// retroDE_ps2 — tb_top_psmct32_feeder_scenes_demo (Ch331)
//
// FEEDER EXPRESSIVENESS: variable-size, multi-tile command-list scenes via the end-of-list
// flush (MP_FLUSH_ONLY). Ch330 proved "runtime command ingestion exists" with a fixed 4-prim
// list. This proves it SCALES to scene-level control: lists of DIFFERENT sizes — 3 (< the old
// TILE_PRIM_COUNT threshold), 6 (> it), and 8 (== FIFO_DEPTH) — each rendered in ONE pass across
// arbitrary tiles, switched at runtime with no reset/rebuild.
//
//   scene C1 : 3 prims in tiles {0,5,10}                 (proves a <TILE_PRIM_COUNT list renders)
//   scene C2 : 6 prims in tiles {0,3,5,9,12,15}          (proves a >TILE_PRIM_COUNT list renders in one pass)
//   scene C3 : 8 prims in tiles {0,1,2,3,12,13,14,15}    (proves a full FIFO_DEPTH list renders)
//
// PROOF per scene: every scene tile has blue pixels, every NON-scene tile is clean green, and
// records_emitted == the scene's prim count. The end-of-list flush fires the grid once per scene
// regardless of size; the old fixed threshold would have split C2/C3 across clearing passes.

`timescale 1ns/1ps

module tb_top_psmct32_feeder_scenes_demo;

    localparam int H_ACTIVE = 64, V_ACTIVE = 64;
    localparam real MARG = 0.12;
    localparam logic [1:0] C_RUN = 2'd1, C_READY = 2'd3;

    logic clk, rst_n;
    initial clk = 1'b0;
    always #5 clk = ~clk;

    logic        core_go;
    logic [7:0]  r, g, b;
    logic        hsync, vsync, de;
    logic        core_halt, dma_done_seen, frame_seen, raster_overflow;
    logic        frame_toggle, dma_done_toggle;
    logic        feeder_go_tb;

    top_psmct32_raster_demo_bram #(
        .H_ACTIVE(H_ACTIVE), .V_ACTIVE(V_ACTIVE),
        .VRAM_BYTES(32*1024), .PSMCT32_SWIZZLE(1'b0),
        .COMBINED_TAZ(1'b1), .TILE_LOCAL(1'b1), .TILE_COLS(4), .TILE_ROWS(4),
        .TILE_MULTIPRIM(1'b1), .TILE_PRIM_COUNT(4), .TILE_FIFO_DEPTH(8),
        .BIN_BUFFER_ENABLE(1'b1), .HEARTBEAT_SPLICE_ENABLE(1'b0),
        .FEEDER_ENABLE(1'b1), .FEEDER_STG_WORDS(256)
    ) dut (
        .clk(clk), .rst_n(rst_n), .core_go(core_go),
        .r(r), .g(g), .b(b), .hsync(hsync), .vsync(vsync), .de(de),
        .core_halt(core_halt), .dma_done_seen(dma_done_seen),
        .frame_seen(frame_seen), .raster_overflow(raster_overflow),
        .frame_toggle(frame_toggle), .dma_done_toggle(dma_done_toggle),
        .joy_a_pressed_i(1'b0), .joy_b_pressed_i(1'b0),
        .feeder_stg_we_i(1'b0), .feeder_stg_waddr_i(12'd0), .feeder_stg_wdata_i(64'd0),
        .feeder_go_i(feeder_go_tb),
        .feeder_ready_o(), .feeder_records_o(), .feeder_waits_o()
    );

    // ---- scanout frame capture (one frame, re-armed per scene) ----
    logic [7:0] cap_r[0:V_ACTIVE-1][0:H_ACTIVE-1], cap_g[0:V_ACTIVE-1][0:H_ACTIVE-1], cap_b[0:V_ACTIVE-1][0:H_ACTIVE-1];
    logic       cap_de[0:V_ACTIVE-1][0:H_ACTIVE-1];
    bit capture_armed;
    task automatic clear_cap;
        for (int y=0;y<V_ACTIVE;y++) for (int x=0;x<H_ACTIVE;x++) begin
            cap_r[y][x]=0; cap_g[y][x]=0; cap_b[y][x]=0; cap_de[y][x]=0;
        end
    endtask
    initial begin clear_cap(); capture_armed=1'b0; end
    logic [31:0] hcnt_d, vcnt_d;
    always_ff @(posedge clk) begin
        if (!rst_n) begin hcnt_d<=0; vcnt_d<=0; end
        else begin hcnt_d<=32'(dut.u_pcrtc.hcnt); vcnt_d<=32'(dut.u_pcrtc.vcnt); end
    end
    always_ff @(posedge clk)
        if (rst_n && capture_armed && de && (vcnt_d<V_ACTIVE) && (hcnt_d<H_ACTIVE)) begin
            cap_r[vcnt_d][hcnt_d]<=r; cap_g[vcnt_d][hcnt_d]<=g; cap_b[vcnt_d][hcnt_d]<=b; cap_de[vcnt_d][hcnt_d]<=1'b1;
        end

