//! LSP-side workspace plumbing:
//! - `WorkspaceEditBuilder` (changes-map vs document-changes promotion)
//!   and `TextEdit` UTF-8/UTF-16 conversion.
//! - `Config` desugar from `initializationOptions` JSON (per-wiki keys,
//!   legacy single-wiki shape).
//! - `Wiki` resolution: building wikis from raw config and matching
//!   URIs to the longest-prefix wiki root.
//! - `collect_diagnostics` composition (parser errors + link-health).

use std::path::PathBuf;

use nuwiki_core::ast::{
    inline::InlineNode, BlockNode, DocumentNode, ErrorNode, ParagraphNode, Position as AstPosition,
    Span, TextNode,
};
use nuwiki_lsp::collect_diagnostics;
use nuwiki_lsp::config::{config_from_json, Config, DiagnosticConfig, LinkSeverity, WikiConfig};
use nuwiki_lsp::edits::{
    op_create, op_delete, op_rename, text_edit_delete, text_edit_insert, text_edit_replace,
    WorkspaceEditBuilder,
};
use nuwiki_lsp::wiki::{build_wikis, resolve_uri_to_wiki, Wiki, WikiId};
use serde_json::json;
use tower_lsp::lsp_types::{DocumentChanges, Position as LspPosition, Url};

// ===== Edits =====

fn span_one_line(byte_col: u32, len: u32) -> Span {
    Span::new(
        AstPosition {
            line: 0,
            column: byte_col,
            offset: byte_col as usize,
        },
        AstPosition {
            line: 0,
            column: byte_col + len,
            offset: (byte_col + len) as usize,
        },
    )
}

#[test]
fn text_edit_replace_passthrough_in_utf8() {
    let edit = text_edit_replace(span_one_line(0, 5), "world".into(), "hello there", true);
    assert_eq!(edit.range.start.character, 0);
    assert_eq!(edit.range.end.character, 5);
    assert_eq!(edit.new_text, "world");
}

#[test]
fn text_edit_replace_converts_to_utf16_for_multibyte() {
    // "héllo" — h(1B) é(2B) l(1B) l(1B) o(1B); UTF-16 chars: 1+1+1+1+1=5.
    // span covers bytes 0..3 (h + é); UTF-16 character count = 2.
    let edit = text_edit_replace(span_one_line(0, 3), "X".into(), "héllo", false);
    assert_eq!(edit.range.start.character, 0);
    assert_eq!(edit.range.end.character, 2);
}

#[test]
fn text_edit_insert_produces_zero_width_range() {
    let edit = text_edit_insert(
        LspPosition {
            line: 0,
            character: 4,
        },
        "X".into(),
    );
    assert_eq!(edit.range.start, edit.range.end);
    assert_eq!(edit.new_text, "X");
}

#[test]
fn text_edit_delete_has_empty_new_text() {
    let edit = text_edit_delete(span_one_line(0, 3), "abcdef", true);
    assert_eq!(edit.new_text, "");
    assert_eq!(edit.range.end.character, 3);
}

#[test]
fn builder_with_only_edits_uses_changes_map() {
    let uri = Url::parse("file:///tmp/a.wiki").unwrap();
    let mut b = WorkspaceEditBuilder::new();
    b.edit(
        uri.clone(),
        text_edit_replace(span_one_line(0, 3), "new".into(), "old text", true),
    );
    let we = b.build();
    assert!(we.changes.is_some());
    assert!(we.document_changes.is_none());
    let changes = we.changes.unwrap();
    assert_eq!(changes.len(), 1);
    assert_eq!(changes[&uri].len(), 1);
}

#[test]
fn builder_with_file_op_promotes_to_document_changes() {
    let old = Url::parse("file:///tmp/A.wiki").unwrap();
    let new = Url::parse("file:///tmp/B.wiki").unwrap();
    let mut b = WorkspaceEditBuilder::new();
    b.file_op(op_rename(old.clone(), new.clone()));
    b.edit(
        new.clone(),
        text_edit_replace(span_one_line(0, 1), "X".into(), "Y", true),
    );
    let we = b.build();
    assert!(we.changes.is_none());
    let DocumentChanges::Operations(ops) = we.document_changes.unwrap() else {
        panic!("expected Operations variant");
    };
    // Rename comes first (file ops always precede content edits in the
    // builder), then the text edit on the renamed file.
    assert_eq!(ops.len(), 2);
}

