//! Table Keyboard Handling
//!
//! Handles keyboard navigation, editing, and incremental search.
//! Part of the table widget module.

const Context = @import("../../core/context.zig").Context;

const types = @import("types.zig");
const state_mod = @import("state.zig");

const TableState = state_mod.TableState;
const TableResult = state_mod.TableResult;
const TableConfig = types.TableConfig;
const CellDataFn = types.CellDataFn;
const CellEditFn = types.CellEditFn;
const CellValidateFn = types.CellValidateFn;

/// Handle keyboard input for table navigation and editing
pub fn handleKeyboard(
    ctx: *Context,
    state: *TableState,
    col_count: usize,
    visible_rows: usize,
    get_cell: CellDataFn,
    on_edit: ?CellEditFn,
    validate: ?CellValidateFn,
    config: TableConfig,
    result: *TableResult,
) void {
    // Check for navigation keys
    if (ctx.input.navKeyPressed()) |key| {
        switch (key) {
            .up => {
                if (state.selected_row > 0) {
                    state.selected_row -= 1;
                    result.selection_changed = true;
                    state.ensureVisible(visible_rows);
                }
            },
            .down => {
                if (state.selected_row < @as(i32, @intCast(state.row_count)) - 1) {
                    state.selected_row += 1;
                    result.selection_changed = true;
                    state.ensureVisible(visible_rows);
                }
            },
            .left => {
                if (state.selected_col > 0) {
                    state.selected_col -= 1;
                    result.selection_changed = true;
                }
            },
            .right => {
                if (state.selected_col < @as(i32, @intCast(col_count)) - 1) {
                    state.selected_col += 1;
                    result.selection_changed = true;
                }
            },
            .home => {
                if (ctx.input.modifiers.ctrl) {
                    // Ctrl+Home: go to first row
                    state.selected_row = 0;
                    state.scroll_row = 0;
                } else {
                    // Home: go to first column
                    state.selected_col = 0;
                }
                result.selection_changed = true;
            },
            .end => {
                if (ctx.input.modifiers.ctrl) {
                    // Ctrl+End: go to last row
                    state.selected_row = @as(i32, @intCast(state.row_count)) - 1;
                    state.ensureVisible(visible_rows);
                } else {
                    // End: go to last column
                    state.selected_col = @as(i32, @intCast(col_count)) - 1;
                }
                result.selection_changed = true;
            },
            .page_up => {
                const jump = @as(i32, @intCast(visible_rows));
                state.selected_row = @max(0, state.selected_row - jump);
                state.ensureVisible(visible_rows);
                result.selection_changed = true;
            },
            .page_down => {
                const jump = @as(i32, @intCast(visible_rows));
                const max_row = @as(i32, @intCast(state.row_count)) - 1;
                state.selected_row = @min(max_row, state.selected_row + jump);
                state.ensureVisible(visible_rows);
                result.selection_changed = true;
            },
            .tab => {
                // Tab: next cell, Shift+Tab: previous cell
                // Only handle if config.handle_tab is true
                if (config.handle_tab) {
                    if (ctx.input.modifiers.shift) {
                        if (state.selected_col > 0) {
                            state.selected_col -= 1;
                        } else if (state.selected_row > 0) {
                            state.selected_row -= 1;
                            state.selected_col = @as(i32, @intCast(col_count)) - 1;
                        }
                    } else {
                        if (state.selected_col < @as(i32, @intCast(col_count)) - 1) {
                            state.selected_col += 1;
                        } else if (state.selected_row < @as(i32, @intCast(state.row_count)) - 1) {
                            state.selected_row += 1;
                            state.selected_col = 0;
                        }
                    }
                    state.ensureVisible(visible_rows);
                    result.selection_changed = true;
                }
                // If handle_tab is false, Tab is handled by external focus system
            },
            .enter => {
                // Enter: start editing if not editing
                if (!state.editing and config.allow_edit) {
                    if (state.selectedCell()) |cell| {
                        const current_text = get_cell(cell.row, cell.col);
                        state.startEditing(current_text);
                        result.edit_started = true;
                    }
                }
            },
            .escape => {
                // Escape: cancel editing
                if (state.editing) {
                    state.stopEditing();
                    result.edit_ended = true;
                }
            },
            else => {},
        }
    }

    // F2 also starts editing
    if (ctx.input.keyPressed(.f2) and !state.editing and config.allow_edit) {
        if (state.selectedCell()) |cell| {
            const current_text = get_cell(cell.row, cell.col);
            state.startEditing(current_text);
            result.edit_started = true;
        }
    }

