const std = @import("std");
const Storage = @import("../root.zig");

const exif = @import("exif.zig");

const id_size = 32;

const log = std.log.scoped(.image);

fn new_id() [id_size]u8 {
    var buffer: [id_size]u8 = undefined;
    var raw_buffer: [id_size / 2]u8 = undefined;
    std.crypto.random.bytes(&raw_buffer);

    var writer = std.Io.Writer.fixed(buffer[0..]);
    writer.print("{x}", .{raw_buffer}) catch unreachable;

    return buffer[0..].*;
}

const Self = @This();

id: []const u8,
timestamp: ?i64,

pub fn new(
    storage: *Storage,
    reader: *std.Io.Reader,
    size: usize,
) !Self {
    var dir = try storage.dir.openDir("image", .{});
    defer dir.close();

    var self: Self = undefined;

    self.id = try storage.allocator.dupe(u8, &new_id());

    var file_name: [id_size + 4]u8 = undefined;
    @memcpy(file_name[0..id_size], self.id);
    @memcpy(file_name[id_size..], ".jpg");

    var image_file = try dir.createFile(&file_name, .{});
    defer image_file.close();

    var buffer: [1024]u8 = undefined;
    var file_writer = image_file.writer(&buffer);

    try reader.streamExact(&file_writer.interface, size);

    try file_writer.interface.flush();

    log.info("uploaded {s} [{} bytes]", .{ self.id, size });

    self.timestamp = try load_timestamp(storage, self.id);

    return self;
}

pub fn delete(self: *Self, storage: *Storage) !void {
    var dir = try storage.dir.openDir("image", .{});
    defer dir.close();

    var file_name: [id_size + 4]u8 = undefined;
    @memcpy(file_name[0..id_size], self.id);
    @memcpy(file_name[id_size..], ".jpg");

    try dir.deleteFile(&file_name);
}

pub fn init(storage: *Storage, id: []const u8) !Self {
    return .{
        .id = try storage.allocator.dupe(u8, id),
        .timestamp = try load_timestamp(storage, id),
    };
}

pub fn file(self: *Self, storage: *Storage) !std.fs.File {
    var dir = storage.dir.openDir("image", .{}) catch blk: {
        try storage.dir.makeDir("image");
        break :blk try storage.dir.openDir("image", .{});
    };
    defer dir.close();

    var file_name: [id_size + 4]u8 = undefined;
    @memcpy(file_name[0..id_size], self.id);
    @memcpy(file_name[id_size..], ".jpg");

    return dir.openFile(&file_name, .{});
}

pub fn deinit(self: *Self, allocator: std.mem.Allocator) void {
    allocator.free(self.id);
}

fn load_timestamp(storage: *Storage, id: []const u8) !?i64 {
    var dir = storage.dir.openDir("image", .{}) catch blk: {
        try storage.dir.makeDir("image");
        break :blk try storage.dir.openDir("image", .{});
    };
    defer dir.close();

    var file_name: [id_size + 4]u8 = undefined;
    @memcpy(file_name[0..id_size], id);
    @memcpy(file_name[id_size..], ".jpg");

    var path_buffer: [std.fs.max_path_bytes:0]u8 = std.mem.zeroes([std.fs.max_path_bytes:0]u8);
    const path = try dir.realpath(&file_name, &path_buffer);

    return exif.get_date_time(@ptrCast(path));
}