    function automatic int blue_in_box(input int bx0, input int by0);
        int n; begin n=0;
            for (int y=by0;y<by0+16;y++) for (int x=bx0;x<bx0+16;x++)
                if (cap_de[y][x] && cap_b[y][x]===8'hFF && cap_r[y][x]===8'h00 && cap_g[y][x]===8'h00) n++;
            blue_in_box = n;
        end
    endfunction

    task automatic capture_frame;
        clear_cap();
        @(posedge dut.u_pcrtc.end_of_frame); @(posedge clk); capture_armed=1'b1;
        @(posedge dut.u_pcrtc.end_of_frame); @(posedge clk); capture_armed=1'b0;
    endtask

    int errors;

    // verify the captured frame: scene tiles (mask bit set) have blue, all others are clean.
    task automatic check_scene(input string label, input logic [15:0] mask, input int exp_records);
        int nb, scene_n; scene_n = 0;
        for (int t=0;t<16;t++) begin
            nb = blue_in_box((t%4)*16, (t/4)*16);
            if (mask[t]) begin
                scene_n++;
                if (nb < 15) begin $error("[%s] tile %0d in scene but only %0d blue px (not rendered)", label, t, nb); errors++; end
            end else begin
                if (nb != 0) begin $error("[%s] tile %0d NOT in scene but has %0d blue px (stray render)", label, t, nb); errors++; end
            end
        end
        if (int'(dut.feeder_records) != exp_records)
            begin $error("[%s] records=%0d (want %0d)", label, int'(dut.feeder_records), exp_records); errors++; end
        $display("[%s] %0d scene tiles painted, all others clean, records=%0d", label, scene_n, int'(dut.feeder_records));
    endtask

    task automatic stage_and_run(input string memfile);
        $readmemh(memfile, dut.g_feeder.feeder_stg);
        @(negedge clk); feeder_go_tb = 1'b1; @(negedge clk); feeder_go_tb = 1'b0;
        wait (dut.g_feeder.cst == C_RUN);
        wait (dut.g_feeder.cst == C_READY);
        capture_frame();
    endtask

    initial begin
        errors=0; feeder_go_tb=1'b0;
        // scene C1 is the power-up list (loaded into staging); it auto-runs after the bootlet upload.
        $readmemh(`FEEDER_SCENE_C1_FILE, dut.g_feeder.feeder_stg);

        rst_n=1'b0; core_go=1'b0;
        repeat(4) @(posedge clk); rst_n=1'b1; repeat(8) @(posedge clk);
        @(negedge clk); core_go=1'b1; @(negedge clk); core_go=1'b0;
        wait (core_halt==1'b1); repeat(4) @(posedge clk);
        wait (dma_done_seen==1'b1); repeat(10) @(posedge clk);
        if (dut.xfer_busy==1'b1) wait (dut.xfer_busy==1'b0);

        // C1 (3 prims, < TILE_PRIM_COUNT) — auto-run
        wait (dut.g_feeder.cst == C_READY);
        capture_frame();
        check_scene("C1 (3 prims, tiles 0/5/10)",        16'h0421, 3);

        // C2 (6 prims, > TILE_PRIM_COUNT) — runtime swap
        stage_and_run(`FEEDER_SCENE_C2_FILE);
        check_scene("C2 (6 prims, tiles 0/3/5/9/12/15)",  16'h9229, 6);

        // C3 (8 prims, == FIFO_DEPTH) — runtime swap
        stage_and_run(`FEEDER_SCENE_C3_FILE);
        check_scene("C3 (8 prims, tiles 0-3/12-15)",      16'hF00F, 8);

        if (raster_overflow) begin $error("raster_overflow set"); errors++; end
        if (!core_halt)      begin $error("core_halt low"); errors++; end

        $display("[tb_top_psmct32_feeder_scenes_demo] errors=%0d", errors);
        if (errors==0) $display("[tb_top_psmct32_feeder_scenes_demo] PASS");
        else           $display("[tb_top_psmct32_feeder_scenes_demo] FAIL");
        $finish;
    end

    initial begin #1200000000; $error("[tb_top_psmct32_feeder_scenes_demo] TIMEOUT"); $finish; end
endmodule : tb_top_psmct32_feeder_scenes_demo
