use mem_store::{ObsidianProjector, ProjectorOpts, MemoryRecord, MemoryParent};
use std::collections::HashMap;
use std::fs;
use std::path::PathBuf;
use tempfile::TempDir;

/// Test fixture: Create L1 memory
fn make_l1(
    project: &str,
    query_id: &str,
    text: &str,
    run_id: &str,
    chunks_seen: i32,
    chunks_used: i32,
    parents: Vec<MemoryParent>,
) -> MemoryRecord {
    MemoryRecord {
        level: "L1".to_string(),
        project: project.to_string(),
        query_id: Some(query_id.to_string()),
        text: text.to_string(),
        updated: "2025-01-27T12:00:00Z".to_string(),
        run_id: run_id.to_string(),
        t: 0,
        source: None,
        chunks_seen: Some(chunks_seen),
        chunks_used: Some(chunks_used),
        parents,
    }
}

/// Test fixture: Create L2 memory
fn make_l2(project: &str, text: &str, run_id: &str) -> MemoryRecord {
    MemoryRecord {
        level: "L2".to_string(),
        project: project.to_string(),
        query_id: None,
        text: text.to_string(),
        updated: "2025-01-27T12:00:00Z".to_string(),
        run_id: run_id.to_string(),
        t: 1,
        source: None,
        chunks_seen: None,
        chunks_used: None,
        parents: vec![],
    }
}

/// Test fixture: Create L0 memory
fn make_l0(project: &str, source: &str, t: i32, text: &str) -> MemoryRecord {
    MemoryRecord {
        level: "L0".to_string(),
        project: project.to_string(),
        query_id: None,
        text: text.to_string(),
        updated: "2025-01-27T12:00:00Z".to_string(),
        run_id: "r1".to_string(),
        t,
        source: Some(source.to_string()),
        chunks_seen: None,
        chunks_used: None,
        parents: vec![],
    }
}

#[tokio::test]
async fn a1_byte_identical_twice() {
    let tmp = TempDir::new().expect("tempdir");
    let vault1 = tmp.path().join("vault1");
    let vault2 = tmp.path().join("vault2");

    let l1 = make_l1("test", "q1", "Memory text", "r1", 10, 5, vec![]);
    let l2 = make_l2("test", "Synthesis", "r1");

    // Project twice into different directories
    let mut l1_by_query = HashMap::new();
    l1_by_query.insert("q1".to_string(), l1.clone());

    let content1 = ObsidianProjector::render_l1(&l1).expect("render 1");
    let content2 = ObsidianProjector::render_l1(&l1).expect("render 2");

    assert_eq!(
        content1, content2,
        "Multiple renders of same input should be byte-identical"
    );
}

#[tokio::test]
async fn a2_no_generation_timestamp() {
    let l1 = make_l1("test", "q1", "Memory", "r1", 10, 5, vec![]);
    
    let content1 = ObsidianProjector::render_l1(&l1).expect("render 1");
    
    // Simulate time passage
    tokio::time::sleep(tokio::time::Duration::from_millis(100)).await;
    
    let content2 = ObsidianProjector::render_l1(&l1).expect("render 2");

    assert_eq!(
        content1, content2,
        "Content should be identical even after time passes (no now() in output)"
    );
}

#[test]
fn a3_frontmatter_key_order() {
    let l1 = make_l1("test", "q1", "Memory", "r1", 10, 5, vec![]);
    let content = ObsidianProjector::render_l1(&l1).expect("render");

    let lines: Vec<&str> = content.lines().collect();
    let fm_end = lines
        .iter()
        .position(|line| line == &"---")
        .expect("closing ---");
    
    let fm_lines = &lines[1..fm_end];

    // Keys should be in alphabetical order (BTreeMap)
    let mut prev = "";
    for line in fm_lines {
        let key = line.split(':').next().unwrap_or("");
        if !prev.is_empty() {
            assert!(
                key >= prev,
                "Keys not sorted: {} should be >= {}",
                key,
                prev
            );
        }
        prev = key;
    }
}

#[test]
fn a4_golden_structure() {
    let l1 = make_l1("test", "query-a", "This is the memory", "r1", 100, 50, vec![
        MemoryParent {
            source: "pi".to_string(),
            t: 1,
            description: Some("chunk 1 — first note".to_string()),
        },
        MemoryParent {
            source: "claude".to_string(),
            t: 2,
            description: Some("chunk 2 — second note".to_string()),
        },
    ]);

    let content = ObsidianProjector::render_l1(&l1).expect("render");

