,15 @@ CREATE TABLE users (
     last_name VARCHAR(100) NOT NULL,
     team_id VARCHAR(50) REFERENCES teams(id),
     created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
-    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    UNIQUE(first_name, last_name, team_id)
 );
 
--- User evaluations table
+-- ========================================
+-- SIMPLIFIED EVALUATION SCHEMA
+-- ========================================
+
+-- User evaluations - metadata about user's evaluation session
 CREATE TABLE user_evaluations (
     id SERIAL PRIMARY KEY,
     user_id INTEGER REFERENCES users(id) ON DELETE CASCADE,
@@ -57,35 +62,18 @@ CREATE TABLE user_evaluations (
     UNIQUE(user_id)
 );
 
--- Category evaluations table
-CREATE TABLE category_evaluations (
-    id SERIAL PRIMARY KEY,
-    user_evaluation_id INTEGER REFERENCES user_evaluations(id) ON DELETE CASCADE,
-    category VARCHAR(100) NOT NULL,
-    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
-    UNIQUE(user_evaluation_id, category)
-);
-
--- Selected skills table (skills the user wants to evaluate)
-CREATE TABLE selected_skills (
-    id SERIAL PRIMARY KEY,
-    category_evaluation_id INTEGER REFERENCES category_evaluations(id) ON DELETE CASCADE,
-    skill_id VARCHAR(100) NOT NULL,
-    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
-    UNIQUE(category_evaluation_id, skill_id)
-);
-
--- Skill evaluations table
+-- Skill evaluations - direct relationship between user and skill
 CREATE TABLE skill_evaluations (
     id SERIAL PRIMARY KEY,
-    category_evaluation_id INTEGER REFERENCES category_evaluations(id) ON DELETE CASCADE,
-    skill_id VARCHAR(100) NOT NULL,
+    user_evaluation_id INTEGER REFERENCES user_evaluations(id) ON DELETE CASCADE,
+    skill_id VARCHAR(100) REFERENCES skills(id) ON DELETE CASCADE,
     level skill_level_enum NOT NULL,
     can_mentor BOOLEAN DEFAULT FALSE,
     wants_to_learn BOOLEAN DEFAULT FALSE,
+    is_selected BOOLEAN DEFAULT TRUE, -- Replaces selected_skills table
     created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
     updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
-    UNIQUE(category_evaluation_id, skill_id)
+    UNIQUE(user_evaluation_id, skill_id)
 );
 
 -- Insert initial teams data
@@ -104,11 +92,11 @@ CREATE INDEX idx_teams_direction ON teams(direction);
 CREATE INDEX idx_skills_category_id ON skills(category_id);
 CREATE INDEX idx_skill_links_skill_id ON skill_links(skill_id);
 CREATE INDEX idx_users_team_id ON users(team_id);
+CREATE INDEX idx_users_unique_person ON users(first_name, last_name, team_id);
 CREATE INDEX idx_user_evaluations_user_id ON user_evaluations(user_id);
-CREATE INDEX idx_category_evaluations_user_evaluation_id ON category_evaluations(user_evaluation_id);
-CREATE INDEX idx_selected_skills_category_evaluation_id ON selected_skills(category_evaluation_id);
-CREATE INDEX idx_skill_evaluations_category_evaluation_id ON skill_evaluations(category_evaluation_id);
+CREATE INDEX idx_skill_evaluations_user_evaluation_id ON skill_evaluations(user_evaluation_id);
 CREATE INDEX idx_skill_evaluations_skill_id ON skill_evaluations(skill_id);
+CREATE INDEX idx_skill_evaluations_is_selected ON skill_evaluations(is_selected);
 
 -- Update trigger for users table
 CREATE OR REPLACE FUNCTION update_updated_at_column()
@@ -133,3 +121,33 @@ CREATE TRIGGER update_users_updated_at BEFORE UPDATE ON users
 
 CREATE TRIGGER update_skill_evaluations_updated_at BEFORE UPDATE ON skill_evaluations
     FOR EACH ROW EXECUTE FUNCTION update_updated_at_column();
+
+-- Views for easy querying
+CREATE VIEW user_skills_summary AS
+SELECT 
+    u.first_name,
+    u.last_name,
+    t.name as team_name,
+    t.direction,
+    sc.name as category_name,
+    s.name as skill_name,
+    se.level,
+    se.can_mentor,
+    se.wants_to_learn,
+    se.is_selected,
+    se.updated_at
+FROM users u
+JOIN teams t ON u.team_id = t.id
+JOIN user_evaluations ue ON u.id = ue.user_id
+JOIN skill_evaluations se ON ue.id = se.user_evaluation_id
+JOIN skills s ON se.skill_id = s.id
+JOIN skill_categories sc ON s.category_id = sc.id;
+
+CREATE VIEW category_skills_count AS
+SELECT 
+    sc.id as category_id,
+    sc.name as category_name,
+    COUNT(s.id) as total_skills
+FROM skill_categories sc
+LEFT JOIN skills s ON sc.id = s.category_id
+GROUP BY sc.id, sc.name;