#[test]
fn builder_is_empty_until_something_pushed() {
    let mut b = WorkspaceEditBuilder::new();
    assert!(b.is_empty());
    b.file_op(op_delete(Url::parse("file:///x").unwrap()));
    assert!(!b.is_empty());
}

#[test]
fn op_create_round_trips_through_builder() {
    let uri = Url::parse("file:///tmp/new.wiki").unwrap();
    let mut b = WorkspaceEditBuilder::new();
    b.file_op(op_create(uri));
    let we = b.build();
    assert!(we.document_changes.is_some());
}

// ===== Config =====

#[test]
fn config_default_is_empty() {
    let c = Config::default();
    assert!(c.wikis.is_empty());
    assert_eq!(c.diagnostic.link_severity, LinkSeverity::Warning);
}

#[test]
fn v1_0_single_wiki_desugars_to_one_entry() {
    let cfg = config_from_json(json!({
        "wiki_root": "/tmp/vimwiki",
        "file_extension": ".wiki",
        "syntax": "vimwiki",
    }));
    assert_eq!(cfg.wikis.len(), 1);
    assert_eq!(cfg.wikis[0].root, PathBuf::from("/tmp/vimwiki"));
    assert_eq!(cfg.wikis[0].file_extension, ".wiki");
    assert_eq!(cfg.wikis[0].syntax, "vimwiki");
}

#[test]
fn explicit_wikis_list_overrides_legacy_shape() {
    let cfg = config_from_json(json!({
        "wiki_root": "/tmp/IGNORED",
        "wikis": [
            { "root": "/tmp/personal", "name": "personal" },
            { "root": "/tmp/work", "syntax": "vimwiki" },
        ],
    }));
    assert_eq!(cfg.wikis.len(), 2);
    assert_eq!(cfg.wikis[0].name, "personal");
    assert_eq!(cfg.wikis[1].root, PathBuf::from("/tmp/work"));
}

#[test]
fn empty_json_yields_no_wikis() {
    let cfg = config_from_json(json!({}));
    assert!(cfg.wikis.is_empty());
}

#[test]
fn invalid_json_leaves_existing_config_unchanged() {
    let mut cfg = Config::default();
    cfg.wikis
        .push(WikiConfig::from_root(PathBuf::from("/tmp/a")));
    cfg.apply_change(&json!("not a config object"));
    // Existing wikis still present.
    assert_eq!(cfg.wikis.len(), 1);
}

// ===== Wiki aggregate =====

fn wiki_at(id: u32, root: &str) -> Wiki {
    Wiki::new(WikiId(id), WikiConfig::from_root(PathBuf::from(root)))
}

#[test]
fn build_wikis_assigns_sequential_ids() {
    let configs = vec![
        WikiConfig::from_root(PathBuf::from("/tmp/a")),
        WikiConfig::from_root(PathBuf::from("/tmp/b")),
    ];
    let wikis = build_wikis(&configs);
    assert_eq!(wikis.len(), 2);
    assert_eq!(wikis[0].id, WikiId(0));
    assert_eq!(wikis[1].id, WikiId(1));
}

#[test]
fn resolve_uri_to_wiki_picks_longest_prefix() {
    let wikis = vec![wiki_at(0, "/wiki"), wiki_at(1, "/wiki/sub")];
    let uri = Url::from_file_path("/wiki/sub/page.wiki").unwrap();
    assert_eq!(resolve_uri_to_wiki(&wikis, &uri), Some(WikiId(1)));
}

#[test]
fn resolve_uri_to_wiki_misses_outside_any_root() {
    let wikis = vec![wiki_at(0, "/wiki")];
    let uri = Url::from_file_path("/other/page.wiki").unwrap();
    assert!(resolve_uri_to_wiki(&wikis, &uri).is_none());
}

#[test]
fn wiki_contains_respects_root_prefix() {
    let w = wiki_at(0, "/wiki");
    assert!(w.contains(&Url::from_file_path("/wiki/note.wiki").unwrap()));
    assert!(!w.contains(&Url::from_file_path("/other/note.wiki").unwrap()));
}

// ===== Diagnostics composition =====

#[test]
fn collect_diagnostics_emits_one_per_error_node() {
    let doc = DocumentNode {
        span: Span::default(),
        metadata: Default::default(),
        children: vec![
            BlockNode::Error(ErrorNode {
                span: span_one_line(0, 3),
                raw: "oops".into(),
                message: "broken".into(),
            }),
            BlockNode::Paragraph(ParagraphNode {
                span: Span::default(),
                children: vec![InlineNode::Text(TextNode {
                    span: Span::default(),
                    content: "ok".into(),
                })],
            }),
        ],
    };
    let cfg = DiagnosticConfig::default();
    let diags = collect_diagnostics(&doc, "abc ok", None, None, None, &cfg, true);
    assert_eq!(diags.len(), 1);
    assert_eq!(diags[0].message, "broken");
}

