local db_core = require('db_modules.db_core')
local ffi = require('ffi')
local json = require('cjson')

local M = {}

-- FFI definitions for quantum operations
ffi.cdef[[
    typedef struct QuantumState QuantumState;
    typedef struct QuantumCircuit QuantumCircuit;
    
    QuantumState* quantum_new_state(int num_qubits);
    void quantum_free_state(QuantumState* state);
    
    QuantumCircuit* quantum_new_circuit(int num_qubits);
    void quantum_free_circuit(QuantumCircuit* circuit);
    
    void quantum_h(QuantumCircuit* circuit, int qubit);
    void quantum_cx(QuantumCircuit* circuit, int control, int target);
    void quantum_measure(QuantumCircuit* circuit, int qubit);
    
    void quantum_run_circuit(QuantumCircuit* circuit, QuantumState* state);
    double quantum_get_probability(QuantumState* state, int basis_state);
]]

-- Create quantum DB process
local process = db_core.create_db_process('quantum_db', {
    num_qubits = 8,
    max_depth = 100,
    optimization_level = 1
})

-- Initialize quantum DB
function M.init(opts)
    opts = opts or {}
    process.num_qubits = opts.num_qubits or 8
    process.max_depth = opts.max_depth or 100
    process.optimization_level = opts.optimization_level or 1
    
    -- Initialize quantum state and circuit
    process.state = ffi.gc(
        ffi.C.quantum_new_state(process.num_qubits),
        ffi.C.quantum_free_state
    )
    
    process.circuit = ffi.gc(
        ffi.C.quantum_new_circuit(process.num_qubits),
        ffi.C.quantum_free_circuit
    )
    
    -- Record initialization metric
    process:record_metric('init', 1)
    
    -- Apply current tuning parameters
    local params = process._tuning_params
    if params.optimization_level then
        process.optimization_level = params.optimization_level
    end
    
    return true
end

-- Create quantum superposition
function M.create_superposition(qubit)
    if qubit >= process.num_qubits then
        error(string.format("Qubit index %d out of range", qubit))
    end
    
    ffi.C.quantum_h(process.circuit, qubit)
    process:record_metric('gate_h', 1)
    return true
end

-- Apply CNOT gate
function M.apply_cnot(control, target)
    if math.max(control, target) >= process.num_qubits then
        error("Qubit indices out of range")
    end
    
    ffi.C.quantum_cx(process.circuit, control, target)
    process:record_metric('gate_cx', 1)
    return true
end

-- Measure quantum state
function M.measure(qubit)
    if qubit >= process.num_qubits then
        error(string.format("Qubit index %d out of range", qubit))
    end
    
    ffi.C.quantum_measure(process.circuit, qubit)
    process:record_metric('measure', 1)
    return true
end

-- Run quantum circuit
function M.run_circuit()
    ffi.C.quantum_run_circuit(process.circuit, process.state)
    process:record_metric('run_circuit', 1)
    
    -- Get probabilities for all basis states
    local probabilities = {}
    for i = 0, (1 << process.num_qubits) - 1 do
        probabilities[i] = ffi.C.quantum_get_probability(process.state, i)
    end
    
    return probabilities
end

-- Store quantum circuit
function M.store_circuit(name, metadata)
    -- Get latest tuning parameters
    process:update_tuning()
    
    -- Store circuit configuration
    local circuit_data = {
        num_qubits = process.num_qubits,
        optimization_level = process.optimization_level,
        metadata = metadata
    }
    
    -- Use LMDB to store circuit data
    -- Implementation depends on your storage needs
    
    process:record_metric('store_circuit', 1)
    return true
end

-- Cleanup
function M.shutdown()
    -- Cleanup is handled by FFI garbage collection
    process:record_metric('shutdown', 1)
    return true
end

return M
