-- Migration 009: Teams and Multi-Tenancy
-- Adds support for team-based multi-tenancy
-- Part of Multi-Tenancy with Teams feature

-- Create teams table
CREATE TABLE IF NOT EXISTS teams (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    name VARCHAR(255) NOT NULL,
    slug VARCHAR(255) NOT NULL UNIQUE,
    description TEXT,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
    created_by VARCHAR(255) NOT NULL,
    settings JSONB DEFAULT '{}'::jsonb,

    -- Slug must be lowercase alphanumeric with hyphens
    CONSTRAINT check_team_slug_format CHECK (slug ~ '^[a-z0-9][a-z0-9-]*[a-z0-9]$' OR slug ~ '^[a-z0-9]$')
);

-- Create team_memberships table
CREATE TABLE IF NOT EXISTS team_memberships (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    team_id UUID NOT NULL REFERENCES teams(id) ON DELETE CASCADE,
    user_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    role VARCHAR(20) NOT NULL DEFAULT 'member',
    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
    invited_by VARCHAR(255),

    -- Each user can only be a member of a team once
    CONSTRAINT unique_team_membership UNIQUE (team_id, user_id),

    -- Role must be one of: owner, admin, member
    CONSTRAINT check_team_role CHECK (role IN ('owner', 'admin', 'member'))
);

-- Add team_id column to projects table (nullable for migration compatibility)
ALTER TABLE projects ADD COLUMN IF NOT EXISTS team_id UUID REFERENCES teams(id) ON DELETE SET NULL;

-- Indexes for teams table
CREATE INDEX IF NOT EXISTS idx_teams_slug ON teams(slug);
CREATE INDEX IF NOT EXISTS idx_teams_created_by ON teams(created_by);
CREATE INDEX IF NOT EXISTS idx_teams_created_at ON teams(created_at);

-- Indexes for team_memberships table
CREATE INDEX IF NOT EXISTS idx_team_memberships_team_id ON team_memberships(team_id);
CREATE INDEX IF NOT EXISTS idx_team_memberships_user_id ON team_memberships(user_id);
CREATE INDEX IF NOT EXISTS idx_team_memberships_role ON team_memberships(role);
CREATE INDEX IF NOT EXISTS idx_team_memberships_team_role ON team_memberships(team_id, role);

-- Index for projects team_id
CREATE INDEX IF NOT EXISTS idx_projects_team_id ON projects(team_id);

-- Comments
COMMENT ON TABLE teams IS 'Teams serve as organizational containers for projects';
COMMENT ON COLUMN teams.slug IS 'URL-friendly unique identifier (lowercase alphanumeric with hyphens)';
COMMENT ON COLUMN teams.settings IS 'JSON object for team-specific settings';

COMMENT ON TABLE team_memberships IS 'Maps users to teams with their roles';
COMMENT ON COLUMN team_memberships.role IS 'User role in the team: owner, admin, or member';
COMMENT ON COLUMN team_memberships.invited_by IS 'Username of the user who invited this member';

COMMENT ON COLUMN projects.team_id IS 'Optional team that owns this project';