#[test]
fn collect_diagnostics_link_health_emits_nothing_without_index() {
    // No index → link-health source is skipped, even when severity is on.
    let doc = DocumentNode::default();
    let cfg = DiagnosticConfig {
        link_severity: LinkSeverity::Error,
    };
    let diags = collect_diagnostics(&doc, "", None, None, Some("Home"), &cfg, true);
    assert!(diags.is_empty());
}

// ===== Per-wiki config defaults + JSON parsing =====

#[test]
fn defaults_carry_vimwiki_per_wiki_keys() {
    let cfg = WikiConfig::empty();
    assert_eq!(cfg.index, "index");
    assert_eq!(cfg.diary_frequency, "daily");
    assert_eq!(cfg.diary_caption_level, 0); // upstream default
    assert_eq!(cfg.diary_sort, "desc");
    assert_eq!(cfg.diary_header, "Diary");
    assert_eq!(cfg.listsyms, " .oOX");
    assert!(cfg.listsyms_propagate);
    assert_eq!(cfg.list_margin, -1);
    assert_eq!(cfg.links_space_char, " ");
    assert!(!cfg.auto_toc);
    assert!(!cfg.auto_generate_links);
    assert!(!cfg.auto_generate_tags);
    assert!(!cfg.auto_diary_index);
    // Generated-section captions match upstream defaults.
    assert_eq!(cfg.toc_header, "Contents");
    assert_eq!(cfg.toc_header_level, 1);
    assert_eq!(cfg.links_header, "Generated Links");
    assert_eq!(cfg.tags_header, "Generated Tags");
    assert_eq!(cfg.listsym_rejected, "-");
    // No external converter / public base URL by default.
    assert_eq!(cfg.html.custom_wiki2html, "");
    assert_eq!(cfg.html.custom_wiki2html_args, "");
    assert_eq!(cfg.html.base_url, "");
}

#[test]
fn raw_wiki_parses_every_new_key() {
    let cfg = config_from_json(serde_json::json!({
        "wikis": [{
            "root": "/tmp/w",
            "index": "home",
            "diary_frequency": "weekly",
            "diary_weekly_style": "date",
            "diary_start_week_day": "sunday",
            "diary_caption_level": 2,
            "diary_sort": "asc",
            "diary_header": "Journal",
            "listsyms": "abcde",
            "listsym_rejected": "✗",
            "listsyms_propagate": false,
            "list_margin": 2,
            "links_space_char": "_",
            "auto_toc": true,
            "auto_generate_links": true,
            "auto_generate_tags": 1,
            "auto_diary_index": true,
            "toc_header": "Table of Contents",
            "toc_header_level": 2,
            "links_header": "All Pages",
            "tags_header": "Tag Index",
            "tags_header_level": 3,
            "custom_wiki2html": "~/bin/my_wiki2html.sh",
            "custom_wiki2html_args": "--flag",
            "base_url": "https://example.com/wiki/",
        }],
    }));
    let w = &cfg.wikis[0];
    assert_eq!(w.index, "home");
    assert_eq!(w.diary_frequency, "weekly");
    assert_eq!(w.diary_weekly_style, "date");
    assert_eq!(w.diary_start_week_day, "sunday");
    assert_eq!(w.diary_caption_level, 2);
    assert_eq!(w.diary_sort, "asc");
    assert_eq!(w.diary_header, "Journal");
    assert_eq!(w.listsyms, "abcde");
    assert_eq!(w.listsym_rejected, "✗");
    assert_eq!(w.list_syms().rejected_glyph(), '✗');
    assert!(!w.listsyms_propagate);
    assert_eq!(w.list_margin, 2);
    assert_eq!(w.links_space_char, "_");
    assert!(w.auto_toc);
    assert!(w.auto_generate_links);
    assert!(w.auto_generate_tags); // int 1 → true
    assert!(w.auto_diary_index);
    assert_eq!(w.toc_header, "Table of Contents");
    assert_eq!(w.toc_header_level, 2);
    assert_eq!(w.links_header, "All Pages");
    assert_eq!(w.links_header_level, 1); // unspecified → default
    assert_eq!(w.tags_header, "Tag Index");
    assert_eq!(w.tags_header_level, 3);
    // custom_wiki2html keeps the literal command string (tilde-expansion is
    // the converter's job, not ours); args + base_url round-trip verbatim.
    assert_eq!(w.html.custom_wiki2html, "~/bin/my_wiki2html.sh");
    assert_eq!(w.html.custom_wiki2html_args, "--flag");
    assert_eq!(w.html.base_url, "https://example.com/wiki/");

