// ----------------------------------------------------------------------
// Driver for AXI transactions
// ----------------------------------------------------------------------
class axi_driver extends uvm_driver; // #(axi_transaction);
    virtual `AXI_INTF.MANAGER m_if;
    virtual `AXI_INTF.SUBORDINATE s_if;
    agent_type_t agent_type;

    `uvm_component_utils(axi_driver)

    // --------------------------------------------------
    // Constructor
    function new(string name = "axi_driver", uvm_component parent = null);
        super.new(name, parent);
    endfunction

    // --------------------------------------------------
    // Set agent type
    function void set_agent_type(agent_type_t atype);
        agent_type = atype;
        `uvm_info("set_agent_type", $sformatf("Agent type set to %s", agent_type.name()), UVM_LOW)
    endfunction

    // --------------------------------------------------
    // Set virtual interfaces
    function void set_virtual_intefaces(virtual `AXI_INTF.MANAGER m_if_p,
                                        virtual `AXI_INTF.SUBORDINATE s_if_p);
        `uvm_info("set_virtual_intefaces", $sformatf("Setting virtual interfaces"), UVM_LOW)

        m_if = m_if_p;
        s_if = s_if_p;

        // if (m_if == null && s_if == null) begin
        //     `uvm_fatal("AXI_DRIVER", "Both MANAGER and SUBORDINATE interfaces are null")
        // end else if ((agent_type == MANAGER) && (m_if == null)) begin
        //     `uvm_error("AXI_DRIVER", $sformatf("MANAGER interface is null"))
        // end else if ((agent_type == SUBORDINATE) && (s_if == null)) begin
        //     `uvm_error("AXI_DRIVER", $sformatf("SUBORDINATE interface is null"))
        // end
    endfunction

    // --------------------------------------------------
    // Run phase
    virtual task run_phase(uvm_phase phase);
        `uvm_info("axi_driver", $sformatf("Running AXI driver: %s as %s",
            get_full_name(), agent_type.name()), UVM_LOW)

        if (agent_type == MANAGER) begin
            `uvm_info("axi_driver", $sformatf("Manager agent detected, driving transactions"), UVM_LOW)
            drive_transactions();
        end else if (agent_type == SUBORDINATE) begin
            `uvm_info("axi_driver", $sformatf("Subordinate agent detected, responding to transactions"), UVM_LOW)
            respond_to_transactions();
        end else begin
            `uvm_fatal("AXI_DRIVER", "Unknown agent type")
        end
    endtask

    // ------------------------------------------------------------
    task drive_transactions();
        if (m_if == null) begin
            `uvm_error("AXI_DRIVER", "MANAGER interface is null, cannot drive transactions")
        end
        forever begin
            `uvm_info("axi_driver", $sformatf("Starting to drive transactions for %s (rst_n = %0b)",
                get_full_name(), m_if.ARESETn), UVM_LOW)

            if (m_if.ARESETn == 0) begin
                `uvm_info("axi_driver", $sformatf("Waiting for reset to be released (rst_n = %0b)",
                    m_if.ARESETn), UVM_LOW)
                @(posedge m_if.ARESETn);
            end

            `uvm_info("axi_driver", $sformatf("Starting to drive transactions for %s (rst_n = %0b)",
                get_full_name(), m_if.ARESETn), UVM_LOW)

            while (m_if.ARESETn != 0) begin
                uvm_sequence_item txn;

                `uvm_info("axi_driver", $sformatf("Waiting for next transaction"), UVM_LOW)

                seq_item_port.get_next_item(txn);
                drive_item(txn);
                seq_item_port.item_done();
            end
        end
    endtask

    // ------------------------------------------------------------
    task drive_item(uvm_sequence_item txn);
        axi_transaction req;

        if (!$cast(req, txn)) begin
            `uvm_fatal("AXI_DRIVER", "Invalid transaction type")
        end

        `uvm_info("drive_item", $sformatf("Driving AXI transaction:\n%s", req.sprint()), UVM_LOW)
        @(posedge m_if.ACLK);
        m_if.AWVALID = 1;
        m_if.AWADDR  = req.addr;
        @(posedge m_if.ACLK);
        m_if.WDATA  = req.data;
        m_if.WSTRB  = req.strb;
        `uvm_info("drive_item", $sformatf("Driving AXI transaction done."), UVM_LOW)
    endtask

    // ------------------------------------------------------------
    task respond_to_transactions();
        forever begin
            @(posedge s_if.ARESETn);

            while (s_if.ARESETn != 0) begin
                @(posedge s_if.ACLK);

                @(negedge s_if.ACLK);
            end
        end
    endtask
endclass : axi_driver