use super::harness::*;
use std::collections::HashMap;

fn parse_params(output: &str) -> HashMap<String, f64> {
    let mut params = HashMap::new();
    let parts: Vec<&str> = output.trim_start_matches('/').split('/').collect();
    let mut i = 0;
    while i + 1 < parts.len() {
        if let Ok(v) = parts[i + 1].parse::<f64>() {
            params.insert(parts[i].to_string(), v);
        }
        i += 2;
    }
    params
}

fn get_deltas(outputs: &[String]) -> Vec<f64> {
    outputs
        .iter()
        .map(|o| parse_params(o).get("delta").copied().unwrap_or(0.0))
        .collect()
}

fn get_gates(outputs: &[String]) -> Vec<f64> {
    outputs
        .iter()
        .map(|o| parse_params(o).get("gate").copied().unwrap_or(0.0))
        .collect()
}

fn get_sounds(outputs: &[String]) -> Vec<String> {
    outputs
        .iter()
        .map(|o| {
            let parts: Vec<&str> = o.trim_start_matches('/').split('/').collect();
            if parts.len() >= 2 && parts[0] == "sound" {
                parts[1].to_string()
            } else {
                String::new()
            }
        })
        .collect()
}

const EPSILON: f64 = 1e-9;

fn approx_eq(a: f64, b: f64) -> bool {
    (a - b).abs() < EPSILON
}

#[test]
fn stepdur_baseline() {
    let f = run("stepdur");
    assert!(approx_eq(stack_float(&f), 0.125));
}

#[test]
fn single_emit() {
    let outputs = expect_outputs(r#""kick" snd ."#, 1);
    let deltas = get_deltas(&outputs);
    assert!(approx_eq(deltas[0], 0.0), "single emit at start should have delta 0");
}

#[test]
fn multiple_emits_all_at_zero() {
    let outputs = expect_outputs(r#""kick" snd . . . ."#, 4);
    let deltas = get_deltas(&outputs);
    for (i, delta) in deltas.iter().enumerate() {
        assert!(approx_eq(*delta, 0.0), "emit {}: expected delta 0, got {}", i, delta);
    }
}

#[test]
fn sound_persists() {
    let outputs = expect_outputs(r#""kick" snd . . "hat" snd . ."#, 4);
    let sounds = get_sounds(&outputs);
    assert_eq!(sounds[0], "kick");
    assert_eq!(sounds[1], "kick");
    assert_eq!(sounds[2], "hat");
    assert_eq!(sounds[3], "hat");
}

#[test]
fn alternating_sounds() {
    let outputs = expect_outputs(r#""kick" snd . "snare" snd . "kick" snd . "snare" snd ."#, 4);
    let sounds = get_sounds(&outputs);
    assert_eq!(sounds, vec!["kick", "snare", "kick", "snare"]);
}

#[test]
fn gate_is_step_duration() {
    let outputs = expect_outputs(r#""kick" snd ."#, 1);
    let gates = get_gates(&outputs);
    assert!(approx_eq(gates[0], 0.5), "gate should be 4 * step_duration (0.5), got {}", gates[0]);
}

#[test]
fn cycle_picks_by_runs() {
    for runs in 0..4 {
        let ctx = ctx_with(|c| c.runs = runs);
        let f = forth();
        let outputs = f.evaluate(r#""kick" snd ( . ) ( ) 2 cycle"#, &ctx).unwrap();
        if runs % 2 == 0 {
            assert_eq!(outputs.len(), 1, "runs={}: emit should be picked", runs);
        } else {
            assert_eq!(outputs.len(), 0, "runs={}: no-op should be picked", runs);
        }
    }
}

#[test]
fn pcycle_picks_by_iter() {
    for iter in 0..4 {
        let ctx = ctx_with(|c| c.iter = iter);
        let f = forth();
        let outputs = f.evaluate(r#""kick" snd ( . ) ( ) 2 pcycle"#, &ctx).unwrap();
        if iter % 2 == 0 {
            assert_eq!(outputs.len(), 1, "iter={}: emit should be picked", iter);
        } else {
            assert_eq!(outputs.len(), 0, "iter={}: no-op should be picked", iter);
        }
    }
}