    // The parsed keys drive a date-mode, Sunday-start diary calendar:
    // a weekly note is the week-start date (YYYY-MM-DD), stepping ±7 days.
    use nuwiki_core::date::{DiaryDate, DiaryPeriod};
    let cal = w.diary_calendar();
    let wed = DiaryPeriod::Day(DiaryDate::from_ymd(2026, 5, 27).unwrap());
    assert_eq!(
        cal.next(wed),
        DiaryPeriod::Day(DiaryDate::from_ymd(2026, 5, 31).unwrap())
    );
}

#[test]
fn diary_calendar_defaults_to_iso_weeks() {
    let cfg = WikiConfig::empty();
    assert_eq!(cfg.diary_weekly_style, "iso");
    assert_eq!(cfg.diary_start_week_day, "monday");
}

#[test]
fn link_severity_parses_from_client_config() {
    for (input, expected) in [
        ("off", LinkSeverity::Off),
        ("hint", LinkSeverity::Hint),
        ("warn", LinkSeverity::Warning),
        ("warning", LinkSeverity::Warning),
        ("error", LinkSeverity::Error),
        ("ERROR", LinkSeverity::Error),
    ] {
        let cfg = config_from_json(json!({
            "wiki_root": "/tmp/w",
            "diagnostic": { "link_severity": input },
        }));
        assert_eq!(
            cfg.diagnostic.link_severity, expected,
            "input {input:?} should map to {expected:?}"
        );
    }
}

#[test]
fn link_severity_invalid_or_absent_falls_back_to_default() {
    // Unknown string → default (Warning).
    let bad = config_from_json(json!({
        "wiki_root": "/tmp/w",
        "diagnostic": { "link_severity": "loud" },
    }));
    assert_eq!(bad.diagnostic.link_severity, LinkSeverity::Warning);

    // No diagnostic key at all → default.
    let none = config_from_json(json!({ "wiki_root": "/tmp/w" }));
    assert_eq!(none.diagnostic.link_severity, LinkSeverity::Warning);
}

#[test]
fn apply_change_preserves_severity_on_partial_update() {
    let mut cfg = config_from_json(json!({
        "wiki_root": "/tmp/w",
        "diagnostic": { "link_severity": "error" },
    }));
    assert_eq!(cfg.diagnostic.link_severity, LinkSeverity::Error);

    // A later update that omits `diagnostic` must not reset severity.
    cfg.apply_change(&json!({ "wiki_root": "/tmp/w2" }));
    assert_eq!(cfg.diagnostic.link_severity, LinkSeverity::Error);
}

#[test]
fn apply_change_minimal_diagnostic_payload_is_not_unwrapped() {
    // A lone `{ "diagnostic": { … } }` is a real flat payload, not a
    // `{ "nuwiki": { … } }` namespace wrapper. The single-key unwrap must
    // skip it (it's a recognised top-level key) so the severity applies.
    let mut cfg = config_from_json(json!({ "wiki_root": "/tmp/w" }));
    assert_eq!(cfg.diagnostic.link_severity, LinkSeverity::Warning);

    cfg.apply_change(&json!({ "diagnostic": { "link_severity": "error" } }));
    assert_eq!(cfg.diagnostic.link_severity, LinkSeverity::Error);

    // The Neovim namespace wrapper still unwraps correctly.
    cfg.apply_change(&json!({ "nuwiki": { "diagnostic": { "link_severity": "hint" } } }));
    assert_eq!(cfg.diagnostic.link_severity, LinkSeverity::Hint);
}

