-- ==========================================
-- Chat Switchboard - PostgreSQL Schema
-- ==========================================

-- Enable extensions
CREATE EXTENSION IF NOT EXISTS "uuid-ossp";
CREATE EXTENSION IF NOT EXISTS "pgcrypto";
CREATE EXTENSION IF NOT EXISTS "vector"; -- For embeddings (pgvector)

-- ==========================================
-- Core Tables
-- ==========================================

-- Users
CREATE TABLE users (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    username VARCHAR(50) UNIQUE NOT NULL,
    email VARCHAR(255) UNIQUE NOT NULL,
    password_hash TEXT NOT NULL,
    display_name VARCHAR(100),
    avatar_url TEXT,
    role VARCHAR(20) DEFAULT 'user', -- user, admin, moderator
    is_active BOOLEAN DEFAULT true,
    settings JSONB DEFAULT '{}'::jsonb,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
    updated_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
    last_login_at TIMESTAMP WITH TIME ZONE
);

CREATE INDEX idx_users_username ON users(username);
CREATE INDEX idx_users_email ON users(email);

-- API Configurations (user's API keys)
CREATE TABLE api_configs (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    user_id UUID REFERENCES users(id) ON DELETE CASCADE,
    name VARCHAR(100) NOT NULL, -- "OpenAI", "Claude", "Local Ollama"
    provider VARCHAR(50) NOT NULL, -- openai, anthropic, ollama, openrouter
    endpoint TEXT NOT NULL,
    api_key_encrypted TEXT, -- Encrypted at rest
    model_default VARCHAR(100),
    config JSONB DEFAULT '{}'::jsonb, -- Custom settings per provider
    is_active BOOLEAN DEFAULT true,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
    updated_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

CREATE INDEX idx_api_configs_user ON api_configs(user_id);

-- ==========================================
-- Feature 1: CHATS (User to LLM)
-- ==========================================

CREATE TABLE chats (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    user_id UUID REFERENCES users(id) ON DELETE CASCADE,
    title VARCHAR(500) NOT NULL,
    model VARCHAR(100), -- Current model for this chat
    api_config_id UUID REFERENCES api_configs(id) ON DELETE SET NULL,
    system_prompt TEXT,
    settings JSONB DEFAULT '{}'::jsonb, -- temperature, max_tokens, etc
    is_archived BOOLEAN DEFAULT false,
    is_pinned BOOLEAN DEFAULT false,
    folder VARCHAR(100), -- For organization
    tags TEXT[], -- For filtering
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
    updated_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

CREATE INDEX idx_chats_user ON chats(user_id);
CREATE INDEX idx_chats_updated ON chats(updated_at DESC);
CREATE INDEX idx_chats_tags ON chats USING GIN(tags);

CREATE TABLE chat_messages (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    chat_id UUID REFERENCES chats(id) ON DELETE CASCADE,
    role VARCHAR(20) NOT NULL, -- user, assistant, system, tool
    content TEXT NOT NULL,
    model VARCHAR(100), -- Which model generated this (for assistant)
    tokens_used INTEGER,
    tool_calls JSONB, -- Function calls made
    metadata JSONB DEFAULT '{}'::jsonb, -- thinking_blocks, attachments, etc
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

CREATE INDEX idx_chat_messages_chat ON chat_messages(chat_id, created_at);

-- Model routing history (for analytics/debugging)
CREATE TABLE model_routing_log (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    chat_id UUID REFERENCES chats(id) ON DELETE CASCADE,
    message_id UUID REFERENCES chat_messages(id) ON DELETE CASCADE,
    requested_model VARCHAR(100),
    routed_model VARCHAR(100),
    reason TEXT, -- "cost_optimization", "context_length", "manual", "fallback"
    latency_ms INTEGER,
    cost_usd NUMERIC(10, 6),
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

CREATE INDEX idx_routing_log_chat ON model_routing_log(chat_id);

-- ==========================================
-- Feature 2: CHANNELS (User to User + AI)
-- ==========================================