    // Handle edit commit for Enter during editing
    if (state.editing and ctx.input.keyPressed(.enter)) {
        if (state.selectedCell()) |cell| {
            const edit_text = state.getEditText();

            // Validate before commit if validator provided
            var should_commit = true;
            if (validate) |validate_fn| {
                const validation = validate_fn(cell.row, cell.col, edit_text);
                if (!validation.valid) {
                    // Don't commit, mark error
                    state.addCellError(cell.row, cell.col, validation.message);
                    result.validation_failed = true;
                    result.validation_message = validation.message;
                    should_commit = false;
                } else {
                    // Clear any previous error on this cell
                    state.clearCellError(cell.row, cell.col);
                }
            }

            if (should_commit) {
                if (on_edit) |edit_fn| {
                    edit_fn(cell.row, cell.col, edit_text);
                }
                state.stopEditing();
                result.cell_edited = true;
                result.edit_ended = true;
            }
        }
    }

    // Row operations (only when not editing)
    if (!state.editing and config.allow_row_operations) {
        // Ctrl+N: Insert new row
        if (ctx.input.keyPressed(.n) and ctx.input.modifiers.ctrl) {
            result.row_added = true;
            // Insert after current row, or append if no selection
            if (state.selected_row >= 0) {
                result.insert_at = state.selected_row + 1;
            } else {
                result.insert_at = -1; // Append
            }
        }

        // Delete: Delete selected row(s)
        if (ctx.input.keyPressed(.delete)) {
            const count = state.getSelectedRows(&result.delete_rows);
            if (count > 0) {
                result.row_deleted = true;
                result.delete_count = count;
            } else if (state.selected_row >= 0) {
                // Single row delete (from selected_row)
                result.row_deleted = true;
                result.delete_rows[0] = @intCast(state.selected_row);
                result.delete_count = 1;
            }
        }

        // Ctrl+A: Select all rows
        if (ctx.input.keyPressed(.a) and ctx.input.modifiers.ctrl and config.allow_multi_select) {
            state.selectAllRows();
            result.select_all = true;
            result.selection_changed = true;
        }
    }

    // Incremental search (only when not editing and no modifiers pressed)
    if (!state.editing and !ctx.input.modifiers.ctrl and !ctx.input.modifiers.alt) {
        const text_in = ctx.input.getTextInput();
        if (text_in.len > 0) {
            // Add characters to search buffer
            for (text_in) |char| {
                if (char >= 32 and char < 127) { // Printable ASCII
                    const search_term = state.addSearchChar(char, ctx.current_time_ms);

                    // Search for matching row in first column (column 0)
                    if (search_term.len > 0) {
                        var found_row: ?usize = null;

                        // Search from current position first, then wrap
                        const start_row: usize = if (state.selected_row >= 0)
                            @intCast(state.selected_row)
                        else
                            0;

                        // Search from start_row to end
                        var row: usize = start_row;
                        while (row < state.row_count) : (row += 1) {
                            const cell_text = get_cell(row, 0);
                            if (startsWithIgnoreCase(cell_text, search_term)) {
                                found_row = row;
                                break;
                            }
                        }

                        // If not found, wrap to beginning
                        if (found_row == null and start_row > 0) {
                            row = 0;
                            while (row < start_row) : (row += 1) {
                                const cell_text = get_cell(row, 0);
                                if (startsWithIgnoreCase(cell_text, search_term)) {
                                    found_row = row;
                                    break;
                                }
                            }
                        }

                        // Move selection if found
                        if (found_row) |row_idx| {
                            state.selected_row = @intCast(row_idx);
                            state.ensureVisible(visible_rows);
                            result.selection_changed = true;
                            result.search_matched = true;
                        }
                    }
                }
            }
        }
    }
}

// =============================================================================
// Helper Functions
// =============================================================================

/// Case-insensitive prefix match for incremental search
pub fn startsWithIgnoreCase(haystack: []const u8, needle: []const u8) bool {
    if (needle.len > haystack.len) return false;
    if (needle.len == 0) return true;

    for (needle, 0..) |needle_char, i| {
        const haystack_char = haystack[i];
        // Simple ASCII case-insensitive comparison
        const needle_lower = if (needle_char >= 'A' and needle_char <= 'Z')
            needle_char + 32
        else
            needle_char;
        const haystack_lower = if (haystack_char >= 'A' and haystack_char <= 'Z')
            haystack_char + 32
        else
            haystack_char;

        if (needle_lower != haystack_lower) return false;
    }
    return true;
}