#[test]
fn severity_change_via_apply_change_is_observable_in_collected_diagnostics() {
    // Contract behind `did_change_configuration`'s diagnostic re-publish:
    // once `apply_change` updates the severity, re-running `collect_diagnostics`
    // (what the handler does for every open doc) must emit broken-link
    // diagnostics at the *new* severity. Guards the data path the handler
    // depends on — apply_change writing the severity AND collect_diagnostics
    // reading it.
    use nuwiki_core::syntax::vimwiki::VimwikiSyntax;
    use nuwiki_core::syntax::SyntaxPlugin;
    use nuwiki_lsp::index::WorkspaceIndex;
    use tower_lsp::lsp_types::DiagnosticSeverity;

    let root = "/tmp/cfgchange";
    let src = "[[GhostPage]]\n";
    let ast = VimwikiSyntax::new().parse(src);
    let mut idx = WorkspaceIndex::new(Some(PathBuf::from(root)));
    let uri = Url::from_file_path(format!("{root}/Home.wiki")).unwrap();
    idx.upsert(uri.clone(), &ast);

    let mut cfg = config_from_json(json!({
        "wiki_root": root,
        "diagnostic": { "link_severity": "warn" },
    }));
    let warn = collect_diagnostics(
        &ast,
        src,
        Some(&uri),
        Some(&idx),
        Some("Home"),
        &cfg.diagnostic,
        true,
    );
    assert_eq!(warn.len(), 1, "broken link should warn");
    assert_eq!(warn[0].severity, Some(DiagnosticSeverity::WARNING));

    // Simulate the client raising severity via didChangeConfiguration.
    cfg.apply_change(&json!({ "diagnostic": { "link_severity": "error" } }));
    let err = collect_diagnostics(
        &ast,
        src,
        Some(&uri),
        Some(&idx),
        Some("Home"),
        &cfg.diagnostic,
        true,
    );
    assert_eq!(err.len(), 1);
    assert_eq!(
        err[0].severity,
        Some(DiagnosticSeverity::ERROR),
        "re-collected diagnostics must reflect the new severity"
    );
}

#[test]
fn vim_flat_and_neovim_wrapped_payloads_desugar_identically() {
    // Parity guard for the two client shapes:
    //   * Vim   (`autoload/nuwiki/lsp.vim`)  → flat init_options dict.
    //   * Neovim (`lua/nuwiki/lsp.lua`)       → `{ nuwiki = { … } }` for
    //     `workspace/didChangeConfiguration` (server_settings()).
    // Both must produce the same wikis; otherwise switching editors would
    // silently change how the server resolves links/diary/HTML paths.
    let inner = json!({
        "wiki_root": "/tmp/base",
        "file_extension": ".md",
        "syntax": "vimwiki",
        "log_level": "debug",
        "diagnostic": { "link_severity": "error" },
        "wikis": [
            {
                "name": "personal",
                "root": "/tmp/personal",
                "file_extension": ".wiki",
                "index": "home",
                "diary_rel_path": "journal",
            },
            { "name": "work", "root": "/tmp/work" },
        ],
    });

    let flat = config_from_json(inner.clone());
    let wrapped = config_from_json(json!({ "nuwiki": inner }));

    assert_eq!(
        flat.diagnostic.link_severity,
        wrapped.diagnostic.link_severity
    );
    assert_eq!(flat.diagnostic.link_severity, LinkSeverity::Error);
    assert_eq!(flat.wikis.len(), wrapped.wikis.len());
    for (a, b) in flat.wikis.iter().zip(wrapped.wikis.iter()) {
        assert_eq!(a.name, b.name);
        assert_eq!(a.root, b.root);
        assert_eq!(a.file_extension, b.file_extension);
        assert_eq!(a.syntax, b.syntax);
        assert_eq!(a.index, b.index);
        assert_eq!(a.diary_rel_path, b.diary_rel_path);
    }

    // And the desugared list matches the per-wiki values both clients send.
    assert_eq!(flat.wikis[0].name, "personal");
    assert_eq!(flat.wikis[0].root, PathBuf::from("/tmp/personal"));
    assert_eq!(flat.wikis[0].file_extension, ".wiki");
    assert_eq!(flat.wikis[0].index, "home");
    assert_eq!(flat.wikis[0].diary_rel_path, "journal");
    assert_eq!(flat.wikis[1].name, "work");
    assert_eq!(flat.wikis[1].root, PathBuf::from("/tmp/work"));
}

#[test]
fn legacy_single_wiki_shape_picks_up_defaults() {
    let cfg = config_from_json(serde_json::json!({
        "wiki_root": "/tmp/legacy",
    }));
    assert_eq!(cfg.wikis.len(), 1);
    assert_eq!(cfg.wikis[0].index, "index");
    assert_eq!(cfg.wikis[0].diary_frequency, "daily");
}