CREATE TABLE channels (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    name VARCHAR(100) UNIQUE NOT NULL,
    description TEXT,
    type VARCHAR(20) DEFAULT 'public', -- public, private, dm
    owner_id UUID REFERENCES users(id) ON DELETE SET NULL,
    settings JSONB DEFAULT '{}'::jsonb, -- ai_participants, webhooks, etc
    is_archived BOOLEAN DEFAULT false,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
    updated_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

CREATE INDEX idx_channels_name ON channels(name);
CREATE INDEX idx_channels_type ON channels(type);

-- Channel memberships
CREATE TABLE channel_members (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    channel_id UUID REFERENCES channels(id) ON DELETE CASCADE,
    user_id UUID REFERENCES users(id) ON DELETE CASCADE,
    role VARCHAR(20) DEFAULT 'member', -- owner, admin, member
    joined_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
    last_read_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
    UNIQUE(channel_id, user_id)
);

CREATE INDEX idx_channel_members_channel ON channel_members(channel_id);
CREATE INDEX idx_channel_members_user ON channel_members(user_id);

-- Channel messages
CREATE TABLE channel_messages (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    channel_id UUID REFERENCES channels(id) ON DELETE CASCADE,
    user_id UUID REFERENCES users(id) ON DELETE SET NULL, -- NULL for AI messages
    content TEXT NOT NULL,
    mentions JSONB, -- {users: [uuid], models: [name]}
    thread_id UUID REFERENCES channel_messages(id) ON DELETE CASCADE, -- For threading
    attachments JSONB, -- Files, images, etc
    reactions JSONB DEFAULT '{}'::jsonb, -- {emoji: [user_ids]}
    is_ai_message BOOLEAN DEFAULT false,
    ai_model VARCHAR(100), -- If AI generated
    edited_at TIMESTAMP WITH TIME ZONE,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

CREATE INDEX idx_channel_messages_channel ON channel_messages(channel_id, created_at DESC);
CREATE INDEX idx_channel_messages_thread ON channel_messages(thread_id);
CREATE INDEX idx_channel_messages_mentions ON channel_messages USING GIN(mentions);

-- ==========================================
-- Feature 3: NOTES & KNOWLEDGE BASES
-- ==========================================

CREATE TABLE notes (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    user_id UUID REFERENCES users(id) ON DELETE CASCADE,
    title VARCHAR(500) NOT NULL,
    content TEXT NOT NULL,
    content_type VARCHAR(20) DEFAULT 'markdown', -- markdown, html, plain
    folder VARCHAR(100),
    tags TEXT[],
    is_pinned BOOLEAN DEFAULT false,
    is_shared BOOLEAN DEFAULT false,
    share_token UUID UNIQUE DEFAULT uuid_generate_v4(),
    parent_note_id UUID REFERENCES notes(id) ON DELETE SET NULL, -- For hierarchies
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
    updated_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

CREATE INDEX idx_notes_user ON notes(user_id);
CREATE INDEX idx_notes_updated ON notes(updated_at DESC);
CREATE INDEX idx_notes_tags ON notes USING GIN(tags);
CREATE INDEX idx_notes_share_token ON notes(share_token) WHERE is_shared = true;

-- Knowledge Bases (Collections of documents)
CREATE TABLE knowledge_bases (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    user_id UUID REFERENCES users(id) ON DELETE CASCADE,
    name VARCHAR(200) NOT NULL,
    description TEXT,
    embedding_model VARCHAR(100) DEFAULT 'text-embedding-ada-002',
    settings JSONB DEFAULT '{}'::jsonb, -- chunk_size, overlap, etc
    is_public BOOLEAN DEFAULT false,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
    updated_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

CREATE INDEX idx_knowledge_bases_user ON knowledge_bases(user_id);

