-- Core Role/Permission System
-- Provides granular access control with default roles and custom role support

-- Permission categories
CREATE TYPE permission_category AS ENUM (
    'platform',      -- Platform-wide permissions
    'community',     -- Community management
    'proposals',     -- Proposal lifecycle
    'voting',        -- Voting configuration
    'moderation',    -- Content moderation
    'plugins',       -- Plugin management
    'users',         -- User management
    'integrations'   -- External integrations
);

-- Core permissions table
CREATE TABLE permissions (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    name VARCHAR(100) NOT NULL UNIQUE,
    category permission_category NOT NULL,
    description TEXT,
    is_system BOOLEAN NOT NULL DEFAULT FALSE, -- System permissions can't be deleted
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- Roles table (platform-level and community-level)
CREATE TABLE roles (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    name VARCHAR(100) NOT NULL,
    display_name VARCHAR(100) NOT NULL,
    description TEXT,
    color VARCHAR(7), -- Hex color for UI
    community_id UUID REFERENCES communities(id) ON DELETE CASCADE, -- NULL = platform role
    is_system BOOLEAN NOT NULL DEFAULT FALSE, -- System roles can't be deleted
    is_default BOOLEAN NOT NULL DEFAULT FALSE, -- Default role for new members
    priority INT NOT NULL DEFAULT 0, -- Higher = more authority (for display/conflict resolution)
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    UNIQUE(name, community_id)
);

-- Role permissions (many-to-many)
CREATE TABLE role_permissions (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    role_id UUID NOT NULL REFERENCES roles(id) ON DELETE CASCADE,
    permission_id UUID NOT NULL REFERENCES permissions(id) ON DELETE CASCADE,
    granted BOOLEAN NOT NULL DEFAULT TRUE, -- Can explicitly deny
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    UNIQUE(role_id, permission_id)
);

-- User roles (many-to-many, scoped to community or platform)
CREATE TABLE user_roles (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    user_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    role_id UUID NOT NULL REFERENCES roles(id) ON DELETE CASCADE,
    community_id UUID REFERENCES communities(id) ON DELETE CASCADE, -- NULL = platform role
    granted_by UUID REFERENCES users(id),
    granted_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    expires_at TIMESTAMPTZ, -- Optional expiration
    UNIQUE(user_id, role_id, community_id)
);

-- Insert default permissions
INSERT INTO permissions (name, category, description, is_system) VALUES
    -- Platform permissions
    ('platform.admin', 'platform', 'Full platform administration access', TRUE),
    ('platform.settings', 'platform', 'Manage platform settings', TRUE),
    ('platform.users.view', 'users', 'View all users', TRUE),
    ('platform.users.manage', 'users', 'Manage user accounts', TRUE),
    ('platform.users.ban', 'users', 'Ban/suspend users', TRUE),
    
    -- Community permissions
    ('community.create', 'community', 'Create new communities', TRUE),
    ('community.settings', 'community', 'Manage community settings', TRUE),
    ('community.members.view', 'community', 'View community members', TRUE),
    ('community.members.manage', 'community', 'Manage community membership', TRUE),
    ('community.members.invite', 'community', 'Invite new members', TRUE),
    ('community.roles.manage', 'community', 'Create and manage roles', TRUE),
    
    -- Proposal permissions
    ('proposals.create', 'proposals', 'Create proposals', TRUE),
    ('proposals.edit.own', 'proposals', 'Edit own proposals', TRUE),
    ('proposals.edit.any', 'proposals', 'Edit any proposal', TRUE),
    ('proposals.delete.own', 'proposals', 'Delete own proposals', TRUE),
    ('proposals.delete.any', 'proposals', 'Delete any proposal', TRUE),
    ('proposals.moderate', 'proposals', 'Moderate proposal lifecycle', TRUE),
    
    -- Voting permissions
    ('voting.vote', 'voting', 'Cast votes', TRUE),
    ('voting.configure', 'voting', 'Configure voting methods', TRUE),
    ('voting.methods.manage', 'voting', 'Enable/disable voting methods', TRUE),
    ('voting.results.view', 'voting', 'View detailed voting results', TRUE),
    
    -- Moderation permissions
    ('moderation.comments.edit', 'moderation', 'Edit comments', TRUE),
    ('moderation.comments.delete', 'moderation', 'Delete comments', TRUE),
    ('moderation.users.warn', 'moderation', 'Warn users', TRUE),
    ('moderation.users.mute', 'moderation', 'Mute users', TRUE),
    ('moderation.users.kick', 'moderation', 'Remove users from community', TRUE),
    ('moderation.log.view', 'moderation', 'View moderation log', TRUE),
    