#[test]
fn cycle_with_sounds() {
    for runs in 0..3 {
        let ctx = ctx_with(|c| c.runs = runs);
        let f = forth();
        let outputs = f.evaluate(
            r#"( "kick" snd . ) ( "hat" snd . ) ( "snare" snd . ) 3 cycle"#,
            &ctx
        ).unwrap();
        assert_eq!(outputs.len(), 1, "runs={}: expected 1 output", runs);
        let sounds = get_sounds(&outputs);
        let expected = ["kick", "hat", "snare"][runs % 3];
        assert_eq!(sounds[0], expected, "runs={}: expected {}", runs, expected);
    }
}


#[test]
fn at_single_delta() {
    let outputs = expect_outputs(r#"0.5 at "kick" snd ."#, 1);
    let deltas = get_deltas(&outputs);
    let step_dur = 0.125;
    let sr: f64 = 48000.0;
    assert!(approx_eq(deltas[0], (0.5 * step_dur * sr).round()), "expected delta at 0.5 of step, got {}", deltas[0]);
}

#[test]
fn at_list_deltas() {
    let outputs = expect_outputs(r#"0 0.5 at "kick" snd ."#, 2);
    let deltas = get_deltas(&outputs);
    let step_dur = 0.125;
    let sr: f64 = 48000.0;
    assert!(approx_eq(deltas[0], 0.0), "expected delta 0, got {}", deltas[0]);
    assert!(approx_eq(deltas[1], (0.5 * step_dur * sr).round()), "expected delta at 0.5 of step, got {}", deltas[1]);
}

#[test]
fn at_three_deltas() {
    let outputs = expect_outputs(r#"0 0.33 0.67 at "kick" snd ."#, 3);
    let deltas = get_deltas(&outputs);
    let step_dur = 0.125;
    let sr: f64 = 48000.0;
    assert!(approx_eq(deltas[0], 0.0), "expected delta 0");
    assert!(approx_eq(deltas[1], (0.33 * step_dur * sr).round()), "expected delta at 0.33 of step");
    assert!(approx_eq(deltas[2], (0.67 * step_dur * sr).round()), "expected delta at 0.67 of step");
}

#[test]
fn at_persists_across_emits() {
    // With at as a loop, each at...block is independent.
    // Two separate at blocks each emit twice.
    let outputs = expect_outputs(r#"0 0.5 at "kick" snd . 0 0.5 at "hat" snd ."#, 4);
    let sounds = get_sounds(&outputs);
    assert_eq!(sounds, vec!["kick", "kick", "hat", "hat"]);
}


#[test]
fn at_reset_with_zero() {
    let outputs = expect_outputs(r#"0 0.5 at "kick" snd . 0.0 at "hat" snd ."#, 3);
    let sounds = get_sounds(&outputs);
    assert_eq!(sounds, vec!["kick", "kick", "hat"]);
}

#[test]
fn clear_resets_at_deltas() {
    let outputs = expect_outputs(r#"0 0.5 at "kick" snd . clear "hat" snd ."#, 3);
    let sounds = get_sounds(&outputs);
    assert_eq!(sounds, vec!["kick", "kick", "hat"]);
    let deltas = get_deltas(&outputs);
    assert!(approx_eq(deltas[2], 0.0), "after clear, hat should emit at delta 0, got {}", deltas[2]);
}

#[test]
fn at_records_selected_spans() {
    use cagire::forth::ExecutionTrace;

    let f = forth();
    let mut trace = ExecutionTrace::default();
    let script = r#"0 0.5 0.75 at "kick" snd ."#;
    f.evaluate_with_trace(script, &default_ctx(), &mut trace).unwrap();

    // With at-loop, each iteration emits once: 3 sound spans total
    assert_eq!(trace.selected_spans.len(), 3, "expected 3 selected spans (1 sound per iteration)");
}

fn get_notes(outputs: &[String]) -> Vec<f64> {
    outputs
        .iter()
        .map(|o| parse_params(o).get("note").copied().unwrap_or(0.0))
        .collect()
}

#[test]
fn at_loop_with_cycle_notes() {
    // at-loop + cycle replaces at + arp: cycle advances per subdivision
    let ctx = ctx_with(|c| c.runs = 0);
    let f = forth();
    let outputs = f.evaluate(r#"0 0.25 0.5 0.75 at sine snd [ c4 e4 g4 b4 ] cycle note ."#, &ctx).unwrap();
    assert_eq!(outputs.len(), 4);
    let notes = get_notes(&outputs);
    assert!(approx_eq(notes[0], 60.0));
    assert!(approx_eq(notes[1], 64.0));
    assert!(approx_eq(notes[2], 67.0));
    assert!(approx_eq(notes[3], 71.0));
    let deltas = get_deltas(&outputs);
    let step_dur = 0.125;
    let sr: f64 = 48000.0;
    assert!(approx_eq(deltas[0], 0.0));
    assert!(approx_eq(deltas[1], (0.25 * step_dur * sr).round()));
    assert!(approx_eq(deltas[2], (0.5 * step_dur * sr).round()));
    assert!(approx_eq(deltas[3], (0.75 * step_dur * sr).round()));
}