-- Documents in knowledge bases
CREATE TABLE kb_documents (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    kb_id UUID REFERENCES knowledge_bases(id) ON DELETE CASCADE,
    filename VARCHAR(500) NOT NULL,
    content TEXT NOT NULL,
    content_type VARCHAR(50), -- application/pdf, text/markdown, etc
    file_size INTEGER,
    metadata JSONB DEFAULT '{}'::jsonb,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

CREATE INDEX idx_kb_documents_kb ON kb_documents(kb_id);

-- Document chunks (for RAG)
CREATE TABLE kb_chunks (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    document_id UUID REFERENCES kb_documents(id) ON DELETE CASCADE,
    kb_id UUID REFERENCES knowledge_bases(id) ON DELETE CASCADE,
    content TEXT NOT NULL,
    embedding vector(1536), -- For pgvector similarity search
    chunk_index INTEGER,
    metadata JSONB DEFAULT '{}'::jsonb,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

CREATE INDEX idx_kb_chunks_document ON kb_chunks(document_id);
CREATE INDEX idx_kb_chunks_embedding ON kb_chunks USING ivfflat (embedding vector_cosine_ops);

-- ==========================================
-- Feature 4: PLUGIN ORCHESTRATION
-- ==========================================

-- Installed extensions/plugins
CREATE TABLE extensions (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    name VARCHAR(100) UNIQUE NOT NULL,
    version VARCHAR(20) NOT NULL,
    author VARCHAR(100),
    description TEXT,
    runtime VARCHAR(20), -- python, go, node, rust
    entry_point TEXT NOT NULL,
    port INTEGER,
    manifest JSONB NOT NULL, -- Full extension.json
    is_enabled BOOLEAN DEFAULT true,
    is_system BOOLEAN DEFAULT false, -- Core extensions
    install_source VARCHAR(200), -- URL or marketplace ID
    installed_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

CREATE INDEX idx_extensions_enabled ON extensions(is_enabled);

-- Extension tools/functions
CREATE TABLE extension_tools (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    extension_id UUID REFERENCES extensions(id) ON DELETE CASCADE,
    name VARCHAR(100) NOT NULL,
    description TEXT,
    parameters_schema JSONB NOT NULL, -- JSON Schema
    response_schema JSONB,
    is_enabled BOOLEAN DEFAULT true,
    UNIQUE(extension_id, name)
);

CREATE INDEX idx_extension_tools_extension ON extension_tools(extension_id);

-- Tool usage log (for analytics)
CREATE TABLE tool_usage_log (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    tool_id UUID REFERENCES extension_tools(id) ON DELETE SET NULL,
    user_id UUID REFERENCES users(id) ON DELETE SET NULL,
    chat_id UUID REFERENCES chats(id) ON DELETE SET NULL,
    channel_id UUID REFERENCES channels(id) ON DELETE SET NULL,
    input_params JSONB,
    output_result JSONB,
    execution_time_ms INTEGER,
    success BOOLEAN,
    error_message TEXT,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

CREATE INDEX idx_tool_usage_tool ON tool_usage_log(tool_id);
CREATE INDEX idx_tool_usage_user ON tool_usage_log(user_id);

-- ==========================================
-- Feature 5: WORKFLOWS (Unique Feature!)
-- ==========================================

-- Workflow definitions (DAG of AI operations)
CREATE TABLE workflows (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    user_id UUID REFERENCES users(id) ON DELETE CASCADE,
    name VARCHAR(200) NOT NULL,
    description TEXT,
    graph JSONB NOT NULL, -- Node-edge DAG structure
    input_schema JSONB, -- Expected inputs
    output_schema JSONB, -- Expected outputs
    is_public BOOLEAN DEFAULT false,
    is_template BOOLEAN DEFAULT false,
    tags TEXT[],
    usage_count INTEGER DEFAULT 0,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
    updated_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

CREATE INDEX idx_workflows_user ON workflows(user_id);
CREATE INDEX idx_workflows_public ON workflows(is_public) WHERE is_public = true;
CREATE INDEX idx_workflows_tags ON workflows USING GIN(tags);