    -- Plugin permissions
    ('plugins.view', 'plugins', 'View installed plugins', TRUE),
    ('plugins.install', 'plugins', 'Install new plugins', TRUE),
    ('plugins.configure', 'plugins', 'Configure plugin settings', TRUE),
    ('plugins.uninstall', 'plugins', 'Uninstall plugins', TRUE),
    
    -- Delegation permissions
    ('delegation.delegate', 'voting', 'Delegate votes to others', TRUE),
    ('delegation.receive', 'voting', 'Receive delegated votes', TRUE),
    
    -- Integration permissions
    ('integrations.view', 'integrations', 'View integrations', TRUE),
    ('integrations.configure', 'integrations', 'Configure integrations', TRUE)
ON CONFLICT (name) DO NOTHING;

-- Insert default platform roles
INSERT INTO roles (name, display_name, description, is_system, priority, community_id) VALUES
    ('platform_admin', 'Platform Admin', 'Full platform control', TRUE, 1000, NULL),
    ('platform_moderator', 'Platform Moderator', 'Platform-wide moderation', TRUE, 500, NULL),
    ('user', 'User', 'Standard registered user', TRUE, 100, NULL)
ON CONFLICT (name, community_id) DO NOTHING;

-- Assign all permissions to platform_admin
INSERT INTO role_permissions (role_id, permission_id, granted)
SELECT r.id, p.id, TRUE
FROM roles r, permissions p
WHERE r.name = 'platform_admin' AND r.community_id IS NULL
ON CONFLICT (role_id, permission_id) DO NOTHING;

-- Assign moderation permissions to platform_moderator
INSERT INTO role_permissions (role_id, permission_id, granted)
SELECT r.id, p.id, TRUE
FROM roles r, permissions p
WHERE r.name = 'platform_moderator' AND r.community_id IS NULL
  AND p.category IN ('moderation', 'community')
ON CONFLICT (role_id, permission_id) DO NOTHING;

-- Assign basic permissions to user role
INSERT INTO role_permissions (role_id, permission_id, granted)
SELECT r.id, p.id, TRUE
FROM roles r, permissions p
WHERE r.name = 'user' AND r.community_id IS NULL
  AND p.name IN ('community.create', 'proposals.create', 'proposals.edit.own', 
                 'proposals.delete.own', 'voting.vote', 'delegation.delegate',
                 'community.members.view', 'plugins.view', 'voting.results.view')
ON CONFLICT (role_id, permission_id) DO NOTHING;

-- Indexes
CREATE INDEX idx_permissions_category ON permissions(category);
CREATE INDEX idx_roles_community ON roles(community_id);
CREATE INDEX idx_roles_system ON roles(is_system);
CREATE INDEX idx_role_permissions_role ON role_permissions(role_id);
CREATE INDEX idx_user_roles_user ON user_roles(user_id);
CREATE INDEX idx_user_roles_role ON user_roles(role_id);
CREATE INDEX idx_user_roles_community ON user_roles(community_id);

-- Triggers
CREATE TRIGGER roles_updated_at BEFORE UPDATE ON roles
    FOR EACH ROW EXECUTE FUNCTION update_updated_at();

-- Function to check if user has permission
CREATE OR REPLACE FUNCTION user_has_permission(
    p_user_id UUID,
    p_permission_name VARCHAR,
    p_community_id UUID DEFAULT NULL
) RETURNS BOOLEAN AS $$
DECLARE
    has_perm BOOLEAN := FALSE;
BEGIN
    -- Check platform roles first
    SELECT EXISTS (
        SELECT 1 FROM user_roles ur
        JOIN role_permissions rp ON ur.role_id = rp.role_id
        JOIN permissions p ON rp.permission_id = p.id
        WHERE ur.user_id = p_user_id
          AND p.name = p_permission_name
          AND rp.granted = TRUE
          AND ur.community_id IS NULL
          AND (ur.expires_at IS NULL OR ur.expires_at > NOW())
    ) INTO has_perm;
    
    IF has_perm THEN RETURN TRUE; END IF;
    
    -- Check community roles if community_id provided
    IF p_community_id IS NOT NULL THEN
        SELECT EXISTS (
            SELECT 1 FROM user_roles ur
            JOIN role_permissions rp ON ur.role_id = rp.role_id
            JOIN permissions p ON rp.permission_id = p.id
            WHERE ur.user_id = p_user_id
              AND p.name = p_permission_name
              AND rp.granted = TRUE
              AND ur.community_id = p_community_id
              AND (ur.expires_at IS NULL OR ur.expires_at > NOW())
        ) INTO has_perm;
    END IF;
    
    RETURN has_perm;
END;
$$ LANGUAGE plpgsql;