//! CellEditor - Editor de celda overlay para edición inline
//!
//! Dibuja un campo de texto sobre una celda para edición estilo Excel.
//! Utiliza el edit_buffer del VirtualAdvancedTableState.

const std = @import("std");
const Context = @import("../../core/context.zig").Context;
const Command = @import("../../core/command.zig");
const Style = @import("../../core/style.zig");
const Input = @import("../../core/input.zig");
const types = @import("types.zig");
const state_mod = @import("state.zig");

const CellGeometry = types.CellGeometry;
const VirtualAdvancedTableState = state_mod.VirtualAdvancedTableState;

/// Colores del editor de celda
pub const CellEditorColors = struct {
    background: Style.Color = Style.Color.rgb(255, 255, 255),
    border: Style.Color = Style.Color.rgb(0, 120, 215), // Azul Windows
    text: Style.Color = Style.Color.rgb(0, 0, 0),
    cursor: Style.Color = Style.Color.rgb(0, 0, 0),
    selection: Style.Color = Style.Color.rgb(173, 214, 255),
};

/// Resultado del procesamiento del CellEditor
pub const CellEditorResult = struct {
    /// El usuario presionó Enter o Tab (commit)
    committed: bool = false,

    /// El usuario presionó Escape
    escaped: bool = false,

    /// El texto cambió
    text_changed: bool = false,

    /// Navegación solicitada después de commit
    navigate: NavigateDirection = .none,

    pub const NavigateDirection = enum {
        none,
        next_cell, // Tab
        prev_cell, // Shift+Tab
        next_row, // Enter o ↓
        prev_row, // ↑
    };
};

/// Dibuja el editor de celda overlay
/// Retorna resultado con acciones del usuario
pub fn drawCellEditor(
    ctx: *Context,
    state: *VirtualAdvancedTableState,
    geom: CellGeometry,
    colors: CellEditorColors,
) CellEditorResult {
    var result = CellEditorResult{};

    if (!state.isEditing()) return result;

    // Padding interno
    const padding: i32 = 2;

    // Fondo blanco
    ctx.pushCommand(Command.rect(
        geom.x,
        geom.y,
        geom.w,
        geom.h,
        colors.background,
    ));

    // Borde azul (indica edición activa)
    ctx.pushCommand(Command.rectOutline(
        geom.x,
        geom.y,
        geom.w,
        geom.h,
        colors.border,
    ));

    // Texto actual
    const text = state.getEditText();
    ctx.pushCommand(Command.text(
        geom.x + padding,
        geom.y + padding,
        text,
        colors.text,
    ));

    // Cursor (línea vertical parpadeante)
    // Calcular posición X del cursor basado en edit_cursor
    const cursor_x = geom.x + padding + @as(i32, @intCast(state.edit_cursor * 7)); // ~7px por caracter (monospace)
    const cursor_visible = (state.frame_count / 30) % 2 == 0; // Parpadeo cada 30 frames

    if (cursor_visible) {
        ctx.pushCommand(Command.rect(
            cursor_x,
            geom.y + padding,
            1, // 1px de ancho
            geom.h - (padding * 2),
            colors.cursor,
        ));
    }

    // Procesar input de teclado
    result = handleCellEditorInput(ctx, state);

    return result;
}

/// Procesa input de teclado para el editor
fn handleCellEditorInput(ctx: *Context, state: *VirtualAdvancedTableState) CellEditorResult {
    var result = CellEditorResult{};

    // Procesar eventos de tecla
    for (ctx.input.getKeyEvents()) |event| {
        if (!event.pressed) continue;

        switch (event.key) {
            .escape => {
                result.escaped = true;
                return result;
            },
            .enter => {
                result.committed = true;
                result.navigate = .next_row;
                return result;
            },
            .tab => {
                result.committed = true;
                if (event.modifiers.shift) {
                    result.navigate = .prev_cell;
                } else {
                    result.navigate = .next_cell;
                }
                return result;
            },
            .up => {
                result.committed = true;
                result.navigate = .prev_row;
                return result;
            },
            .down => {
                result.committed = true;
                result.navigate = .next_row;
                return result;
            },
            .left => {
                // Mover cursor a la izquierda
                if (state.edit_cursor > 0) {
                    state.edit_cursor -= 1;
                }
            },
            .right => {
                // Mover cursor a la derecha
                if (state.edit_cursor < state.edit_buffer_len) {
                    state.edit_cursor += 1;
                }
            },
            .home => {
                state.edit_cursor = 0;
            },
            .end => {
                state.edit_cursor = state.edit_buffer_len;
            },
            .backspace => {
                if (state.edit_cursor > 0 and state.edit_buffer_len > 0) {
                    // Eliminar caracter antes del cursor
                    const pos = state.edit_cursor - 1;
                    // Mover caracteres hacia la izquierda
                    std.mem.copyForwards(
                        u8,
                        state.edit_buffer[pos .. state.edit_buffer_len - 1],
                        state.edit_buffer[pos + 1 .. state.edit_buffer_len],
                    );
                    state.edit_buffer_len -= 1;
                    state.edit_cursor -= 1;
                    result.text_changed = true;
                }
            },
            .delete => {
                if (state.edit_cursor < state.edit_buffer_len) {
                    // Eliminar caracter en el cursor
                    std.mem.copyForwards(
                        u8,
                        state.edit_buffer[state.edit_cursor .. state.edit_buffer_len - 1],
                        state.edit_buffer[state.edit_cursor + 1 .. state.edit_buffer_len],
                    );
                    state.edit_buffer_len -= 1;
                    result.text_changed = true;
                }
            },
            else => {},
        }
    }

    // Procesar texto ingresado (caracteres imprimibles)
    const text_input = ctx.input.getTextInput();
    if (text_input.len > 0) {
        // Insertar caracteres en la posición del cursor
        for (text_input) |c| {
            if (state.edit_buffer_len < state.edit_buffer.len - 1) {
                // Hacer espacio moviendo caracteres hacia la derecha
                if (state.edit_cursor < state.edit_buffer_len) {
                    var i = state.edit_buffer_len;
                    while (i > state.edit_cursor) : (i -= 1) {
                        state.edit_buffer[i] = state.edit_buffer[i - 1];
                    }
                }
                state.edit_buffer[state.edit_cursor] = c;
                state.edit_buffer_len += 1;
                state.edit_cursor += 1;
                result.text_changed = true;
            }
        }
    }

    return result;
}

// =============================================================================
// Tests
// =============================================================================

test "CellEditor types" {
    const colors = CellEditorColors{};
    _ = colors;

    const result = CellEditorResult{};
    _ = result;
}