-- Workflow executions
CREATE TABLE workflow_executions (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    workflow_id UUID REFERENCES workflows(id) ON DELETE CASCADE,
    user_id UUID REFERENCES users(id) ON DELETE SET NULL,
    input_data JSONB,
    output_data JSONB,
    status VARCHAR(20), -- running, completed, failed
    steps JSONB, -- Execution trace
    total_cost_usd NUMERIC(10, 6),
    total_time_ms INTEGER,
    error_message TEXT,
    started_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
    completed_at TIMESTAMP WITH TIME ZONE
);

CREATE INDEX idx_workflow_executions_workflow ON workflow_executions(workflow_id);
CREATE INDEX idx_workflow_executions_user ON workflow_executions(user_id);

-- ==========================================
-- Shared/Utility Tables
-- ==========================================

-- File uploads
CREATE TABLE files (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    user_id UUID REFERENCES users(id) ON DELETE CASCADE,
    filename VARCHAR(500) NOT NULL,
    content_type VARCHAR(100),
    file_size INTEGER,
    storage_path TEXT NOT NULL, -- S3/local path
    is_public BOOLEAN DEFAULT false,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

CREATE INDEX idx_files_user ON files(user_id);

-- Webhooks
CREATE TABLE webhooks (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    user_id UUID REFERENCES users(id) ON DELETE CASCADE,
    name VARCHAR(100),
    url TEXT NOT NULL,
    events TEXT[] NOT NULL, -- chat.message, channel.message, etc
    secret VARCHAR(100),
    is_active BOOLEAN DEFAULT true,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

CREATE INDEX idx_webhooks_user ON webhooks(user_id);

-- Audit log
CREATE TABLE audit_log (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    user_id UUID REFERENCES users(id) ON DELETE SET NULL,
    action VARCHAR(100) NOT NULL,
    resource_type VARCHAR(50),
    resource_id UUID,
    metadata JSONB,
    ip_address INET,
    user_agent TEXT,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW()
);

CREATE INDEX idx_audit_log_user ON audit_log(user_id);
CREATE INDEX idx_audit_log_created ON audit_log(created_at DESC);

-- ==========================================
-- Functions & Triggers
-- ==========================================

-- Auto-update updated_at timestamps
CREATE OR REPLACE FUNCTION update_updated_at()
RETURNS TRIGGER AS $$
BEGIN
    NEW.updated_at = NOW();
    RETURN NEW;
END;
$$ LANGUAGE plpgsql;

CREATE TRIGGER users_updated_at BEFORE UPDATE ON users
    FOR EACH ROW EXECUTE FUNCTION update_updated_at();
CREATE TRIGGER chats_updated_at BEFORE UPDATE ON chats
    FOR EACH ROW EXECUTE FUNCTION update_updated_at();
CREATE TRIGGER channels_updated_at BEFORE UPDATE ON channels
    FOR EACH ROW EXECUTE FUNCTION update_updated_at();
CREATE TRIGGER notes_updated_at BEFORE UPDATE ON notes
    FOR EACH ROW EXECUTE FUNCTION update_updated_at();
CREATE TRIGGER knowledge_bases_updated_at BEFORE UPDATE ON knowledge_bases
    FOR EACH ROW EXECUTE FUNCTION update_updated_at();
CREATE TRIGGER workflows_updated_at BEFORE UPDATE ON workflows
    FOR EACH ROW EXECUTE FUNCTION update_updated_at();

-- Increment workflow usage count
CREATE OR REPLACE FUNCTION increment_workflow_usage()
RETURNS TRIGGER AS $$
BEGIN
    UPDATE workflows SET usage_count = usage_count + 1 WHERE id = NEW.workflow_id;
    RETURN NEW;
END;
$$ LANGUAGE plpgsql;

CREATE TRIGGER workflow_executions_insert AFTER INSERT ON workflow_executions
    FOR EACH ROW EXECUTE FUNCTION increment_workflow_usage();