#[test]
fn at_loop_cycle_wraps() {
    // cycle inside at-loop wraps when more deltas than items
    let ctx = ctx_with(|c| c.runs = 0);
    let f = forth();
    let outputs = f.evaluate(r#"0 0.25 0.5 0.75 at sine snd [ c4 e4 ] cycle note ."#, &ctx).unwrap();
    assert_eq!(outputs.len(), 4);
    let notes = get_notes(&outputs);
    assert!(approx_eq(notes[0], 60.0)); // idx 0 % 2 = 0 -> c4
    assert!(approx_eq(notes[1], 64.0)); // idx 1 % 2 = 1 -> e4
    assert!(approx_eq(notes[2], 60.0)); // idx 2 % 2 = 0 -> c4
    assert!(approx_eq(notes[3], 64.0)); // idx 3 % 2 = 1 -> e4
}

#[test]
fn at_loop_rand_different_per_subdivision() {
    // rand inside at-loop produces different values per iteration
    let f = forth();
    let outputs = f.evaluate(r#"0 0.5 at sine snd 1 1000 rand freq ."#, &default_ctx()).unwrap();
    assert_eq!(outputs.len(), 2);
    let freqs: Vec<f64> = outputs.iter()
        .map(|o| parse_params(o).get("freq").copied().unwrap_or(0.0))
        .collect();
    assert!(freqs[0] != freqs[1], "rand should produce different values: {} vs {}", freqs[0], freqs[1]);
}

#[test]
fn at_loop_poly_cycling() {
    // CycleList inside at-loop: poly stacking within each iteration
    let outputs = expect_outputs(r#"0 0.5 at sine snd c4 e4 note ."#, 4);
    let notes = get_notes(&outputs);
    // Each iteration emits both poly voices (c4 and e4)
    assert!(approx_eq(notes[0], 60.0));  // iter 0, poly 0
    assert!(approx_eq(notes[1], 64.0));  // iter 0, poly 1
    assert!(approx_eq(notes[2], 60.0));  // iter 1, poly 0
    assert!(approx_eq(notes[3], 64.0));  // iter 1, poly 1
}

// --- every+ / except+ tests ---

#[test]
fn every_offset_fires_at_offset() {
    for iter in 0..8 {
        let ctx = ctx_with(|c| c.iter = iter);
        let f = forth();
        let outputs = f.evaluate(r#""kick" snd ( . ) 4 2 every+"#, &ctx).unwrap();
        if iter % 4 == 2 {
            assert_eq!(outputs.len(), 1, "iter={}: should fire", iter);
        } else {
            assert_eq!(outputs.len(), 0, "iter={}: should not fire", iter);
        }
    }
}

#[test]
fn every_offset_wraps_large_offset() {
    // offset 6 with n=4 → 6 % 4 = 2, same as offset 2
    for iter in 0..8 {
        let ctx = ctx_with(|c| c.iter = iter);
        let f = forth();
        let outputs = f.evaluate(r#""kick" snd ( . ) 4 6 every+"#, &ctx).unwrap();
        if iter % 4 == 2 {
            assert_eq!(outputs.len(), 1, "iter={}: should fire (wrapped offset)", iter);
        } else {
            assert_eq!(outputs.len(), 0, "iter={}: should not fire", iter);
        }
    }
}

#[test]
fn except_offset_inverse() {
    for iter in 0..8 {
        let ctx = ctx_with(|c| c.iter = iter);
        let f = forth();
        let outputs = f.evaluate(r#""kick" snd ( . ) 4 2 except+"#, &ctx).unwrap();
        if iter % 4 != 2 {
            assert_eq!(outputs.len(), 1, "iter={}: should fire", iter);
        } else {
            assert_eq!(outputs.len(), 0, "iter={}: should not fire", iter);
        }
    }
}