    // Check structure
    assert!(content.starts_with("---"));
    assert!(content.contains("project: test"));
    assert!(content.contains("level: L1"));
    assert!(content.contains("query_id: query-a"));
    assert!(content.contains("updated: 2025-01-27T12:00:00Z"));
    assert!(content.contains("run_id: r1"));
    assert!(content.contains("chunks_seen: 100"));
    assert!(content.contains("chunks_used: 50"));
    assert!(content.contains("# query-a — test"));
    assert!(content.contains("This is the memory"));
    assert!(content.contains("## Provenance"));
    assert!(content.contains("- [[claude-2]] — chunk 2 — second note"));
    assert!(content.contains("- [[pi-1]] — chunk 1 — first note"));
    assert!(content.contains("[[index]]"));
}

#[test]
fn a5_empty_memory_still_writes() {
    let l1 = make_l1("test", "q1", "", "r1", 0, 0, vec![]);
    let content = ObsidianProjector::render_l1(&l1).expect("render");

    assert!(content.contains("_No evidence found for this query._"));
    assert!(content.contains("[[index]]"));
}

#[test]
fn a6_links_bidirectional() {
    let mut l1_by_query = HashMap::new();
    l1_by_query.insert(
        "query-a".to_string(),
        make_l1("test", "query-a", "Memory A", "r1", 10, 5, vec![]),
    );
    l1_by_query.insert(
        "query-b".to_string(),
        make_l1("test", "query-b", "Memory B", "r1", 20, 10, vec![]),
    );

    let l2 = make_l2("test", "Synthesis", "r1");
    let l2_content = ObsidianProjector::render_l2(&l2, &l1_by_query).expect("render L2");

    // L2 should link to both L1 notes
    assert!(l2_content.contains("[[query-a]]"));
    assert!(l2_content.contains("[[query-b]]"));

    // Each L1 should link back to L2
    for (_, l1) in l1_by_query.iter() {
        let l1_content = ObsidianProjector::render_l1(l1).expect("render L1");
        assert!(l1_content.contains("[[index]]"));
    }
}

#[test]
fn a7_evidence_notes_rendering() {
    let l0 = make_l0("test", "pi", 1, "Raw chunk from pi");
    let content = ObsidianProjector::render_l0(&l0).expect("render");

    // Check structure
    assert!(content.starts_with("---"));
    assert!(content.contains("project: test"));
    assert!(content.contains("level: L0"));
    assert!(content.contains("source: pi"));
    assert!(content.contains("# pi — test"));
    assert!(content.contains("Raw chunk from pi"));
}

#[test]
fn a8_line_endings_and_newline() {
    let l1 = make_l1("test", "q1", "Line 1\nLine 2", "r1", 10, 5, vec![]);
    let content = ObsidianProjector::render_l1(&l1).expect("render");

    // No \r\n (Windows line endings)
    assert!(!content.contains("\r\n"), "Content should not have Windows line endings");

    // Exactly one trailing newline
    assert!(
        content.ends_with("\n"),
        "Content should end with exactly one newline"
    );
    assert!(
        !content.ends_with("\n\n"),
        "Content should not end with double newline"
    );

    // No trailing whitespace on lines
    for line in content.lines() {
        assert_eq!(
            line,
            line.trim_end(),
            "Line should not have trailing whitespace: '{}'",
            line
        );
    }
}

#[test]
fn a9_provenance_sorted_by_source_then_t() {
    let parents = vec![
        MemoryParent {
            source: "claude".to_string(),
            t: 3,
            description: None,
        },
        MemoryParent {
            source: "pi".to_string(),
            t: 1,
            description: None,
        },
        MemoryParent {
            source: "claude".to_string(),
            t: 1,
            description: None,
        },
        MemoryParent {
            source: "pi".to_string(),
            t: 2,
            description: None,
        },
    ];

    let l1 = MemoryRecord {
        level: "L1".to_string(),
        project: "test".to_string(),
        query_id: Some("q1".to_string()),
        text: "Memory".to_string(),
        updated: "2025-01-27T12:00:00Z".to_string(),
        run_id: "r1".to_string(),
        t: 0,
        source: None,
        chunks_seen: None,
        chunks_used: None,
        parents,
    };

    let content = ObsidianProjector::render_l1(&l1).expect("render");
    let provenance_section = content.split("## Provenance").nth(1).unwrap();
    let lines: Vec<&str> = provenance_section.lines().collect();

    // Should be sorted: claude-1, claude-3, pi-1, pi-2
    assert!(lines[1].contains("claude-1"));
    assert!(lines[2].contains("claude-3"));
    assert!(lines[3].contains("pi-1"));
    assert!(lines[4].contains("pi-2"));
}

#[test]
fn a10_no_trailing_whitespace() {
    let l1 = make_l1("test", "q1", "Line with text  ", "r1", 10, 5, vec![]);
    let content = ObsidianProjector::render_l1(&l1).expect("render");

    for line in content.lines() {
        let trimmed = line.trim_end();
        assert_eq!(
            line, trimmed,
            "Line '{}' has trailing whitespace",
            line
        );
    }
}