#[test]
fn every_offset_zero_is_same_as_every() {
    for iter in 0..8 {
        let ctx = ctx_with(|c| c.iter = iter);
        let f = forth();
        let a = f.evaluate(r#""kick" snd ( . ) 3 every"#, &ctx).unwrap();
        let b = f.evaluate(r#""kick" snd ( . ) 3 0 every+"#, &ctx).unwrap();
        assert_eq!(a.len(), b.len(), "iter={}: every and every+ 0 should match", iter);
    }
}

// --- at-loop feature tests ---

#[test]
fn at_loop_choose_independent_per_subdivision() {
    let f = forth();
    let outputs = f.evaluate(r#"0 0.5 at sine snd [ 60 64 67 71 ] choose note ."#, &default_ctx()).unwrap();
    assert_eq!(outputs.len(), 2);
    // Both are valid notes from the set (just verify they're within range)
    let notes = get_notes(&outputs);
    for n in &notes {
        assert!([60.0, 64.0, 67.0, 71.0].contains(n), "unexpected note {n}");
    }
}

#[test]
fn at_loop_multiple_blocks_independent() {
    let outputs = expect_outputs(
        r#"0 0.5 at "kick" snd . 0 0.25 0.5 at "hat" snd ."#,
        5,
    );
    let sounds = get_sounds(&outputs);
    assert_eq!(sounds[0], "kick");
    assert_eq!(sounds[1], "kick");
    assert_eq!(sounds[2], "hat");
    assert_eq!(sounds[3], "hat");
    assert_eq!(sounds[4], "hat");
}

#[test]
fn at_loop_single_delta_one_iteration() {
    let outputs = expect_outputs(r#"0.25 at "kick" snd ."#, 1);
    let sounds = get_sounds(&outputs);
    assert_eq!(sounds[0], "kick");
    let deltas = get_deltas(&outputs);
    let step_dur = 0.125;
    let sr: f64 = 48000.0;
    assert!(approx_eq(deltas[0], (0.25 * step_dur * sr).round()));
}

#[test]
fn at_without_closer_falls_back_to_legacy() {
    // When at has no matching closer (., m., done), falls back to Op::At
    let f = forth();
    let result = f.evaluate(r#"0 0.5 at "kick" snd"#, &default_ctx());
    assert!(result.is_ok());
}

#[test]
fn at_loop_cycle_advances_across_runs() {
    // Across different runs values, cycle inside at-loop picks correctly
    for base_runs in 0..3 {
        let ctx = ctx_with(|c| c.runs = base_runs);
        let f = forth();
        let outputs = f.evaluate(
            r#"0 0.5 at sine snd [ c4 e4 g4 ] cycle note ."#,
            &ctx,
        ).unwrap();
        assert_eq!(outputs.len(), 2);
        let notes = get_notes(&outputs);
        // runs for iter i = base_runs * 2 + i
        let expected_0 = [60.0, 64.0, 67.0][(base_runs * 2) % 3];
        let expected_1 = [60.0, 64.0, 67.0][(base_runs * 2 + 1) % 3];
        assert!(approx_eq(notes[0], expected_0), "runs={base_runs}: iter 0 expected {expected_0}, got {}", notes[0]);
        assert!(approx_eq(notes[1], expected_1), "runs={base_runs}: iter 1 expected {expected_1}, got {}", notes[1]);
    }
}

#[test]
fn at_loop_midi_emit() {
    let f = forth();
    let outputs = f.evaluate("0 0.25 0.5 at 60 note m.", &default_ctx()).unwrap();
    assert_eq!(outputs.len(), 3);
    for o in &outputs {
        assert!(o.contains("/midi/note/60/"));
    }
    // First should have no delta (or delta/0), others should have delta
    assert!(outputs[1].contains("/delta/"));
    assert!(outputs[2].contains("/delta/"));
}

#[test]
fn at_loop_done_no_emit() {
    let f = forth();
    let outputs = f.evaluate("0 0.5 at [ 1 2 ] cycle drop done", &default_ctx()).unwrap();
    assert!(outputs.is_empty());
}

#[test]
fn at_loop_done_sets_variables() {
    let f = forth();
    let outputs = f
        .evaluate("0 0.5 at [ 10 20 ] cycle !x done kick snd @x freq .", &default_ctx())
        .unwrap();
    assert_eq!(outputs.len(), 1);
    // Last iteration wins: cycle(1) = 20
    let params = parse_params(&outputs[0]);
    assert!(approx_eq(*params.get("freq").unwrap(), 20.0));
}